Subject: RE: Polaris Later version Secondary board
From: conor.strachan@...
Date: 2018-07-13
Hi Paul
Thanks for your reply.
The amount of noise coming off the output with the crackling It does make me think it's a power thing coming.
Do you mean the VR at R4 on the secondary board. On my board the R3 is not tweakable it's only R4 and R15 that have trimmers.
First thing I will do after that is change the caps, as it's easy to do and start with the one that looks a bit corroded for sure.
A friend of mine was saying it might be the Z2 5v regulator as he said it's happen to him on few synths before but I believe on the board it is a 12v regulator and not a 5v there is a LM340 on the schemes but inside mine at Z2 is a LM7812ct which I believe is 12v. That might be worth a try if the caps are not the problem.
I would need to get hold of an EPROM programmer to redo them which I can do, but this just happened pretty much overnight so it wasn't like it was a slow decrease in functionality..
I could clean out the RAM and processor sockets, i can't see how to get the metal shield off that processor though.
Thanks for your help Polaris People