Author Topic: Dave's fault finding technique and other stuff.............  (Read 18505 times)

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Offline Towger

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Re: Dave's fault finding technique and other stuff.............
« Reply #25 on: June 19, 2014, 06:05:56 am »
Some workshops have ESR meters but good techs never need to use them, for instance we never had one at Panasonic.

A useful, fairly cheep item of kit, which has come into its own in recent years with the widespread use of cheap switchmode power supplies, with even cheaper Chinese capacitors. Of course not a problem Panasonic should have with their own brand high quality capacitor factories.
 

Offline Towger

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Re: Dave's fault finding technique and other stuff.............
« Reply #26 on: June 19, 2014, 06:17:31 am »
He was the lead designer, I was the junior maybe you never worked in a large company before or maybe you are just different.
Richard Dyson?
 

Online Rasz

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Re: Dave's fault finding technique and other stuff.............
« Reply #27 on: June 19, 2014, 06:25:00 am »
Some workshops have ESR meters but good techs never need to use them, for instance we never had one at Panasonic.

Thats because authorised repair centres deal mainly in warranty repairs = hardware that is less than 1-2, 3 at max years old. Panasonic using genuine Panasonic caps has to help too.
 Ordinary TV/Monitor/switching power supply/other consumer crap repair procedure starts with swapping all the mayor caps, often without even measuring them. This is precisely because of shitty caps being used for the last 10 years. Its faster (=cheaper) to swap 5 caps than to measure and ponder over them.

Wow that's a bit strong. Really you're going to call me a liar?
Your are not in the repair industry and haven't been since 1989/90 but profess to know "A professional TV tech probably could likely have told you the fault without even opening the case." All I said is, "it would have been a guess" anyone can guess of course but that doesn't mean they "know" and if he had said "It is the caps" he would have been wrong, as you found.

Yes, professional repairman can guess correctly from experience with high level of confidence just by symptoms alone. What exactly are you arguing about here? When I see dead Core2 laptop I dont even have to open it to guess its the Nvidia GPU (99% of cases). When I see Benq LCD that fails to start I already know its transistors in the inverter etc. There are plenty of typical faults for particular brands/type of equipment.
« Last Edit: June 19, 2014, 06:28:32 am by Rasz »
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Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #28 on: June 19, 2014, 06:27:19 am »
Some workshops have ESR meters but good techs never need to use them, for instance we never had one at Panasonic.

A useful, fairly cheep item of kit, which has come into its own in recent years with the widespread use of cheap switchmode power supplies, with even cheaper Chinese capacitors. Of course not a problem Panasonic should have with their own brand high quality capacitor factories.

Yikees this is getting harder.... Please don't assume that Panasonic uses only Panasonic Capacitors. Maybe Dave will get the chance to show that most major companies use many other brands of components too. What major companies do, which is probably different from smaller companies is mass testing of second sourced components, this insures somewhat their long term reliability.
I would say most cheap capacitors show visual signs of failure, bulging tops and/or leakage around the base. In circuit testing is not conclusive in all cases.
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #29 on: June 19, 2014, 06:32:19 am »
Some workshops have ESR meters but good techs never need to use them, for instance we never had one at Panasonic.

Thats because authorised repair centres deal mainly in warranty repairs = hardware that is less than 1-2, 3 at max years old. Panasonic using genuine Panasonic caps has to help too.
 Ordinary TV/Monitor/switching power supply/other consumer crap repair procedure starts with swapping all the mayor caps, often without even measuring them. This is precisely because of shitty caps being used for the last 10 years. Its faster (=cheaper) to swap 5 caps than to measure and ponder over them.

Wow that's a bit strong. Really you're going to call me a liar?
Your are not in the repair industry and haven't been since 1989/90 but profess to know "A professional TV tech probably could likely have told you the fault without even opening the case." All I said is, "it would have been a guess" anyone can guess of course but that doesn't mean they "know" and if he had said "It is the caps" he would have been wrong, as you found.

Yes, professional repairman can guess correctly from experience with high level of confidence just by symptoms alone. What exactly are you arguing about here? When I see dead Core2 laptop I dont even have to open it to guess its the Nvidia GPU (99% of cases). When I see Benq LCD that fails to start I already know its transistors in the inverter etc. There are plenty of typical faults for particular brands/type of equipment.

