Yahoo Groups archive

Vintage Simmons Drums (UK) Users Group

Index last updated: 2026-04-28 23:14 UTC

Thread

SDS-V switch circuit

SDS-V switch circuit

2013-07-31 by jesper

Hi list,

I've finally dug into my SDS-V (hihat) card that was a bit temperamental 
in that, that all channel LEDs was lit upon startup and that it 
sometimes also played a mix of all settings between channels.
With time (heating) it returned to normalt and functioned as expected.

After tips from Micha I've taken a closer look and decided to change the 
three ICs responsible for the switching. Yesterday I realised I'd forgot 
to order one of them (4556). *crap* But now two are replaced and it's no 
longer a christmas tree. Instead only channel 1 lights up and only 
channel 1 can be chosen.

I'd get to the third IC soon too, but want to ask a Q first...

When desoldering IC1 I found PCB traces below the IC. They looked intact 
but on one of the IC legs there looked to be a solder bridge/post design 
modification, that came loose with the IC. I'll check the schematics to 
verify soon but wanted to see if anyone here has an unpopulated card or 
a picture of one and/or has the faintest idea of what I'm talking about.

*unsure if this made any sense whatsoever* :S

-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.