I would suspect the actual RAM chip has gone bad. It is IC32. I've had
to replace the RAM chip on more than one rebuilt KLM-367 board.
It is listed as a Toshiba TC5514-APL3, but there are a few equivalent
part numbers that drop-in as well. In the USA, I get them from
www.jameco.com, Jameco stock# 43238. The part they sell is an Intersil
HM6514, but it works just fine as a direct replacement.
See
http://www.jameco.com/Jameco/Products/ProdDS/43238.pdf These also replace the hard-to-obtain Nec uPD444c (same sort of RAM
chip).
It is also possible that the RAM addressing latches, IC24 and IC26, are
bad or otherwise a trace involving them is corroded.
Crow
/∗∗/
On Thu, 5 Dec 2002, reidar_oz wrote:
> I bought my PolySix a few months ago and had to have the battery and
> IC31 replaced and a few tracks re-wired. It now sounds fantastic, but
> there are a couple of problems.
>
> First, when I turn it on, there is no sound available except a very
> low-frequency 'bloop'. I have to press the 'Manual' button and twiddle a
> few knobs to start getting a proper sound. Is this normal? I would
> have thought it would have some recognisable patch on power-up.
>
> Also, the write-to-memory doesn't work well. If I write a patch, then
> select another patch, then back to the new patch, the sound is nothing
> like what I thought I stored. Presumably there is another chip
> somewhere that needs to be replaced. Is this a common problem with an
> easy fix?