Appears to be the difference between "know" and "guess". Just like you said in your post "I dont even have to open it to guess its the Nvidia GPU (99% of cases)." so you guess but cannot be 100% certain. I really don't want to argue this point as it is really irrelevant. I'm not sure as to why he pounced on it.
 

Offline IanJ

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Re: Dave's fault finding technique and other stuff.............
« Reply #30 on: June 19, 2014, 06:49:34 am »
If he had it would have been a guess, you did the right thing by opening it up.

Come on, any experienced person in this situation is going to have a guess up front.
If you, as professional repair tech claim you don't do that, then I'm going to call you liar  :P

Wow that's a bit strong. Really you're going to call me a liar?
Your are not in the repair industry and haven't been since 1989/90 but profess to know "A professional TV tech probably could likely have told you the fault without even opening the case." All I said is, "it would have been a guess" anyone can guess of course but that doesn't mean they "know" and if he had said "It is the caps" he would have been wrong, as you found.

Not sure I understand the purpose of this thread now..........but all I can say is:-

EEVBlog = Electronics entertainment centred around Dave's many years of professional and non-professional experiences & knowledge. Look over his shoulder as he teaches us, shares with us & guesses with us.

With that in mind......ALL his videos are spot on.

Ian.
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Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #31 on: June 19, 2014, 07:17:19 am »
If he had it would have been a guess, you did the right thing by opening it up.

Come on, any experienced person in this situation is going to have a guess up front.
If you, as professional repair tech claim you don't do that, then I'm going to call you liar  :P

Wow that's a bit strong. Really you're going to call me a liar?
Your are not in the repair industry and haven't been since 1989/90 but profess to know "A professional TV tech probably could likely have told you the fault without even opening the case." All I said is, "it would have been a guess" anyone can guess of course but that doesn't mean they "know" and if he had said "It is the caps" he would have been wrong, as you found.

Not sure I understand the purpose of this thread now..........but all I can say is:-

EEVBlog = Electronics entertainment centred around Dave's many years of professional and non-professional experiences & knowledge. Look over his shoulder as he teaches us, shares with us & guesses with us.

With that in mind......ALL his videos are spot on.

Ian.

Yes it went off track and I'm basically done with it.
Of course anyone is free to continue to pick it apart but for what it's worth I still stand by my first post and first post only.
The intention was to help others out there to follow a logical sequence for fault finding. I thought my 30 years of training Technicians in a major company would be helpful and was using some of Dave's not so logical methods as an example but apparently I failed.
For what it's worth - If I see questions that are on the subject of "fault finding help" and are not just fanboy jives, I will be happy to answer them.
« Last Edit: June 19, 2014, 07:19:09 am by What_NZ »
 

Online Kjelt

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Re: Dave's fault finding technique and other stuff.............
« Reply #32 on: June 19, 2014, 07:36:32 am »
I think a lot of people forget that Dave is not only the main "actor" in the videos but simultaneously the cameraman and director.
This makes it much harder to be your normal self and show the same capabilities as if you had a discovery channel team filming and doing all the other work,
use multiple takes, etc.
One of the best examples of this is the solder paste demo video with the pcb's and stencil from free_electron's book.
I never ever saw such a worse demo of solderpaste application and use but he had to do three things at the same time.
I am sure that if he had the sole task doing it it would have been much better as others experienced doing it a couple of times.
Still I admire his balls for putting that video on the air, showing he is not infallible and still making his point.
What I do find good in criticism is if there are any safety risks, for instance the person saying an isolation transformer should be used and shown to be used in the video.
Repairing a life opened tv should have a lot of warnings for young ones not to do this if they are not experienced since it potentially could kill you.
At least the old tv's, unsure if the new ones have an isolated SMPS and it is perfectly safe.
Maybe a good idea to place a standard warning before this kind of videos Dave?
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #33 on: June 19, 2014, 08:03:04 am »
<SNIP>What I do find good in criticism is if there are any safety risks, for instance the person saying an isolation transformer should be used and shown to be used in the video.
Repairing a life opened tv should have a lot of warnings for young ones not to do this if they are not experienced since it potentially could kill you.
At least the old tv's, unsure if the new ones have an isolated SMPS and it is perfectly safe.
Maybe a good idea to place a standard warning before this kind of videos Dave?

