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my Urie 1176 died, help!
Old 24th January 2021
  #31
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
As I mentioned, I'm having trouble finding someone local to work on it. I decided to replace the power supply caps myself to see if that solves the problem.

I'm going to purchase these from Mouser Electronics unless someone has a better supplier or brand name:

(x3) Vishay 594-MAL212517222E3
Aluminum Electrolytic Capacitors - Axial Leaded 2200UF 40V
https://www.mouser.com/ProductDetail...AL212517222E3/

(x1) CDE 598-108TMA050M
Aluminum Electrolytic Capacitors - Axial Leaded 1000uF 50V 20% tol ELECTROLYTIC
https://www.mouser.com/ProductDetail/598-108TMA050M/
Old 24th January 2021
  #32
I use much larger caps here, radial as those are available. Use a dab of hot glue to support them.
Old 24th January 2021 | Show parent
  #33
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
The radial caps all have the terminals on the same side. I need them on opposite sides of the cap end to fit the board layout
Old 24th January 2021 | Show parent
  #34
Lives for gear
 
3 Reviews written
🎧 5 years
Quote:
Originally Posted by soul. ➡️
The radial caps all have the terminals on the same side. I need them on opposite sides of the cap end to fit the board layout
Honestly soul this is part of why I don’t think you should jump in with this as your first project. Jim is giving you great advice, but you don’t know what to do with it. A recap is a simple job, but your urei has value and it would be a shame to wreck it. If you want to learn, try it out first on something else! I would help you as much as you need/as much as I can for that.

Regarding the measurement of caps for continuity (from our previous exchange), you will never be able to measure continuity from one side of a cap to the the other. Continuity is measuring very low resistance, capacitors don’t have resistance (for our purposes here), they have capacitance m, therefore you should never be able to read continuity through a cap. It’s a very bad sign if you can! When you wrote that not reading continuity from one pin of a cap to the other, it was a red flag for me that I shouldn’t be giving you advise on how to fix or even dig around in this through the internet.

Trust me on this. It’s not to discourage you from learning, but don’t jump into the deep in on this. Buy a kit for something simple, learn as you go, practice desoldering. At the end of the day you are very likely going to need to send this to a good tech anyhow.
Old 24th January 2021 | Show parent
  #35
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Much appreciated, enginefire! I just want it up and running and figure if I just swap out the caps for identical values I wont hurt it. I do know how to solder, but you're right. Thanks again, I'll try to resist and keep searching for a tech

Last edited by soul.; 24th January 2021 at 10:50 PM..
Old 20th March 2021 | Show parent
  #36
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Hi, I'm stubborn and I'm back!

I'm still having trouble finding someone who I trust locally to work on it. The only place is on a 4-6 week backlog before they even look at it. I went to the shop to drop it off, and changed my mind after seeing a store full of electronic stuf from radios to turntables and cheap pa gear. I didn't feel comfortable leaving my rare, valuable 1176 there. SO, here I am again. I'd like to replace the caps myself, I don't see how it can hurt if I replace them with the right parts. I am capable of decent soldering work and just need some help buying the correct parts. Would anyone be willing to help me find them? Thanks in advance
Old 28th March 2021 | Show parent
  #37
Re: Caps with leads on both ends - search for caps with axial leads.
(Axial = leads along the axis, radial = leads along the radius)

Super important whan replacing electrolytic caps:
Make absolutely sure the plus/minus indicators are positioned exactly as the original parts were. If you put any of them in backwards, smoke will come out.
I find it handy to make a quick sketch of the board with the original caps, marking each lead as plus or minus first.

Another tip on replacing electrolytic caps:
Depending on the circuit board design, some boards have internal copper layers for ground and power. These layers siphon heat away when you try to desolder or solder, so you might have the top hole hot enough to melt solder while the bottom hole is still solid. Tugging on the cap in this situation can easily result in permanently damaging the board. So if you find the lead doesn't want to move easily with the joint well heated, this might apply to you.

One workaround is to use separate irons on the top and bottom sides of the board at once, while very gently pulling on the part (with your 3rd hand ) to make sure it's loose.
Another workaround is to heat the board to 150 deg F for twenty miniutes in an electric (*not gas*) oven, before desoldering, in the hopes that if you pull it out of the oven and desolder while it's still hot, that a single iron can raise the temp enough to melt the 'via' hole solder completely.

Good luck!
Old 28th March 2021 | Show parent
  #38
Lives for gear
 
3 Reviews written
🎧 5 years
Quote:
Originally Posted by Philbo King ➡️
Re:
Another workaround is to heat the board to 150 deg F for twenty miniutes in an electric (*not gas*) oven, before desoldering, in the hopes that if you pull it out of the oven and desolder while it's still hot, that a single iron can raise the temp enough to melt the 'via' hole solder completely.

Good luck!
No offense but this is terrible advice. No one should do this. There are much better ways to desolder multilayer pcbs than cooking every component in the circuit.
Old 29th March 2021
  #39
Lives for gear
 
🎧 15 years
Agree about the terrible advice. None of the UREI 1176LN revisions used multiple layer PCB's. I've never seen a tech use 2 soldering irons to replace a part (ridiculous) and anyway, those capacitors aren't hard to remove.

Your unit is probably due for a recap, but I doubt that will resolve the dead audio problem, especially if something smells burned inside.
Old 29th March 2021 | Show parent
  #40
I used to do it routinely when I worked as an electronics tech at an aerospace company. These were often 12 to 24 layer boards intended fir use in avionics such as autopilots. 150F is well below the damage threshhold, even for consumer grade parts. But I offered the advice, knowing it would probably be overkill for this unit.
Old 29th March 2021 | Show parent
  #41
Lives for gear
 
🎧 15 years
150F would probably damage the plastic case and cover of the VU meter. The VU lamps alone will do that over time. And it's about 35 degrees under the rating of the capacitors in the unit, but I wouldn't subject old ones to that much heat. The components in this unit are not avionics grade.

Philbo King, I'd save the oven for baking brownies, which, depending on the ingredients, should probably be done after a repair is finished.
Old 4 weeks ago
  #42
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
I want to send a massive shout-out to Bryan M for diagnosing and determining the cause of the issue was a single $10 part that needed replacement.

It was an easy fix with his brilliant help and expertise. He knew all the values by heart and found the problem within 3 steps, while I followed his instructions

Thanks to enginefire, cathode, rob, philbo, david, jim, and everyone else for chiming in. Yes, those caps should be replaced, but they are working for now. 1176 is back up and running.

Enjoy the rest of the weekend!

Last edited by soul.; 3 weeks ago at 05:02 PM..
Old 4 weeks ago | Show parent
  #43
Lives for gear
 
SP2016's Avatar
 
🎧 10 years
For everybody following this thread it would be very interesting not knowing what it has cost you, but what part(s) needed replacement.
Old 3 weeks ago | Show parent
  #44
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Quote:
Originally Posted by SP2016 ➡️
For everybody following this thread it would be very interesting not knowing what it has cost you, but what part(s) needed replacement.
regulator = the thing next to the big caps with the spinny-fan heat-sink on top
Old 3 weeks ago
  #45
Lives for gear
 
3 Reviews written
🎧 5 years
Awesome, I’m so glad you ended up finding someone who could troubleshoot it for you!
Old 3 weeks ago | Show parent
  #46
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Quote:
Originally Posted by enginefire ➡️
Awesome, I’m so glad you ended up finding someone who could troubleshoot it for you!
thanks for your help!
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