Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 1631905 times)

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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7325 on: February 13, 2018, 06:11:21 pm »
Amen to that
Who let Murphy in?
 

Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7326 on: February 13, 2018, 06:36:34 pm »
Oh fook. I think I know where the problem is with that mains PSU. Output voltage is quoted as being NOT +50v but +/-50v.  I have a bad feeling the negative terminal was actually -50v while the postive was +50v. The ground terminal in the middle. So potential difference 100V...  :palm:  Should have read the advert more carefully I think.
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7327 on: February 13, 2018, 06:45:03 pm »
Oh fook. I think I know where the problem is with that mains PSU. Output voltage is quoted as being NOT +50v but +/-50v.  I have a bad feeling the negative terminal was actually -50v while the postive was +50v. The ground terminal in the middle. So potential difference 100V...  :palm:  Should have read the advert more carefully I think.
Oh feck, you're right, is it still working? if so, and your Amazon turns out to be correct then it wont have been an expensive mistake after all?

Edit.

It would make sense seeing as it was designed as a power supply for Hi-Fi amps which would more then likely be push pull outputs with -/+ rails.
« Last Edit: February 13, 2018, 06:47:36 pm by Specmaster »
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7328 on: February 13, 2018, 07:38:20 pm »
Whoops. At least you got a fireworks display in the process :)
 

Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7329 on: February 13, 2018, 08:04:21 pm »
Yes the PSU still works, and yes confirmed -50V on the '-' terminal. I feel so dumb, should have checked.

That damn cap nearly took my head off, I had to stand on steps to reach a spare switched socket on the top shelf, flicked the switch while it was about 24" directly below my face . Must have just missed!
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7330 on: February 13, 2018, 08:07:31 pm »
I had one bounce off my head once when I was a kid. Teaches you a lot of respect for the things.
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7331 on: February 13, 2018, 08:13:07 pm »
I had one bounce off my head once when I was a kid. Teaches you a lot of respect for the things.
And that is the reason for bd139 being the person he is today...........
Who let Murphy in?
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7332 on: February 13, 2018, 08:16:03 pm »
Yes the PSU still works, and yes confirmed -50V on the '-' terminal. I feel so dumb, should have checked.

That damn cap nearly took my head off, I had to stand on steps to reach a spare switched socket on the top shelf, flicked the switch while it was about 24" directly below my face . Must have just missed!
Don't beat yourself over it, I reckon we have done similar things in our time and we all learned so much from them as well, chalk it up to experience.

Keep us updated on the Amazon order and if does what you want it to?
Who let Murphy in?
 

Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7333 on: February 13, 2018, 08:34:18 pm »
Thanks, I will let you know. Had another look at the DPS5015, no other sign of physical damage and the fuses are still good, but -50v on the ground plane probably not healthy for the ICs. I'll try tracing some voltages, not much else to do tonight.
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7334 on: February 13, 2018, 08:43:13 pm »
My 0-12 just stopped displaying a trace. Nothing catastrophic happened and the rear of the CRT still lights up, worked just fine last night.
Exact coarse of events, crt was loose and so it rotated when i moved it.
I open it and very carefully rotated it back.
I take extreme caution and tighten the clamp.
Quick test, still works and is even.
Back in the case it goes and to bed i went.
No trace this morning.  :wtf:

Anyone got any hints or ideas? I hope i didn't screw damage it.

*FIXED*
Don't ask me how but all i did was i yelled, "Work you miserable cur!" at it. ::)
Imagine my surprise when that worked. :-DD
So threatening a good dropping or getting out the hammer is a valid repair method too then  :-DD

"Percussive Maintenance"; an engineering staple since the days of steam, my friend. ;)

Quick T12 update ... this is the bodger's iron set up...  :-DD

MyDel 13.8V 22A power supply -> Chinese boost converter to 24V -> DC T12 -> hacked up 9501 handle wedged in a Weller TCP stand. Works really well although the Chinese boost converter makes some painful screams when it is initially heating up. I think it's the windings on the inductor vibrating. When in use it doesn't scream.

This thing is a joy to work SMD with the K tips.



This is exactly what I'm building for my portable rig, and the same exact Boost Regulator as well. I'm also using its Buck Regulator cousin on my FIRST build, as once rectified the trans brings either 18.5V half-wave or 37V full-wave. I've been running the beast at 18.5V and it heated up in about 20 seconds, but it has recently developed a serious issue in that temp response is very poor, where it was pretty good even at the lower voltage. Used to be I could stab it right into a wet sponge and it just sat there right around 290-295° then climbed back up to 300° after a second or less; now it drops to 180-200° before it starts to come back up. This seems to be so on every tip.



