Test Equipment Anonymous (TEA) group therapy thread

[Cerebus]

Currently, sitting here waiting for the workmen to arrive. We are having the bathroom refitted and were told that they would be with us this morning at 8.00AM, now 8.54AM and still sign of them. The job is supposed to take upto 2 weeks, thinking of taking friendly bets on the completion date 

Before placing any bets: Are the builders (1) Native English  ("Normal for Essex"), (2) Native English, or (3) Polish?

[bd139]

Currently, sitting here waiting for the workmen to arrive. We are having the bathroom refitted and were told that they would be with us this morning at 8.00AM, now 8.54AM and still sign of them. The job is supposed to take upto 2 weeks, thinking of taking friendly bets on the completion date 

Before placing any bets: Are the builders (1) Native English, or (2) Polish?

If they are English then it'll take 4 weeks due to the lateness, slacking and tea breaks.

[med6753]

Good write up as always 

Might have to refurb this 465B yet. Still waiting for that IC to turn up.  Hopefully today. If it checks out I’ll do a full clean and cal on it and sorted.

I didn't know yours had a bad IC. That must of happen when I was on vacation. I have a 465B parts mule and I would have given you the IC for cost of shipping only.

Yeah was a few days back. Details here:

discovery: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268857/#msg4268857

workaround: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268941/#msg4268941

first power up: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268986/#msg4268986

Dang it  . Paid £23 for a replacement NOS part here 

Yep, missed all that. I'm sure my parts mule has that IC. Oh well. 

[Cerebus]

Right, off for a walk along the Kent coast near Dungeness. If I'm home particularly late I may be able to light my way with my own eerie blue glow.

[ch_scr]

Condolences then. I'd rather drill screws through my feet than ever use that fustercluck again. Only app I ever found less intuitive than EagleCAD. 

mnem
*cringe*

Ah, so you've never used FreeCAD then? 

I can't see, why the hate on FreeCAD? I use it regularly for over 4 years, so somewhat biased 
Every CAD tool has it's hooks and it has to fit towards the way you think. Naturally, not everyone can work with every tool, people don't think the same way - and if the tool is structured contrary to your internal workflow, you'll never get along. You'll have to use a different tool, better suited to the way you think, to get good results and not hurt yourself continually. People try to get started in Freecad (or any tool really) for a month and not get anywhere, fall into that category. Of course the other thing are people coming from different tools, that expect things to work in a specific way.
But I've seen and helped people getting started in Kicad and Freecad around me, and would not say getting started in one is much harder than the other. Like FreeCAD, there are people hating on Kicad because "all the buttons are in the wrong places" - IMHO, for the same reason, see above.
Yes, FreeCAD allows you to do things in different ways, and some of them will shoot you in the foot later. Sometimes there is only one good way. Part of the learning curve is to learn to design around that. Yes, it would be better for that not to be the case, but I need it today. IMHO it's still the best bet for a free CAD tool with a wide feature set. It get's the job done and for a free CAM tool there is no alternative AFAIK. At least none that's easier to use, or even on par feature-wise. That said, to construct a whole machine / device, I would not want to do it in FreeCAD. But for the odd 3d printed or 2.5d milled part? More than good enough!
Edit: Just checked, I've designed over 150 "odd parts" so far, mostly 3d printed. 

[bd139]

Condolences then. I'd rather drill screws through my feet than ever use that fustercluck again. Only app I ever found less intuitive than EagleCAD. 

mnem
*cringe*

Ah, so you've never used FreeCAD then? 

