PC602 help/schematic [message #28703] |
Mon, 25 July 2022 13:33 |
claussoegaard
Messages: 27 Registered: July 2022
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Junior Member |
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Hi all - first post! I tried searching the forum a bit first, but couldn't find exactly what I was looking for, so making my first post.
Short version
I am hoping someone has a PC602 negative regulator board schematic. For now I am drawing one myself from photos of the front/back of the board. But that assumes the components and wiring is already correct, so would love to see an actual schematic to have a "source of truth". For what it's worth it looks 100% original, all the solder joints and components look untouched. But still.
Longer version
I am working on diagnosing a noisy channel on my K200A-2. First I isolated the noise (white noise/static type, not 60 cycle hum type, noise doesn't have a "pitch" to it) to be coming from the reverb/trem/vib boards (PC302A/B). After tons of diagnosing (that I won't write a novel about just yet), I think I've narrowed the issue down to be from "dirty" power.
The PC302A/B board gets +23v from the PC502 board (+regulator) and -23v from the PC602 board (-regulator). It then steps down the +23v to +13v, so in total it's running on a combination of +23v, +13v and -23v. Checking those voltages, the +23v reads just fine on the scope, but both the +13v and the -23v have issues. First off all they both have a ton of noise on them that I can see on the scope, and secondly the -23v line actually reads around -42v!
So - while I'm still not 100% sure this is actually where my noise issue is coming from, I'd like to fix the noisy "-23v" (actual -42v), which is coming from the PC602 board. So, long story short, to help me out with that, a PC602 schematic would be mighty handy.
Thanks in advance for any help! This forum seems amazing!
Cheers,
Claus
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