Oh you are so right!
Repairing anything that is powered by the AC Mains voltage or generates high voltage internally should raise the safety flag as high as a kite! Often but not all manufactures will show on the PCB's warning symbols where there is high voltage or lethal voltages. No matter what the product, personal safety and the safety of the customer is the most important thing, life is way more precious than a $300 whatever product.
Always treat any so called safety product with respect, know how it works and what its limitations are, whether it be an ELCB (Earth Leakage Circuit Breaker), RCD (Residual Current Device) or Isolating transformer. Always assume something is "hot/live" then check whether it is or is not, before touching or connecting any grounded test equipment or any equipment that is Double Insulated but has an exposed metal chassis.
Actually it would be a great idea for a new EEVblog video.
« Last Edit: June 19, 2014, 10:19:32 am by What_NZ »
 

Online vk6zgo

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Re: Dave's fault finding technique and other stuff.............
« Reply #34 on: June 19, 2014, 08:06:36 am »
Hi there,

I'm a long time watcher of Dave's video's and find most of the things he shows and talks about to be informative, for some strange reason I also enjoy mailbag too. I have no reason to doubt his credentials and life experiences, actually I'm a fellow atheist so I like the guy for that reason alone!
I didn't want to join the forum to be a basher and I hope this first post is not taken the wrong way. Dave is very good at what he does in other areas but fault finding has me thinking most of the time "WTF is he doing......" and the latest Soniq TV repair video was the proverbial straw!
I don't want to make this a rant so will just cut to what I taught Electronics Technicians for some 30 odd years as a Workshop Manager and Trainer for Panasonic.
Do not deviate from these important steps -

1/ Confirm the customers description of the fault, also confirm the correct functionality of overall operation
2/ Check visually the outside for anything unusual or signs of damage, physical damage, liquid ingress etc
3/ Open the unit and recheck customers description of the fault, also reconfirm the correct functionality of overall operation
4/ Start a complete visual inspection looking for anything unusual, charring, over heating, damaged components, corrosion, obvious dry joints

Next -

- Always be aware of jumping to conclusions and following garden paths, don't go too deep too quickly. Reassess every now and then, why and what I am doing.

There are a number of branches the next steps could follow depending on the fault but basically in no particular order -

- Check for intermittents, tap test, flexing the PCB either by hand (safety first of course) or an insulated object.
- Alternating between a can of Freeze and a Hair dryer can help to isolate temperature related faults. Also helpful are small gas powered hot air blowers for pin point heating, even the hot tip of a soldering iron can be useful (be careful it is grounded)

- If you need to start tracing a fault then start with Power supply, Oscillators, Resets
- Don't assume ground is contiguous throughout the whole unit. I have seen many a technician fooled by an open circuit/floating ground while testing another PCB from a common ground point. Shift the ground point to the Circuit/PCB you are testing or check the ground continuity.
- Never assume that just because you have voltage you don't have excessive ripple.
- Before replacing a fuse (of any type) ask yourself "why did it fail?" check the resistance of the circuit on the secondary side.
- Carefully unplug, check and reconnect all relevant connectors
- Never change the design of a circuit or 'band-aid" components. You are not the designer and the circuit worked fine before it failed so fix it properly.

Always be aware of your personal safety, and the safety of the customer. Even if you are repairing your Mum's TV you don't want to kill her or burn the house down due to your shoddy repair - know your limitations and seek professional help if needed.

Of course there are things I have forgotten to mention.

My final point is, you can fault find with just a Multimeter. It is the most useful piece of test equipment you will have, try and get yourself an old type Analogue Multimeter too. An oscilloscope is also helpful, it doesn't have to be a storage one as I still use my analogue scope of 20 years. I know Dave uses some of the equipment he has for educational value but honestly you don't need them, they are just "bling" and can confuse rather than clarify a problem.

If you read this Dave, keep up the good work. I do admire what you are doing.

Back in the day,I was,among other things,responsible for the repair,& availability of Picture Monitors at a TV Studio.

This also included some top end Domestic TV sets.

Management decided to outsource the repair of some of the big Sony 27" Domestics,as they thought things were getting on top of us a bit!

We attached a note to the first set saying what we had checked,hoping it would be useful to the Serviceman.
After a couple of weeks we got a call that it was fixed.

When I picked it up,I noticed their job sheet attached to it.

Under "nature of fault",it said "doesn't work"!

So much for:-
"1/ Confirm the customers description of the fault, also confirm the correct functionality of overall operation"

Ever"tigers for punishment",we sent another of these sets out to another Service company for a few problems.

We got a call:- "The tube is faulty!"

