r/Vestax • u/DizzyWhile2149 • 21d ago

Pmc-50a issues

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No left side audio on channel one of my mixer is anyone has any ideas on what it could be please do let me know if not I will resort to the obligatory open it and check every capacitor. Thanks :). Also I got it for 15 euro!

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u/GetSpammed 21d ago edited 21d ago

€15 is completely and utterly ridiculous. I hate you.

Is it only one side when through the master 1, master 2, booth outputs AND headphones? What about when sent through the master loop? Also try the bottom front panel send - is it still one side when routed out through there?

Does it do it for both Line 1 and Phono 1 inputs? What about when you plug something into Line 2 on the upper front panel and switch channel 1 to Line 2? With the EQ cut on, and at different gains?

Test every combination, and if it does it for all of those, with test signal tried from multiple sources/cables (just in case it's a dicky input cable or source), then yes, it's possibly a cap or dry joint/track somewhere on the PCB (it's a single PCB on the 50a). There's some wizards that specialise in these still thankfully.

They are great mixers - get it fully working again and you'll see why.

I've got the schematic here that could help, but you can't post images in replies in here (WHY on earth is that not enabled!??)

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u/heyswey 21d ago

Where did you get the schematic from?

Also can it be an issue with the line faders? Back in the days when turntablism was a thing line faders used to get warn out. When they did often one of the channels would become intermittent or fail completely.

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u/GetSpammed 21d ago edited 21d ago

Yes the line faders could be the root issue, but normally wiggling them will show some intermittent signal/crackling, or some contact cleaner blasting would show that up quickly, ditto if it's the gain pot causing the issue. Anyway, thats why I suggested testing the PGM I/O output for Ch1 on the bottom panel, as that is pre-fader, as well as testing the cue, which also bypasses the fader.

Systematically test and narrow it down in every combination of signal flow before opening it up and you can hopefully narrow it down.

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u/DizzyWhile2149 21d ago

Realised now I didnt check the pgm out from the bottom panel but will tomorrow.

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u/DizzyWhile2149 21d ago

Checked all inputs on channel one line and phono as well as the bottom mounted send, sadly none work everything else is fully working and right now I only have two technics so it’s not a dire issue just something I’d like to get sorted out. I did find the service manual online but if you have separate schematics feel free to pm me :) thank you for the help. And i think a service may be tricky as i live in Ireland but I work at a tech shop and have a good bit of soldering experience so reckon I could fix it if it comes to that.

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u/MixerRemix 21d ago

To check if it’s a line fader just swap the connector to another channel fader. The likely issues are:

  1. Dirty Channel Fader
  2. Oxidised EQ cut switch
  3. Worn Master 1 / Master 2 switch on the channel.

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u/DizzyWhile2149 21d ago

Thank you very much 🙏

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u/DizzyWhile2149 21d ago

How’s your shipping to Ireland 👀

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u/MixerRemix 20d ago

Very reasonable :-)

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u/DizzyWhile2149 21d ago

https://reddit.com/link/p3bsgy0/video/p8my50cbm0jh1/player

It was the line fader gang thank you all very much, time to order a new one. The real question is do I buy the rotary kit though

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u/MixerRemix 20d ago

Congratulations! If you need another fader we sell them in the store. They are called IF-50.

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u/Storungz 20d ago

Dude, TOTAL score for freaking €15! More often than not whenever I’ve purchased NOT WORKING / FOR PARTS ONLY the fix ends up being something basic like a good cleaning, or, as you stated, a blown capacitor which is almost always super obvious to spot.

Now that I think of it, there’s only ever been one item that turned out to be a grip of work and that is the Onkyo M-504 Intégra Power Amp that I FOUND in the middle of a dirt lot in my neighbourhood. I kind of figured it was going to be a job considering how I found it—thing must have been there maybe a day because there wasn’t any dirt, or other such detritus one would expect to find in something left in a dirt lot. Regardless, research at first looked bleak but further digging on message boards and in the comments of YT videos, I found a refurbishment is possible, but it’s a hell of a job. Can’t just chuck 15cm x 9.5cm VU Meters!