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my Urie 1176 died, help!
Old 31st December 2020
  #1
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
my Urie 1176 died, help!

Happy new year, Gearslutz!

I need some help with my 1176 that stopped passing signal recently. I have confirmed it powers up, the fuse is good, there is some heat inside, and something smells burnt when I opened it!! I can't see anything obvious. I am not all that familiar with the components. Do you see anything that looks suspect? Or that is typical culprit?

Thanks for any advice! Here is a PHOTO of the inside...

https://drive.google.com/file/d/1q9a...ew?usp=sharing
Old 1st January 2021
  #2
Lives for gear
 
3 Reviews written
🎧 5 years
Start by checking the power supply. Are you getting +/- volts as expected? Check out the manual, the schematic, it is helpful. It’s probably +/-15 volts dc but I can’t remember offhand. The psu caps are definitely original and probably need changing.
Old 1st January 2021
  #3
Gear Guru
 
Thomas W. Bethe's Avatar
 
1 Review written
🎧 15 years
All the electrolytic caps look like might need to be replaced. I would do as enginefire suggested and start with the power supply to made sure you have the proper voltages. A beautiful piece of equipment and to not have it working must be very frustrating. Best of luck! Lots of info on this unit on the WWW.
Old 1st January 2021 | Show parent
  #4
Gear Head
 
rob f's Avatar
 
🎧 10 years
Quote:
Originally Posted by enginefire ➡️
Start by checking the power supply. Are you getting +/- volts as expected? Check out the manual, the schematic, it is helpful. It’s probably +/-15 volts dc but I can’t remember offhand. The psu caps are definitely original and probably need changing.

No, it's +30v & -10v.
Old 2nd January 2021 | Show parent
  #5
Lives for gear
 
3 Reviews written
🎧 5 years
Quote:
Originally Posted by rob f ➡️
No, it's +30v & -10v.
Oh of course, there are no spider bugs it this :D
Old 2nd January 2021 | Show parent
  #6
Gear Head
 
rob f's Avatar
 
🎧 10 years
Quote:
Originally Posted by enginefire ➡️
Oh of course, there are no spider bugs it this :D
It's still +30v & -10v in the spider bug versions. The spider bug is hung across 0v & +30v.
Old 2nd January 2021
  #7
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Thanks guys!

I would say you lost me at spider eggs, I'm a noob at this, Ive had the unit for 20 years but this is the first time I've opened it. I have a voltmeter, but not sure where to put it to test voltage. Also I think the caps for the ps are the 4 in the middle back, but not sure.... I'd like to change as little as possible. To begin, can you tell me where I should check voltage? big thanks! Steve

EDIT: Turns out my voltmeter doesn't work, going to buy a new one now...

Last edited by soul.; 3rd January 2021 at 12:56 AM.. Reason: add update
Old 3rd January 2021
  #8
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
UPDATE: I got a new multi-meter. Looks like first cap is reading 60 and the other 3 are reading 0 (if I'm doing this right). Should both pairs read 30 and 0 as mentioned above?

Also, can anyone identify the fuse? Its dead. I was able to use another fuse to test the cap voltages

See images here: https://drive.google.com/drive/folde...T8?usp=sharing
Old 3rd January 2021
  #9
Lives for gear
 
3 Reviews written
🎧 5 years
If your original fuse is dead, that would stop it from working. But why did it die?

Start with identifying which version you have (they are lettered I think, as in rev A, to Rev F or G). Then find the schematic. Working with the schematic is the way to go 100%

Keep in mind that I’d your experience is very low, really troubleshooting and fixing this might be a bit beyond your level, esp considering it’s a nice piece of gear and not some piece of scrap that’s easily replaced.
Old 3rd January 2021
  #10
Gear Head
 
rob f's Avatar
 
🎧 10 years
I understand "the change as little as possible" mentaility, but the electrolytic caps in this unit will be 40+ years old & they should be considered as consumables. As they age the unit will start to lose bass response. Put another way if you had a vintage car would you still have the original oil & tyres in it ? It is possible to measure the electrolytic cap functionailty with an ESR meter but it is quite normal to do a wholesale change when they are this old.
Old 3rd January 2021
  #11
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
rob f/engine fire, both points taken... thanks!!

I'll change out the electrolytic caps (all 4?) any recommendations? The ones I see for sale online have the leads on the same side as opposed to these which are on each side

I'm not sure why the fuse blew, I'm guessing on a rough power-up, or there have been a couple of surges this year... could have been that.

