Archive of the former Yahoo!Groups mailing list: Vintage Simmons Drums (UK) Users Group

The battery as fitted to the SDS7 does indeed leak - mine was one of the infamous nicads similar to the ones in the Korg Polysix. A quick google around for Polysixes will reveal the mayhem that leaky nicads can cause - and owners of Cheetah gear will know what I'm talking about too ;-)

Chances are that the EPROM socket has copped a load of acid, although it does creep under the PCB lacquer and dissolve the tracks from below. About the only way to repair it is to scrape away the damaged copper and bridge the tracks with fine wire - a fiddly, horrible job. If the EPROM socket has been gunged it will need replaced; good thing too, they're crap beyond measure. Whip it out (cut it apart and carefully desolder the pins individually with braid and tweezers, to avoid damaging the PCB) and stick in a good-quality turned-pin socket. If the EPROM legs have been dissolved, you can burn another one but 2732 EPROMs are thin on the ground. You may need to use a 2764 and make up a bodge socket to get it to fit.

As for the MTM that only powers up after twelve hours, you need the power supply rebuilt. Check for dry joints on the PSU board particularly around the regulators, failing rectifiers, failing 78xx TO-220 package regulators and failing electrolytics, in that order.

Gordon 2M0YEQ