I can't see, why the hate on FreeCAD? I use it regularly for over 4 years, so somewhat biased 
Every CAD tool has it's hooks and it has to fit towards the way you think. Naturally, not everyone can work with every tool, people don't think the same way - and if the tool is structured contrary to your internal workflow, you'll never get along. You'll have to use a different tool, better suited to the way you think, to get good results and not hurt yourself continually. People try to get started in Freecad (or any tool really) for a month and not get anywhere, fall into that category. Of course the other thing are people coming from different tools, that expect things to work in a specific way.
But I've seen and helped people getting started in Kicad and Freecad around me, and would not say getting started in one is much harder than the other. Like FreeCAD, there are people hating on Kicad because "all the buttons are in the wrong places" - IMHO, for the same reason, see above.
Yes, FreeCAD allows you to do things in different ways, and some of them will shoot you in the foot later. Sometimes there is only one good way. Part of the learning curve is to learn to design around that. Yes, it would be better for that not to be the case, but I need it today. IMHO it's still the best bet for a free CAD tool with a wide feature set. It get's the job done and for a free CAM tool there is no alternative AFAIK. At least none that's easier to use, or even on par feature-wise. That said, to construct a mechanism or whole machine / device, I would not want to do it in FreeCAD. But for the odd 3d printed or 2.5d milled part? More than good enough!

From my perspective it's just the clunk factor. It's ok but it needs a lot of polish.

Most of the open source software out there hasn't had "the 2nd 90%" of the development effort expended.

[Specmaster]

Currently, sitting here waiting for the workmen to arrive. We are having the bathroom refitted and were told that they would be with us this morning at 8.00AM, now 8.54AM and still sign of them. The job is supposed to take upto 2 weeks, thinking of taking friendly bets on the completion date 

Before placing any bets: Are the builders (1) Native English  ("Normal for Essex"), (2) Native English, or (3) Polish?

Well they have just arrived and certainly don't sound natives and they are already crashing and banging ripping out the old kit so they may be Polish after all.

[ch_scr]

Condolences then. I'd rather drill screws through my feet than ever use that fustercluck again. Only app I ever found less intuitive than EagleCAD. 

mnem
*cringe*

Ah, so you've never used FreeCAD then? 

I can't see, why the hate on FreeCAD? I use it regularly for over 4 years, so somewhat biased 
Every CAD tool has it's hooks and it has to fit towards the way you think. Naturally, not everyone can work with every tool, people don't think the same way - and if the tool is structured contrary to your internal workflow, you'll never get along. You'll have to use a different tool, better suited to the way you think, to get good results and not hurt yourself continually. People try to get started in Freecad (or any tool really) for a month and not get anywhere, fall into that category. Of course the other thing are people coming from different tools, that expect things to work in a specific way.
But I've seen and helped people getting started in Kicad and Freecad around me, and would not say getting started in one is much harder than the other. Like FreeCAD, there are people hating on Kicad because "all the buttons are in the wrong places" - IMHO, for the same reason, see above.
Yes, FreeCAD allows you to do things in different ways, and some of them will shoot you in the foot later. Sometimes there is only one good way. Part of the learning curve is to learn to design around that. Yes, it would be better for that not to be the case, but I need it today. IMHO it's still the best bet for a free CAD tool with a wide feature set. It get's the job done and for a free CAM tool there is no alternative AFAIK. At least none that's easier to use, or even on par feature-wise. That said, to construct a mechanism or whole machine / device, I would not want to do it in FreeCAD. But for the odd 3d printed or 2.5d milled part? More than good enough!

From my perspective it's just the clunk factor. It's ok but it needs a lot of polish.

Most of the open source software out there hasn't had "the 2nd 90%" of the development effort expended.

It's not too bad, but in principle I agree. I guess humans can get used to anything  I can't change it anyway, complaining won't help either - I'm just happy when they fix the odd bug. Some of the limitations and/or bugs come from the underlying free 3d solver engine that is also WIP, as most free software is. No way to change that either, there is a reason big company's sell their proven 3d solver engines for $$$.
Edit: on usability, there is a free tool called "Linegrinder". To get to the machine file from the gerber file needs an ungodly amount of clicks, every time you do it. That is real clunk! A command line tool can be automated at least...

[Neper]

Right, off for a walk along the Kent coast near Dungeness.

I envy you. Certainly an acquired taste but I love the place.

[bd139]

I need to go there again now. Nice photos 

[ch_scr]

Right, off for a walk along the Kent coast near Dungeness.

I envy you. Certainly an acquired taste but I love the place.

That reminds me, is there a good German translation for "acquired taste". Can't think of any 

[Neper]

Etwas für Kenner or, less positive, gewöhnungsbedürftig.