I know how to solder and have repaired a lot of electronics in past, not that I understand how they work, just able to hunt down the bad components (with help). fingers crossed
Old 3rd January 2021 | Show parent
  #12
Gear Head
 
rob f's Avatar
 
🎧 10 years
I would test the PSU rail with your meter before doing anything. Meter set to d.c volts, black probe on an earth/0v point red probe to points need to be tested. You should have a +30v test point & a -10v test point. if you can't measure the right volts there within say 5% then anything else you do will be pretty meaningless until you have that sorted out.

There a many more electrolytics that just those 4 PSU caps. In a nutshell al the caps that look like a smaller version of thise 4 big caps & there is one blue one that is near the input transformer. The type with both leads at one end are called radials. You need the axial type which have a single lead at either end.

There are also 2 tantalum bead caps which are small blue caps in your pic and are near the zener diode with the orange lead going into the top of it with the heatsink on it. They are prone to going short, but you could test for that by putting your meter into it's continuity setting & putting the probes across it.
Old 3rd January 2021 | Show parent
  #13
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
thanks Rob!! that's super-helpful. I'm in learning mode.... on the hunt for parts and I'll test PSU today as you instructed
Old 3rd January 2021 | Show parent
  #14
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Quote:
Originally Posted by rob f ➡️
I would test the PSU rail with your meter before doing anything. Meter set to d.c volts, black probe on an earth/0v point red probe to points need to be tested. You should have a +30v test point & a -10v test point. if you can't measure the right volts there within say 5% then anything else you do will be pretty meaningless until you have that sorted out.
it.
Rob, I tested as you suggested. Looks like I have +30 and -10 (If I did it correctly). Please see new photos, let me know if that looks right. Thanks!
https://drive.google.com/drive/folde...T8?usp=sharing
Old 3rd January 2021
  #15
Gear Guru
Feed it a signal. Then trace it down the audio path until it stops.

Bench repair 101.
Old 3rd January 2021
  #16
Gear Head
 
rob f's Avatar
 
🎧 10 years
I can see the 30v reading but since you are using an analog meter you will need to use the red probe on ground/0v and the black on the -10v test point to measure it.
Old 3rd January 2021
  #17
Lives for gear
 
🎧 15 years
UREI 1176 troubleshooting

your 1176 appears to be an "F".

Take Jim's advice. use a scope,
or a signal tracer which you can make by cutting a guitar cord,
ground the shield with a clip lead, the inside conductor is your probe.

capacitors:
could be, seldom the problem in 1176's with NO signal.
Old 3rd January 2021
  #18
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Thanks all!
Jim, Cathode - I'll figure out how to send a signal to it. I don't have a scope.

Rob - I tried again with the red on the ground. It looks like I get +20 on the cap in the back now... see pic https://drive.google.com/file/d/1Fai...ew?usp=sharing

EDIT: FYI the power transformer smells like its burning.
Old 3rd January 2021
  #19
Lives for gear
 
3 Reviews written
🎧 5 years
Bad power transformer would def blow a fuse.
Set your meter to AC and you should be able to use it to trance signal rudimentarily.
Old 3rd January 2021 | Show parent
  #20
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Its powered up now and the new fuse is holding. I'm not sure how to trace signal, I have another voltmeter that emits a tone whenever circuit is closed. I can put the red/black probes up to each component and signal flow through, athough one of the caps does not let signal pass (cap1 in photos). Im guessing this might be culprit?

Last edited by soul.; 4th January 2021 at 02:04 AM..
Old 4th January 2021 | Show parent
  #21
Lives for gear
 
3 Reviews written
🎧 5 years
No don’t do this
Where is cap 1 in the circuit? What is it doing? If it’s power supply it never sees signal.

Inject an audio signal by patching a sound source into the input of the unit. Try your computer, maybe use a sine wave. 1k is often a good choice.

Before you connect the signal from your computer output to the input of the urei, learn to read the sine wave on your meter. Set it to AC, low voltage. Read when it’s present, then stop it on the computer to read it when it’s gone. Do this a few times to calibrate yourself. Then connect it to the input of your urei.

Keep in mind that if you are poking around in there with the thing plugged in and on you run the risk of killing yourself. Also you could make your urei worse by shorting something out. You could in fact do both at the same time...