"OK",we said,& despatched a "regunned" tube to them,with strict instructions to return the old one intact so it could also be "regunned".

We got the tube back with the end knocked off,& the TV with the new tube "fitted",but not in any way converged,or any purity adjustments done.
We spent half a day finishing their job!
Luckily,the regunning place still managed to do the tube OK.

There was little talk about "outsourcing" from then on! ;D

With the "in-house " stuff,when Production folk wanted a certain number of Monitors,you needed to supply them--or else!
There was not any case where you could write off a unit as "beyond economical repair",so we went to fairly extreme lengths to keep them available & meeting Broadcast specs.

Due to time constraints,we quite often had to bend the words if not the spirit of  your injunction:-

"- Never change the design of a circuit or 'band-aid" components. You are not the designer and the circuit worked fine before it failed so fix it properly."


With some equipment,it didn't "work fine",so the same fault would recur-----for no other reason than the use of inadequate components in the original design.

Even with good designs,it was often necessary to fit different components because the original ones were unobtainable.
In every case,this led to a reliable & safe repair.


 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #35 on: June 19, 2014, 08:30:14 am »
<SNIP>

Back in the day,I was,among other things,responsible for the repair,& availability of Picture Monitors at a TV Studio.

This also included some top end Domestic TV sets.

Management decided to outsource the repair of some of the big Sony 27" Domestics,as they thought things were getting on top of us a bit!

We attached a note to the first set saying what we had checked,hoping it would be useful to the Serviceman.
After a couple of weeks we got a call that it was fixed.

When I picked it up,I noticed their job sheet attached to it.

Under "nature of fault",it said "doesn't work"!

So much for:-
"1/ Confirm the customers description of the fault, also confirm the correct functionality of overall operation"

Ever"tigers for punishment",we sent another of these sets out to another Service company for a few problems.

We got a call:- "The tube is faulty!"

"OK",we said,& despatched a "regunned" tube to them,with strict instructions to return the old one intact so it could also be "regunned".

We got the tube back with the end knocked off,& the TV with the new tube "fitted",but not in any way converged,or any purity adjustments done.
We spent half a day finishing their job!
Luckily,the regunning place still managed to do the tube OK.

There was little talk about "outsourcing" from then on! ;D

With the "in-house " stuff,when Production folk wanted a certain number of Monitors,you needed to supply them--or else!
There was not any case where you could write off a unit as "beyond economical repair",so we went to fairly extreme lengths to keep them available & meeting Broadcast specs.

Due to time constraints,we quite often had to bend the words if not the spirit of  your injunction:-

"- Never change the design of a circuit or 'band-aid" components. You are not the designer and the circuit worked fine before it failed so fix it properly."


With some equipment,it didn't "work fine",so the same fault would recur-----for no other reason than the use of inadequate components in the original design.

Even with good designs,it was often necessary to fit different components because the original ones were unobtainable.
In every case,this led to a reliable & safe repair.

Yes I can relate to everything you said and it's great to hear your experiences...
I always thought it was funny when the customers said "it doesn't work" then after plugging it in and it working. I would say "oh it is working" then they may say something like "oh yeah but the auto focus is not working." because they were customers you couldn't be upset with them but when a service company did the same thing time and time again, I was on the phone to their manager.
I was also involved with regunning of picture tubes in the early day, personally I never liked it and always gave the customer the choice of new or regun and explained why there was such a price difference. Interesting what you say as our regunning would not regun a tube that had been "cracked", the risk of oxidisation was just too high.
I always asked the service centres to contact us before modifying as there may be an official ECN (Engineering Change Notice), especially for common faults. If it was something we didn't know about, we replaced the unit and investigated it ourselves, with the help and final decision of the Japanese design engineers.
The service industry is surly an interesting one.
« Last Edit: June 19, 2014, 08:40:55 am by What_NZ »
 

Offline all_repair

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Re: Dave's fault finding technique and other stuff.............
« Reply #36 on: June 19, 2014, 09:19:03 am »
So far I read about those that criticised Dave technique but when come to sharing theirs were nothing but an illustration of factory workman checklist that already knew the problem from the database nd fixes that need to be painted. 

It is nothing wrong to go through the ESR of the capacitors especially when they need to be checked anyway.

