Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mailrus!csd4.milw.wisc.edu!jgreco
From: jgreco@csd4.milw.wisc.edu (Joe Greco)
Newsgroups: comp.sys.cbm
Subject: Re: 1541 problem
Message-ID: <2700@csd4.milw.wisc.edu>
Date: 31 May 89 04:48:53 GMT
References: <11793@s.ms.uky.edu>
Sender: news@csd4.milw.wisc.edu
Reply-To: jgreco@csd4.milw.wisc.edu (Joe Greco)
Organization: UW-Milwaukee Home for Out-of-date 8 bit Hackers
Lines: 41

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.
]
]I have isolated the problem to be on the main logic board; the 6502 and
]the two 6522's are working ok.  I swapped things around with a working 
]1541 to figure this out.
]
]The logic board says:
]	PCB NO 1540050   COPYRIGHT 1982
]	REV C  W-1894MB  MADE IN JAPAN									404E
]

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.

MY next step, failing that, would be to check the ROM's.  Commodore in
their infinite wisdom placed one of the ROM's right next to the heat
sink of one of the regulators (that may have changed in later
revisions, I HOPE!) and several of my ROM's have literally fried to
death.  If this is the case, burn an EPROM and pop a fan on the darn
drive, as it will more than likely happen again.

CPU works?  PIA's work?  Start checking the other logic.  Swap other
chips.  Static RAM and all.  If all of those check out, you are in
serious trouble.  Unless you are seriously into electronics, I suggest
taking it to the shop.  (if you ARE into electronics, start checking
to see what happens on the various busses and control signals, since
the symptoms indicate that the CPU isn't getting very far into the
reset routine).

Frustrated?  Try a sledge hammer.  It's been known to work.  ;-)

And remember, anything you do is at your own risk....
--
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