3 Aug
2014
3 Aug
'14
9:26 a.m.
On Aug 3, 2014, at 09:09 , Chuck Guzis <cclist at sydex.com> wrote:
I don't much care for the 848s either. One aspect
is that the drive spindle motor itself is 24V, but the positioner is 12V. There's a
somewhat over-taxed LM7812 to drop the voltage accordingly, which often fails--that must
have been known, because there's a fuse in series with it.
I had a TM-848 (an earlier belt-drive one) in my TRS-80 Model 12 that shorted the 24V
supply. That LM7812 was the first thing that I suspected, but the problem turned out to be
a shorted filter capacitor right before it.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/