Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!tut.cis.ohio-state.edu!att!cbnewsc!carus
From: carus@cbnewsc.ATT.COM (bryce.w.carus)
Newsgroups: comp.sys.cbm
Subject: Re: 1541 problem
Summary: 1541...try this
Message-ID: <1060@cbnewsc.ATT.COM>
Date: 31 May 89 11:42:06 GMT
References: <11793@s.ms.uky.edu> <2700@csd4.milw.wisc.edu>
Organization: AT&T Bell Laboratories
Lines: 25

> In comp.sys.cbm article <11793@s.ms.uky.edu>, simon@ms.uky.edu (G. Simon Gales) wrote:
> ]The 1541 I gave my sister has died.  When powered up, the drive spins,
> ]the red error light comes on (not flashing), and it just sits there.  The
> ]motor keeps spinning, the light stays lit....etc....etc.
> 
In article <2700@csd4.milw.wisc.edu>, jgreco@csd4.milw.wisc.edu (Joe Greco) writes:
> Definitely a logic board problem.  I would suggest that you start off
> by checking voltages.  Compare regulator and rectifier output readings
> with a functional 1541....etc....etc.

The symptom Simon Gales wrote of is exactly what happened to two of my units.
The last one just a few weeks ago, the first one several years ago.

I have several spares so I haven't gotten around to fixing the last failure.
The first was fixed with a capacitor replacement in the speed control section.
Unfortunately, I'm at work and my notes on this are at home. My recollection
was the little pup was tied to the speed control chip (a Sony tape recorder
component) as part of the closed loop feedback circuit.

This was an older ALPS unit where the speed control was on a small daughter
board. I'll look up my notes tonight but the purpose of posting such a sketchy
diagnosis was to help focus on the likely problem area and avoid being
sidetracked.

Hope this helps. I'll follow up later...