> From: conor.strachan@...
>
> The amount of noise coming of the output with the crackling
> It doesn't make me think it's a power thing coming from somewhere.
>
> 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.

Yes, it's R4. I misread the schematic.

> 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.

Sounds good.

> 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'm sure the regulators are okay, or they'd be putting out a much higher voltage or zero.

> 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..

Well, all it takes is one bit to finally drift across the threshold, turning one machine instruction into another one and causing a crash.

> I could clean out the RAM and processor sockets, i can't see
> how to get the metal shield off that processed though.

You slide it to the right. It's very snug. If you want to remove the RAMs, you'll have to unplug the battery first, and then redo all the calibrations when it's all back together.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...