My technique is:  See See See See See See Think Think Think See See See Think Think See See Think and then "do".  It is a sin to me that Dave did not use his numerous powerful inspection microscopes at all.
« Last Edit: June 19, 2014, 09:53:49 am by all_repair »
 

Offline HackedFridgeMagnet

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Re: Dave's fault finding technique and other stuff.............
« Reply #37 on: June 19, 2014, 09:43:41 am »
Quote
Always treat any so called safety product with respect, know how it works and what its limitations are, whether it be an ELCB (Earth Leakage Circuit Breaker) or Isolating transformer. Always assume something is "hot/live" then check whether it is or is not, before touching or connecting any grounded test equipment or any equipment that is Double Insulated but has an exposed metal chassis.

I've got to admit I don't treat ELCBs with much respect, nobody installs them in switchboards anymore as the Aus/NZ rules mandate RCDs and have done for maybe 20 years.

How do you check something is "hot/live" or not? Just interested in a service technicians point of view on this one.

 

Offline gildasd

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Re: Dave's fault finding technique and other stuff.............
« Reply #38 on: June 19, 2014, 09:51:10 am »
Just a note on FLIR;

My university (HZS Antwerp) competes in solar boat challenges:
http://www.solar1races.com/
http://www.dongenergysolarchallenge.com/

And we have a FLIR that was bought to test IC engine radiators (for a thesis project I think).
It did not take long for the solar racing team to grab the FLIR to check the battery pack (more than a 100 LI-Ion modules) in about a second during pit stops.

Bad cells show up as much hotter or cooler, are quickly isolated for testing and/or replacement in the evening.

A meter would suffice if we were using a lead acid battery.

Or a hand on the forehead if using oars.
« Last Edit: June 19, 2014, 09:56:12 am by gildasd »
I'm electronically illiterate
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #39 on: June 19, 2014, 10:06:13 am »
Quote
Always treat any so called safety product with respect, know how it works and what its limitations are, whether it be an ELCB (Earth Leakage Circuit Breaker) or Isolating transformer. Always assume something is "hot/live" then check whether it is or is not, before touching or connecting any grounded test equipment or any equipment that is Double Insulated but has an exposed metal chassis.

I've got to admit I don't treat ELCBs with much respect, nobody installs them in switchboards anymore as the Aus/NZ rules mandate RCDs and have done for maybe 20 years.

How do you check something is "hot/live" or not? Just interested in a service technicians point of view on this one.

Good point!
One of the biggest limitations with ELCB's or RCD's is they won't necessarily trip if the leakage to earth is too low or if you are directly across the mains as there may not be enough leakage to earth.
Check "hot/live" with respect to ground/earth. Usually the earth of a mains socket is sufficient. It worthwhile checking for both DC and AC voltages.
« Last Edit: June 19, 2014, 10:17:47 am by What_NZ »
 

Offline EEVblog

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Re: Dave's fault finding technique and other stuff.............
« Reply #40 on: June 19, 2014, 10:22:59 am »
Wow that's a bit strong. Really you're going to call me a liar?

Relax, I was kidding, and trying to point out that you or anyone else would also have a guess at the fault before opening the case, just like I did. That's the nature of experienced technical people.
My problem is I do it on camera, warts and all for the entire world to see, and hence cop it every time I get anything even slightly wrong, or in this case, supposedly in the wrong order  ::)
 

Offline HackedFridgeMagnet

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Re: Dave's fault finding technique and other stuff.............
« Reply #41 on: June 19, 2014, 10:36:48 am »
Quote
Check "hot/live" with respect to ground/earth. Usually the earth of a mains socket is sufficient. It worthwhile checking for both DC and AC voltages.

My point here is that "hot" is slang for active and sometimes people use this term synonymously with "live".

But in the wiring rules AS/NZ 3000 the neutral is considered "live". I guess this is the case for mains rated equipment.

Anyway the only way to check that the chassis is not live is to pull the plug out of the wall and measure the insulation between the Chassis and both the Neutral and Live conductors.
Measuring the voltage doesn't check this.

 

Offline EEVblog

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Re: Dave's fault finding technique and other stuff.............
« Reply #42 on: June 19, 2014, 10:45:32 am »
Still I admire his balls for putting that video on the air, showing he is not infallible and still making his point.

I don't see any "balls" in releasing this at all.
I made a (very reasonable) guess at the fault based on the symptoms, and I said that's what I'd check first and that's what I did.
It didn't turn out to be the problem, but so what? All I said was it was likely.

