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- Path: spacenns.space.honeywell.com!usenet
- From: bjheyboer@space.honeywell.com (Brian Heyboer)
- Newsgroups: comp.sys.cbm
- Subject: Re: ILL 1541 :-(
- Date: 9 Mar 1996 20:54:08 GMT
- Organization: Honeywell Space Systems
- Distribution: world
- Message-ID: <4hsr5g$2i1@spacenns.space.honeywell.com>
- References: <4hpksd$kjj@nic.ftns.no>
- NNTP-Posting-Host: bjheyboer.space.honeywell.com
-
- In article <4hpksd$kjj@nic.ftns.no> Parminder Singh <singh@deko.no> writes:
- >Does anyone have a textfile containing tips on servicing
- >a 1541 (the old one, with the long circuit board).
- >
- >When i turn the drive on, the RED LED (motor on?), goes on,
- >but the motor does not spin. This is all that happens.
- >
- >Both +5v and +12v is ok. When i hook it up to PC64 (emulator)
- >it recognizes the drive ok.
- >
- >Does anyone have a clue to what is wrong????
-
- This is an indication that the drive is not completing its power-up sequence --
- the last thing it does is stop the drive spin. Several things can cause that,
- but the usual one is a bad 901229-05 ROM. Other chips that can cause this
- symptom (in order of likelyhood, at least to my experience) are a bad 6502,
- 6522, RAM, or one of several TTL "glue" chips in the reset circuit.
-
- If it is the ROM and you replace it with an EPROM, you'll never have the
- trouble again (the ceramic-packaged EPROM has better thermal characteristics
- than the plastic-packaged ROM).
-