Two 1541-II drives with problems

From: Ville Laustela <*ville.laustela_at_gmail.com*> Date: Sat, 19 Apr 2014 15:14:23 +0300 Message-Id: <8796FB9F-6B92-4A2A-B70B-8BCD49F9711F@gmail.com> · ville.laustela_at_gmail.com

Hello!

I found out that I own two Commodore 1541-II disk drives, both in a non-working state.

Testing with a measured-good PSU, I got the following results with both drives:

- power on: normal activity (power led on, spindle runs and drive led lights for few seconds, then stop)
- connected to a C64: drive resets with the computer normally
- attempting to load halts at "SEARCHING FOR": drive spins (with leds on) but the stepper doesn't move. Only way out is to reset the computer.

By the Ray Carlsen's website (http://personalpages.tds.net/~rcarlsen/cbm/1541/1541-II/1541-II.txt) these symptoms point to either U7 logic chip (7406) or U6 VIA (6522). On one of the two drives I replaced the U7 chip but that had no effect.

Before I start a (lenghty, painful, boring...) removal of the 6522 VIA, I would like to ask here if anyone would have any other ideas?

Cheers,
Ville

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