Start with your schematic. Do you have it? Learn to read it. Learn to trace the audio path on the schematic so you know where you are expecting to see signal. Post the schematic, people here and recommend good test points. This will help you isolate where the problem is.
Old 4th January 2021 | Show parent
  #22
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Thanks for the advice and warning! Do you sense I'm ready to hurt myself or the unit? LOL I'll read through this tonight after work and try to trace the audio path. I am able to run signal through a small synth. I'll have to learn how to measure it (familiarize myself with it).

On the other hand, I'm now wondering if its the power transformer itself that is the problem? That is the part that smells like it's burning.
Old 4th January 2021 | Show parent
  #23
Lives for gear
 
3 Reviews written
🎧 5 years
Having some bench equipment is very handy. In this case, a known good power source would allow you to bypass the units power supply and test your theory.
Old 9th January 2021
  #24
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
Enginefire thanks for the guidance. I'm going to attempt to trace the audio signal today. I've got a signal generator (iPhone) and cable to the Urie input.

I'm not sure where to put the probe's common. Is it on a ground location? Of course, I don't want to blow anything else on the unit or get shocked

Here's a schematic I found. I would love some help identifying points to test.
Attached Thumbnails
my Urie 1176 died, help!-1176-f-schematic.jpg  
Old 9th January 2021
  #25
Lives for gear
 
3 Reviews written
🎧 5 years
Hey Soul
I don’t think you have the right schematic. You posted a rev F schematic, which has an op amp right after the input (these are the spider bugs we were joking about earlier, because they often have 8 legs).

The picture you posted at the start doesn’t seem to have any op amps. Best to start with the right schematic! Find your right revision letter and then search that schematic.

You should probably start by familiarizing yourself with the schematic and the unit. Do this with the power off. Learn to trace using resistance. From eg from the input to the first component, you should be able to read very low resistance, like 0.5 - 2 ohms ish. This will let you get to know your way around the board and be much safer than do this with the power on trying to trace signal.
Old 9th January 2021 | Show parent
  #26
Lives for gear
 
🎧 15 years
1176 schematic

Quote:
Originally Posted by soul. ➡️
Here's a schematic I found. I would love some help identifying points to test.
soulman,
the schematic you posted is a "K", the last the series from UREI; it is not an "F".
you need to take that unit to a competent tech, otherwise you or the unit are apt to get hurt.
Attached Files
File Type: pdf 1176_f.pdf (244.1 KB, 5 views)
Old 9th January 2021
  #27
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
enginefire, cathode - thnks!!

Now you know I'm not qualified, but you don't know how stubborn I can be I'll move carefully as enginefire suggests and become familiar b4 attempting anything...

All of your guidance is much appreciated. It takes me a bit to understand some of it, but it will sync in and I'll figure it out

Any other advice is welcomed please feel free to comment

EDIT: the image of schematic was listed as rev F from masonaudio.com guess I should have looked closer..
Attached Thumbnails
my Urie 1176 died, help!-screen-shot-2021-01-09-3.09.22-pm.png  

Last edited by soul.; 9th January 2021 at 09:11 PM.. Reason: add photo
Old 10th January 2021
  #28
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
I'm not doing anything yet (actually cant use my iphone to play tone becuase adapter is at work, I'll get it tomorrow)

But in the meantime...

I set my multimeter to the setting that beeps when there is continuity. Most components I have tested seem to beep,k but these capacitors in the power supply do not make any sound.

I believe these are the caps that you guys initially suggested might be the prob
Attached Thumbnails
my Urie 1176 died, help!-urie-1.jpg  
Old 10th January 2021
  #29
Lives for gear
 
3 Reviews written
🎧 5 years
Soul I don’t think you are ready. Cathode is right, take this to a good tech, it’s a valuable piece of gear and there is a high likelihood of self injury in what you are suggesting as your goal.

Start simpler. Start on something that isn’t valuable. Guitar pedals are great because of the low voltage and batteries.

I’m not trying to discourage you, but you really seem to be starting at square one. Not the place to start, don’t learn this stuff on your urei.
Old 10th January 2021 | Show parent
  #30
Gear Maniac
 
soul.'s Avatar
 
🎧 10 years
And with that.... I heed your warnings (enginefire and cathode_ :-)

I've put the top back on and called up some local audio techs. Thanks so much for the guidance, advice and ultimately saving me from probably making it worse...
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