Foreplay 3 amp no output (Paramount)

Rob C · 264894

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Offline Paul Birkeland

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Reply #60 on: October 18, 2021, 02:34:23 PM
If tapping things changes voltage dramatically, you should go through and reflow all of the solder joints in the amp and look for broken wires.  If you'd like to send these in for repair, I do handle legacy repairs and I can get this amp fixed up for you.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #61 on: October 18, 2021, 03:05:48 PM
Cool thanks, gonna reflow first.



Offline Rob C

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Reply #62 on: September 30, 2022, 06:56:51 PM
223 vdc on the green board Transistor



Offline Rob C

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Reply #63 on: September 30, 2022, 07:00:04 PM
250vdc on one Transistor
500 on the other.
Little green board w 4 leds,the Transistor has 223vdc



Offline Rob C

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Reply #64 on: September 30, 2022, 07:09:21 PM
Still getting same issue. I'll check voltages again. Tomorrow with the manual.



Offline Rob C

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Reply #65 on: October 01, 2022, 05:30:22 AM
Voltages.
It's been on for over an hour. If it does fault, as soon as I goto take voltages, it comes on.



Offline Paul Birkeland

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Reply #66 on: October 01, 2022, 05:33:03 AM
If you look at the white printing Q2 on the A side of that PC board, then look at the large blue resistor next to it, you can see a typical solder joint that hasn't flowed out all the way.  You can see the brown flux built up in the middle of the joint around the lead of the resistor, and that kind of joint can cause intermittent issues that seem to resolve themselves as soon as you touch them. 

Having said that, it's also really important not to resolder any of the LED solder joints, as that can damage the LEDs since they have been sitting around absorbing moisture over the last decade or so, and heating them up will boil that moisture right out and blow the LED.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #67 on: October 02, 2022, 03:35:05 PM
Thank you! I do see that.  Just reflowed.
It was playing a few hours today before it went out. When I took it to the bench, even when I went to test voltage on the main board Transistor, it came on. Hope that reflow did it. Cheers!



Offline Rob C

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Reply #68 on: October 05, 2022, 03:00:53 PM
Turned it on today nothing out of one block. When I unplugged it and looked underneath one LED was lit for quite a while after it was unplugged then it went out slowly put it on the bench, came on right away and then was intermittent.  I will attach a video.
 Tested all 20 terminal strips. Voltage is properVariation 10 to 15%



Offline Rob C

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Reply #69 on: October 05, 2022, 03:04:06 PM
I'm also getting 123 to a 124 V out of the wall I don't know if that makes a difference but I when I tested the terminal strips I was using my variac at 1:19 like it says in the manual.



Offline Paul Birkeland

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Reply #70 on: October 05, 2022, 03:11:11 PM
If poking the power supply board is having those effects, there may be a loose part or a bad solder joint on the power supply board (which is a total PITA to remove).

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #71 on: October 05, 2022, 03:49:33 PM
Really pretty much poking anywhere on here brings it back to life but yeah it does look like a pain in the ass to remove



Offline Paul Birkeland

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Reply #72 on: October 05, 2022, 04:27:40 PM
A broken wire would create these kids of issues. If you just barely touch the bad wire with your meter, it should easily set that off.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #73 on: October 06, 2022, 02:36:16 AM
If I barely touch ANYWHERE it will set it off. 1st board, 2nd board, transistors, tabs,.....anything high voltage. Meter touches, brings it back to life.



Offline Paul Birkeland

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Reply #74 on: October 06, 2022, 04:16:32 AM
If I had that amp on my bench, I would poke around to see what was most sensitive or what I could do to make the problem permanent, then take measurements to see what's missing.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man