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Let's Get Technical => Troubleshooting Problems => Topic started by: bunkyloo on September 28, 2018, 05:52:08 PM

Title: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on September 28, 2018, 05:52:08 PM
Just got this on Ebay DOA sound on ss only. The mod was a mess anyways since everything is so sloppy Im not sure where to start the tubes heat up lol and yes ive tried other tubes. thanks steve
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: Systematic Chaos on September 29, 2018, 07:42:13 PM
Pics/gut shots?
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on September 29, 2018, 08:38:57 PM
I will Put some up tomorrow SC. Any Clues would be great!
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: Kim on September 30, 2018, 06:37:52 AM
Before seeing a pic and already knowing that tubes do glow, I'd first make sure all the connections between the tubeboard and motherboard are good before moving on to the tubeboard itself.  Mods/repairs to the tubeboard generally require the tubeboard to be completely removed from the unit.  Maybe something got overlooked and half-assed during reinstallation...

And if "everything is sloppy"  might be good idea to start over, or get another professionally-done tubeboard from MJMP.
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on September 30, 2018, 09:12:10 AM
  Well I believe the tube board was purchased it looks ok its the connections on the main board its self some of the pads/ trace have been damaged and jumpers installed.
The person who sold it to me swears it was working so I think its a bad connection somewhere in that trace I guess could start with the mod schematic btw this a believe was the mjmp tube board theres depot stickers on it and the m3 on the front.
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on September 30, 2018, 01:35:56 PM
some pics
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: Systematic Chaos on September 30, 2018, 06:42:05 PM
The tubeboard looks like an original one. MJMPs new tubeboards have Belton Micalex tube sockets and Metal Film resistors, Orange Drop (IIRC) and Panasonic Caps. This one has the old tubesockets and Carbon Comp resistors
The culprit seems to be in that lifted traces/jumper wired section directly after the input. The Mod3 only affects parts on the tubeboard.
Also, looks like a lot of ICs were replaced.
Can you see/check if its been noise-modded?
U4 seems to have been replaced but it doesn't look like a BB 2604.
How about the PSU filter Caps?

I have a stock V2 than I can pull open and get you some gut shots of that "tampered with" areas so you get some close-ups of how it's supposed to be looking. Iĺl probably get around to doing that next weekend....
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: MarshallJMP on October 01, 2018, 09:32:21 AM
Like Sc said, this is not something from me, nor did I do this work on it.But I think I found the problem, there is a loose solder pad on the bottom side.This one supplies voltage to the heaters. Could be your problem maybe.
See pic.
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on October 01, 2018, 12:04:23 PM
Good eye mjmp I would have never seen that on that picture . I will check it out and yeah I thought he may have gotten a board from you that's only because I misunderstood what mod he attempted and I never thought the soldering was done by you of course. He was just vague on the history.
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: bunkyloo on October 03, 2018, 05:20:58 PM
Well Im still working on it. I really want to repair the traces and re do everything that was done and also there are a couple areas that look questionable. So maybe I should start there haha ( a good deal on ebay ) lol.
Title: Re: Mp-1 v2 mod 3 no output in tube anything
Post by: rnolan on October 05, 2018, 02:16:17 AM
Hey Steve, good luck with it and we'll all help as/where we can  :wave: if you need it.  We don't call it evil bay for no reason LoL.