People have to remember that all up this is probably about 10 minutes worth of actual troubleshooting before I found the problem and few minutes more fixing it. I probably spent more time undoing screws and clearing the bench than finding the problem.  So I see this as nothing but an excellent result.
The videos are longer because that's the nature of the beast.
And if all I got was one person complaining I measured the caps first instead of the voltages, and one person complaining I used a 3000X scope to measure basic ripple, then I see this as a very successful video.
 

Offline EEVblog

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Re: Dave's fault finding technique and other stuff.............
« Reply #43 on: June 19, 2014, 10:50:34 am »
intention was to help others out there to follow a logical sequence for fault finding. I thought my 30 years of training Technicians in a major company would be helpful and was using some of Dave's not so logical methods as an example but apparently I failed.

Please explain how my guessing that it might be the capacitors based on symptoms, and then checking said capacitors (that should be checked anyway), then moving onto the voltages, and then mechanical stuff before the fault was found in maybe 10 minutes, was in any way illogical?
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #44 on: June 19, 2014, 11:35:43 am »
Quote
Check "hot/live" with respect to ground/earth. Usually the earth of a mains socket is sufficient. It worthwhile checking for both DC and AC voltages.

My point here is that "hot" is slang for active and sometimes people use this term synonymously with "live".

But in the wiring rules AS/NZ 3000 the neutral is considered "live". I guess this is the case for mains rated equipment.

Anyway the only way to check that the chassis is not live is to pull the plug out of the wall and measure the insulation between the Chassis and both the Neutral and Live conductors.
Measuring the voltage doesn't check this.
IMO it is common in the Service industry to just say hot or live chassis (it doesn't mean Phase or Neutral) it may not be Electrical standards talk but you would instantly know what they meant by it.
Hmmm. Insulation would certainly test this for some situations but would fail for a chassis sitting at rectified mains voltage. I think I would feel safer measuring the AC and DC voltage. Well that is what is going to knock me for a six if I get it wrong.
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #45 on: June 19, 2014, 11:44:19 am »
Still I admire his balls for putting that video on the air, showing he is not infallible and still making his point.

I don't see any "balls" in releasing this at all.
I made a (very reasonable) guess at the fault based on the symptoms, and I said that's what I'd check first and that's what I did.
It didn't turn out to be the problem, but so what? All I said was it was likely.


People have to remember that all up this is probably about 10 minutes worth of actual troubleshooting before I found the problem and few minutes more fixing it. I probably spent more time undoing screws and clearing the bench than finding the problem.  So I see this as nothing but an excellent result.
The videos are longer because that's the nature of the beast.
And if all I got was one person complaining I measured the caps first instead of the voltages, and one person complaining I used a 3000X scope to measure basic ripple, then I see this as a very successful video.

Dave, Dave, Dave by all means have a go at me but please re-read Kjelts post again, he wasn't talking about the TV repair video. He was being oh so sympathetic towards you.....
 

Online vk6zgo

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Re: Dave's fault finding technique and other stuff.............
« Reply #46 on: June 19, 2014, 12:08:24 pm »
<SNIP>

Back in the day,I was,among other things,responsible for the repair,& availability of Picture Monitors at a TV Studio.

This also included some top end Domestic TV sets.

Management decided to outsource the repair of some of the big Sony 27" Domestics,as they thought things were getting on top of us a bit!

We attached a note to the first set saying what we had checked,hoping it would be useful to the Serviceman.
After a couple of weeks we got a call that it was fixed.

When I picked it up,I noticed their job sheet attached to it.

Under "nature of fault",it said "doesn't work"!

So much for:-
"1/ Confirm the customers description of the fault, also confirm the correct functionality of overall operation"

Ever"tigers for punishment",we sent another of these sets out to another Service company for a few problems.

We got a call:- "The tube is faulty!"

"OK",we said,& despatched a "regunned" tube to them,with strict instructions to return the old one intact so it could also be "regunned".

We got the tube back with the end knocked off,& the TV with the new tube "fitted",but not in any way converged,or any purity adjustments done.
We spent half a day finishing their job!
Luckily,the regunning place still managed to do the tube OK.

There was little talk about "outsourcing" from then on! ;D

With the "in-house " stuff,when Production folk wanted a certain number of Monitors,you needed to supply them--or else!
There was not any case where you could write off a unit as "beyond economical repair",so we went to fairly extreme lengths to keep them available & meeting Broadcast specs.

Due to time constraints,we quite often had to bend the words if not the spirit of  your injunction:-

"- Never change the design of a circuit or 'band-aid" components. You are not the designer and the circuit worked fine before it failed so fix it properly."