Since I received my 150W Buck reg I've been running it at 28V and it's a lot better, but I need to do the diag work and figure out where the voltage drop is. I had been running it at 28V on a 4A buck reg when I first got it that never seemed to run hot but eventually died; I suspect a resultant "Dead FET Walking" scenario where the series pass transistor in the controller still works but just isn't up to snuff.

Well that was impressive LOL! (see pics). Connected a 48v input to the DPS5015 and a capacitor can hit the ceiling :) Yes, the polarity was correct - at least according to the silk screen on the PCBs - so need to look a bit closer at that. I'll put a new cap in DSP5015 and see if there's any life left in the thing, and this time check what the Chinese '48v PSU' is really putting out before connecting it...

Did you buy it from BANGgood or BangGood?  :-DD
Thats very good  ;D

BG is pretty much a staple anymore in the RC Hobbyist field; like Wal-mart, sooner or later EVERYBODY shops there. ;) They are commonly known as "Bang-BAD", "Bang'emGood", "BunkGoods", and "Banged-UpGoods" plus dozens more similar variants.

I've gotten dozens of bad items from them; some have been quite annoying, but all were eventually resolved to my satisfaction. of course, lately my track record with Wally-World has been similarly abysmal from a sample of a lot fewer purchases.

I received a bunk dual 5W LED bike headlight that I had to go through Customer Support 3 times before it got sorted; first got a visibly used unit with dead LEDs, which after going back & forth with their customer support, they shipped out a replacement... which when it arrived turned out to be a no-name cassette Walkman which shelf wear indicated it had been kicking around a warehouse since cassette Walkmans were a "thing". Eventually I DID get a WORKING unit; but only after 33 eMails and 2 months.

That said... I've probably spent thousands with them on my RC hobby; and even when they ship you bunk, they'll eventually make it right... you just have to be persistent and keep in mind a "kill them with kindness" level of patience when dealing with their customer support. They, along with DealeXtreme.com and Goodluckbuy.com, are about as close to a "China-direct Supermarket" as you're going to get. AliEx is more like a China-direct fleaBay; where every vendor is a crapshoot and you really need to do your homework, or be willing to take a (relatively small) chance on just losing your money.

Oh fook. I think I know where the problem is with that mains PSU. Output voltage is quoted as being NOT +50v but +/-50v.  I have a bad feeling the negative terminal was actually -50v while the postive was +50v. The ground terminal in the middle. So potential difference 100V...  :palm:  Should have read the advert more carefully I think.
Oh feck, you're right, is it still working? if so, and your Amazon turns out to be correct then it wont have been an expensive mistake after all?

Edit.

It would make sense seeing as it was designed as a power supply for Hi-Fi amps which would more then likely be push pull outputs with -/+ rails.

D'OH!!!

I hate to admit it, but I have made the EXACT same stuffup, only it was a LiPo charger I inadvertently hooked up to +36V/0V/-36V linear power supply from an old home theater amp that was very conveniently all on one PCB, with the transformer bolted through. Much hilarity did ensue, and the poor thing shuffled off the mortal coil with great and mighty crackleage, smoke and a pitiful squeal like HAL 9000 imitating Pac-man dying. The linear PSU just went "Ominous HUM-M-M-M-M..."...  :-DD

I had one bounce off my head once when I was a kid. Teaches you a lot of respect for the things.
And that is the reason for bd139 being the person he is today...........

This explains SO-O-O much... ;)


mnem
"Sooo... you don't want to connect to my iPad, eh, Mr. Broadcomm? Sounds like you need a little personal attention... Oh, that's no problem; I have a 'scope handy, and the probes are nice & CO-O-OLD..."
« Last Edit: February 13, 2018, 08:46:34 pm by mnementh »
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7335 on: February 13, 2018, 08:59:56 pm »
I think I lost a few IQ points on that. It was one of the suicide cans of the 1950s in a radio I was repurposing, if I remember to try and extract worms from the ground with the HT transformer. This was about 1985 so it was completely hosed by then. Vents? VENTS? Hahahaha death by electric pipe bomb is all you're having for dinner  :o

Interesting failure mode. I will watch out for failures on mine. So far it seems to just jam itself quite happily at the set temperature and stay there. This is more than I can say for the Weller. Since they introduced those new two part tips, all is not well.
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7336 on: February 13, 2018, 09:12:45 pm »
I've had a couple of the tips where one of the contact rings has decided to unclip itself that I've had to throw in the trash can. Do the genuine Hakko tips have the same issues or are they soldered rings on them?
Who let Murphy in?
 

Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7337 on: February 13, 2018, 10:04:42 pm »
LOL! Just noticed the impact site of the cap case - quite a dent :)
 

Offline beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7338 on: February 13, 2018, 10:16:01 pm »
Reminds me of a Champagne cork incident. My Father opening a bottle back in the 70's popping the cork at a party as you did impacting the florescent tubes (2) right over the dinner table and the food   :palm:

Moral of the story is don't play with power supplies or Chinesium Caps at the dinner table either :-DD
Coffee, Food, R/C and electronics nerd in no particular order :)
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7339 on: February 13, 2018, 10:19:36 pm »
LOL! Just noticed the impact site of the cap case - quite a dent :)
Yep thats a fair impression and given that it was one of the new er vented types, you can imagine the destructive force of the older sealed caps, especially the big old filter caps, they really could do some pretty series damage when they blew. I expect that you'll be extra careful in the future eh  :-+
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Offline Neomys Sapiens

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7340 on: February 13, 2018, 10:20:25 pm »
I had one bounce off my head once when I was a kid. Teaches you a lot of respect for the things.
Uhuh. I was about 15 when I spent my holidays working at a small engineering company specializing in the then nascent PLCs and related stuff. One of my tasks was to build a better 24VDC power supply for the test stand (like the usual, industrial DC, but smoother...)
The companies' office was in a converted flat in a nice housing area, so complete with stucco ceilings.
The power supply had 6 big capacitors, one of which got his polarity misplaced.
They had to live with the ugly brown stain at the ceiling until they moved out.
Whenever I entered the lab during my association with this company, which did last several years, someone would look up.
 

Offline GreyWoolfe

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7341 on: February 13, 2018, 10:22:25 pm »
ChrisXL200, at least some of the cap was still there.  A few years back, I got roped into fixing a bunch of ELO touchscreen monitors that had dodgy rework done to them.  More than once, there was just the legs still soldered into the PCB, nothing else.  Thankfully, they were already blowed up real good before they got to me. :-DD
That which doesn't kill you still requires a co-pay.
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7342 on: February 13, 2018, 10:37:05 pm »
It's fun to just blow them up sometimes though. I bought about a quid's worth from bitsbox here in the UK of cheap ones with no vents and I'll just sit there popping them for fun, or until the wife moans about the smoke. My 5 year old loves doing it too.
 

Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7343 on: February 13, 2018, 11:10:06 pm »
I'm working on the PSU case at the moment, made from 5x5""  x 1/4" wall square tube. Amour plating - the damn Chinese caps can pop all they like inside that.  :-DD
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7344 on: February 13, 2018, 11:21:10 pm »
Wow that is heavy duty stuff, expecting a tank to come bursting through your lab and run over your gear??
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Offline ChrisLX200

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7345 on: February 13, 2018, 11:34:26 pm »
Wow that is heavy duty stuff, expecting a tank to come bursting through your lab and run over your gear??

:) It was all I had in that size, and it's easier working with it than sheet metal - this stuff I can machine on the miller.
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7346 on: February 14, 2018, 12:25:38 am »
Quick T12 update ... this is the bodger's iron set up...  :-DD

MyDel 13.8V 22A power supply -> Chinese boost converter to 24V -> DC T12 -> hacked up 9501 handle wedged in a Weller TCP stand.

At first glance, I thought you built your T12 inside a power supply enclosure. ;D
I TEA.
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7347 on: February 14, 2018, 12:36:07 am »
LOL! Just noticed the impact site of the cap case - quite a dent :)

Oh, my! You really got a souvenir from that. I've had caps fly off before, but this is the first time I've seen them leave an impression on the ceiling.
I TEA.
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7348 on: February 14, 2018, 12:37:25 am »
I'm working on the PSU case at the moment, made from 5x5""  x 1/4" wall square tube. Amour plating - the damn Chinese caps can pop all they like inside that.  :-DD

Uh, yeah. That should be cap-safe now! :-DD
I TEA.
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #7349 on: February 14, 2018, 12:40:53 am »
Thanks, I will let you know. Had another look at the DPS5015, no other sign of physical damage and the fuses are still good, but -50v on the ground plane probably not healthy for the ICs. I'll try tracing some voltages, not much else to do tonight.

Any good news on it? Hopefully, you can revive it with some rework and replacement parts.
I TEA.
 


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