As to my first photo, I'm still looking for an English translation of Während der Fahrt bitte festhalten. Literally: Please hold on during the ride.

[mnementh]

Have you tried FreeCAD?   

This is quite funny. I was having a discussion yesterday with a colleague about software. He got into 3DP recently and tried to use FreeCAD for about a month before giving up. His comment was that it should be put into a skip with LibreOffice, Thunderbird, Gimp and Darktable. Having, through no irony at all, used all of them I had to agree. He uses a mac now as well to quote because “his tears were burning the cuts on his arms after a year on Ubuntu” 

BWAHAHAHAHA!!!

You bastard!!! I literally snorted scrambled eggs out my nose that made me laugh so hard!!!   

mnem
Oh gawrrrd... it burrns... I fucking hate you!!!   

[Specmaster]

I need to go there again now. Nice photos 

Been there, it's a desolate area, very windy and no shelter if the heavens open up, so no thank you.

[Neper]

Give it another chance in better weather. Dungeness definitely has its charm.

[mnementh]

TV REPAIR

Make sure if you are able to resurrect the other strings, that your friend is well aware that he might actually spot areas of his screen that are dimmer than others, in the areas with the dead LEDs, otherwise he might not be happy with you. Short of replacing all the strings, I can see no way around that problem. Great work so far, keep it coming.

Well yes if I manage to fix the thing I will see if the lighting is even enough to be acceptable, i fnot will tell him what he wants to do.

Hopefully there WILL be dark spots and he will tell me OK fuck you can keep it... more spare boards/parts for Vince ! 

We shall see.

I don't know where to buy the strings nor how much that costs. If it's available for this particular TV, and is ridiculously cheap including shipping... like 20 Euros shipped, and given the TV is recent, maybe he will want to pay for that. We are not there yet....

Why the eff would you trash an obviously repairable TV like that? Just put it away and wait for a paycheck so you can buy some LEDs for Ifni's sake. You really should replace those LEDs anyways, even if you are sending it back to the owner. Just jumpering them out is begging for all the others in the string to fail prematurely.

Correct repair, short of replacing them all, would be to measure voltage drop across every LED with them lit up and replace any that read appreciably lower or higher than the average. That would be your best chance to avoid recidivism. You already have a cheap hot-air rework station, right?

mnem
 

These LEDs are driven by an active constant current source. Shorting out one or two does not stress the other LEDs in the string. It does affect the CC driver but probably not enough to reduce it's reliability.

Empirical evidence shows otherwise; I expect it's the startup current or possibly overshoot because of the incorrect number of LEDs vs original design. I'm fully aware that these are driven CC; I explained this to Vince earlier in case he wasn't aware. These are not common LED lighting CC drivers which are designed to handle a "range of LED string lengths" at a fixed drive current; they are application-specific and constantly modulate the drive current to very specific levels dependent upon the video program in order to achieve the multiple illumination zones required for higher "dynamic contrast". I see potential for overshoot, especially if there are other "walking dead" LEDs in the string that still light up but haven't burned out yet.

That's why my advice was to test voltage drop across all of them lit up and replace any that were appreciably higher or lower than the average, if not all at once. Best chance at getting more the original 3-4 years out of the thing.

Cheers,

mnem
 

[bd139]

I need to go there again now. Nice photos 

Been there, it's a desolate area, very windy and no shelter if the heavens open up, so no thank you.

Sounds heavenly to me 

I went there on the actual mini railway years ago. Not since.

[mnementh]

Find an image editing tool with white balance control on it. Click that then click the bit of the picture they’ll at is supposed to be white. Job done. 99% of the photo is the photographer not the camera

med uses Winbloze. Windoze Photos works very well for minor post-processing; that pic, I'd just turn the "WARMTH" and "CLARITY" sliders up a click or three; would make a world of difference. Vince complains about my grey printed knobs being purple too; personally, I suspect the monitor he's using injects a wee bit of bloo.

mnem
 

 

No I don't. IrfanView64.

I am sorry for your loss 

Gee....seems to work OK for my needs. 

Mmmmhmmmm... like my grand-dad usedta say: "I like to beat my knee with a monkey wrench, cuz it feels so good when I stop."

mnem
*toddles off too...*

[Peter_O]

Etwas für Kenner or, less positive, gewöhnungsbedürftig.

