Foreplay 3 amp no output (Paramount)

Rob C · 264893

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Offline Rob C

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Reply #75 on: October 07, 2022, 05:02:37 AM
When I poke around with a wooden paintbrush on everything nothing changes as soon as I use any piece of metal whether it's needle nose or a screwdriver that's when it comes back to life



Offline Rob C

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Reply #76 on: October 07, 2022, 08:48:18 AM
I reflowed the 2n2907 .  one LED's does not light anymore  but I'm not getting the speaker ticking like I was before using the probe. Audio but no treble
« Last Edit: October 07, 2022, 09:36:48 AM by Rob Capizzi »



Offline Rob C

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Reply #77 on: October 07, 2022, 09:01:46 AM
1. 445dc
5. 64dc
6. 64dc
7. 200dc
9.  270dc
11. 200dc
12 128dc
14. 57dc
15 1.2dc
16. 465dc
19. 275



Offline Rob C

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Reply #78 on: October 07, 2022, 09:31:32 AM
One LED out, no treble,  290vdc to b1 on 9 pin socket. Should be 195ish. Other 8 pins read fine.   Touched terminal 11 all leds lit and treble came back, touched another terminal went dark again.
« Last Edit: October 07, 2022, 09:36:04 AM by Rob Capizzi »



Offline Paul Birkeland

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Reply #79 on: October 07, 2022, 10:05:10 AM
You have a loose or broken wire.  I wouldn't bother reflowing a transistor on the C4S board when you can poke the power supply board and cause things to drop out.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #80 on: October 07, 2022, 10:33:29 AM
Needle nose twist on that transistor brings to life. I reflowed a few times. . It's on.      Nervous to touch anything. I've been staring at this for hours can't find loose wires.



Offline Rob C

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Reply #81 on: October 07, 2022, 10:45:57 AM
Poking on power supply board does not drop it out anymore I'm sending a video of me slightly twisting the transistor on the shunt board. I totally hear you and I agree on the wire. I just cannot find one and I've reflowed a lot on here and I'm feeling it's the transistor.



Offline Rob C

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Reply #82 on: October 07, 2022, 10:47:04 AM
I could assure you that it's only doing that when I twist that transistor not the board I could flip that board around and move it and tweak it and nothing happens. only when I twist that transistor



Offline Rob C

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Reply #83 on: October 07, 2022, 11:03:58 AM
Listening to music now. it will drop out after a few minutes but then come right back without touching anything.



Offline Rob C

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Reply #84 on: October 07, 2022, 11:21:13 AM
Is replacing the Transistor a bad idea? I'm kinda leaning toward that.  It seems like that's where the problem is stemming from.  When the amp is good I'm seriously tugging on all the wired connections and I can't replicate it unless I turn that transistor or does it by itself



Offline Paul Birkeland

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Reply #85 on: October 07, 2022, 02:53:33 PM
Go for it, you may find a broken wire when you remove that PC board ;)

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Rob C

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Reply #86 on: October 07, 2022, 03:44:37 PM
I get it. I wish i could find said broken wire. C4s. That board has been up for a while. She's been holding steady for an hour plus so far. Reflowing n2n907 seems to been showing the best results. That transistor seems to have the most sensitivity. 



Offline 2wo

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Reply #87 on: October 07, 2022, 04:50:18 PM
Is it possible you have a damaged trace? Check for a crack in the vicinity of that transistor, right were it forms the eyelets ...John

John S.


Offline Rob C

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Reply #88 on: October 08, 2022, 07:15:36 AM
Kinda seems like it. She's holding pretty steady as of now since reflow.



Offline Rob C

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Reply #89 on: October 17, 2022, 01:15:22 PM
I can't see if any cracks by trace. Too small. I replaced the Transistor 2n2907a,  it plays longer, cuts out a few seconds then comes back on for a while, the twisting of Transistor isn't cutting in and out like previous video. So I'd say it's a little better, but not fixed. I can't get it to cut out manually. I moved every wire and can't replicate it. It will cut out by its self, when I touch certain metal parts, with a metallic probe,like the Transistor I can hear static clicking in speakers like some sort of discharge. I go to sleep thinking what it could be. When it cuts out the d2 led on the b side remains lit.