With some equipment,it didn't "work fine",so the same fault would recur-----for no other reason than the use of inadequate components in the original design.

Even with good designs,it was often necessary to fit different components because the original ones were unobtainable.
In every case,this led to a reliable & safe repair.

Yes I can relate to everything you said and it's great to hear your experiences...
I always thought it was funny when the customers said "it doesn't work" then after plugging it in and it working. I would say "oh it is working" then they may say something like "oh yeah but the auto focus is not working." because they were customers you couldn't be upset with them but when a service company did the same thing time and time again, I was on the phone to their manager.
I was also involved with regunning of picture tubes in the early day, personally I never liked it and always gave the customer the choice of new or regun and explained why there was such a price difference. Interesting what you say as our regunning would not regun a tube that had been "cracked", the risk of oxidisation was just too high.
I always asked the service centres to contact us before modifying as there may be an official ECN (Engineering Change Notice), especially for common faults. If it was something we didn't know about, we replaced the unit and investigated it ourselves, with the help and final decision of the Japanese design engineers.
The service industry is surly an interesting one.

As I pointed out,we never had a lot of time to play with,& being a long way from the manufacturers,there was little opportunity to talk to them.
Sony were very good when it came to getting parts,but even with them,we often had to use alternative Semiconductors from other sources.
They also sent the mod updates regularly,which was pretty rare with  the other suppliers.

Wellview in Perth WA did an excellent job with reguns,especially with the Broadcast standard tubes used in Sony Studio Monitors.

Normally we only replaced the tubes in these with new,but when there was a "financial squeeze" on,we used the reguns in this equipment,too.
They met all Broadcast standards,so we continued to use them until we could return to the original rule.

Wellview normally did not regun "cracked" tubes,but as we were good customers,he agreed to try in the case referred to in my last posting,with good results.
 

Offline What_NZ

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Re: Dave's fault finding technique and other stuff.............
« Reply #47 on: June 19, 2014, 12:31:36 pm »
<SNIP>
As I pointed out,we never had a lot of time to play with,& being a long way from the manufacturers,there was little opportunity to talk to them.
Sony were very good when it came to getting parts,but even with them,we often had to use alternative Semiconductors from other sources.
They also sent the mod updates regularly,which was pretty rare with  the other suppliers.

Wellview in Perth WA did an excellent job with reguns,especially with the Broadcast standard tubes used in Sony Studio Monitors.

Normally we only replaced the tubes in these with new,but when there was a "financial squeeze" on,we used the reguns in this equipment,too.
They met all Broadcast standards,so we continued to use them until we could return to the original rule.

Wellview normally did not regun "cracked" tubes,but as we were good customers,he agreed to try in the case referred to in my last posting,with good results.

Distances in NZ are not so great so I was probably tougher on our service centres. Over the years I became good friends with some of the people at Panasonic Australia the guy responsible for Perth and WA told me how he would drive about 12 hours, nearly half way to Broome and the guys from Broome would drive down to meet him at a Hotel so he could run a training course for them. This was all because Panasonic wouldn't pay for him to fly to Broome but driving long distances and getting paid for it was ok. Just seemed so strange to me........
I always wondered if the regunning plant regunned the "cracked" tubes anyway and sold them for a nice profit.
 

Offline Strada916

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Re: Dave's fault finding technique and other stuff.............
« Reply #48 on: June 19, 2014, 02:08:59 pm »
The way I see it. Someone thinks Dave did not go about HIS repair the way someone else would have. If you do not like it don't watch it. I enjoy these types of videos as it shows how HE went about it.

I guess my point is everyone is different, everyone tackles the same job differently. The fact that Dave made a video of it, is to entertain his audience. Not everyone is going to like what he does. If you do not like it then do not watch it. There are plenty of others who enjoyed it.
just my 2 cents worth.
The Bone, the Off-White, the Ivory or the Beige?
 

Offline nitro2k01

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Re: Dave's fault finding technique and other stuff.............
« Reply #49 on: June 19, 2014, 03:22:06 pm »
- Before replacing a fuse (of any type) ask yourself "why did it fail?" check the resistance of the circuit on the secondary side.
This was the only point in that rant that stood out to me as something he had forgotten to do while I was watching the video. Though as he mentioned earlier, he did check that off-camera.
Whoa! How the hell did Dave know that Bob is my uncle? Amazing!
 


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