As to my first photo, I'm still looking for an English translation of Während der Fahrt bitte festhalten. Literally: Please hold on during the ride.

Please hold on tight while driving please!

One of the rare occurences of "bitte" in german, so please ...   

[mnementh]

TV REPAIR

Make sure if you are able to resurrect the other strings, that your friend is well aware that he might actually spot areas of his screen that are dimmer than others, in the areas with the dead LEDs, otherwise he might not be happy with you. Short of replacing all the strings, I can see no way around that problem. Great work so far, keep it coming.

Well yes if I manage to fix the thing I will see if the lighting is even enough to be acceptable, i fnot will tell him what he wants to do.

Hopefully there WILL be dark spots and he will tell me OK fuck you can keep it... more spare boards/parts for Vince ! 

We shall see.

I don't know where to buy the strings nor how much that costs. If it's available for this particular TV, and is ridiculously cheap including shipping... like 20 Euros shipped, and given the TV is recent, maybe he will want to pay for that. We are not there yet....

Why the eff would you trash an obviously repairable TV like that? Just put it away and wait for a paycheck so you can buy some LEDs for Ifni's sake. You really should replace those LEDs anyways, even if you are sending it back to the owner. Just jumpering them out is begging for all the others in the string to fail prematurely.

Correct repair, short of replacing them all, would be to measure voltage drop across every LED with them lit up and replace any that read appreciably lower or higher than the average. That would be your best chance to avoid recidivism. You already have a cheap hot-air rework station, right?

mnem
 

These LEDs are driven by an active constant current source. Shorting out one or two does not stress the other LEDs in the string. It does affect the CC driver but probably not enough to reduce it's reliability.

Yes and no. There are 4 strings but the driver has only two outputs, so they wired strings in 2 parallel pairs : string 1 and 2, and strings 3 and 4.  So the chip can only regulate the overall current in a pair but has no clue about how the current splits between the two strings in a given pair. So if you remove one LED then there is an imbalance that the chip can't know about nor act upon.
I assume that's what Dragon had in miind...

In my case I am "lucky" in that I have one failed/bridged LED in each string of a pair, so they still have the same number of LEDs each !!! 

Are the strings possibly wired so that the polarity opposes in each pair? This would make for 4 illumination zones.

mnem
 

[Robert763]

Only two power mosfets so unlikley

[Specmaster]

Give it another chance in better weather. Dungeness definitely has its charm.

The last time I was there, was a few years ago, and they had a fleet of dredgers rebuilding the beaches there by dredging the sea bed and pumping it onto the beach to repair the erosion there. The most interesting thing there is the 15" gauge Dymchurch light railway.

[mnementh]

Condolences then. I'd rather drill screws through my feet than ever use that fustercluck again. Only app I ever found less intuitive than EagleCAD. 

mnem
*cringe*

Ah, so you've never used FreeCAD then? 

No... thankfully I was warned away by good folk on a forum similar to this one. Maybe this very one... was it you...? 

mnem
*CRS strikes again*

[mnementh]

Futch. Here we go again...

mnem
 

[mnementh]

Currently, sitting here waiting for the workmen to arrive. We are having the bathroom refitted and were told that they would be with us this morning at 8.00AM, now 8.54AM and still sign of them. The job is supposed to take upto 2 weeks, thinking of taking friendly bets on the completion date 

Before placing any bets: Are the builders (1) Native English  ("Normal for Essex"), (2) Native English, or (3) Polish?

Well they have just arrived and certainly don't sound natives and they are already crashing and banging ripping out the old kit so they may be Polish after all.

This means they'll get all the old shit ripped out, grab their tool bags but leave wheelbarrows and dustbins scattered about, and won't call or show up again until the day before it's due. There may or may not be a huge hole to the outside haphazardly covered with a tarp. When they return they will then be all assholes and elbows for 3-7 days, and if you're lucky, most of the crooked bits will be behind the toilet. Which lid will be left up with a floater for final inspection. 

mnem
And the cat may or may not be pregnant. 50:50 odds there.