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 |   Previous Messages  |  Posted By
   flatlander on 2012-08-06 13:57:56
  |   Re: 1551 disk drive repair info
  Hans, thank you I hadn't looked too carefully at that part, cleaned it up & fixed a dodgy joint, the drive works perfectly now    Cheers
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Posted By
   Hans on 2012-08-06 02:47:06
  |   Re: 1551 disk drive repair info
  Could be a faulty "paddle", i.e. the plug. This is the main source of 1551 trouble.
  You can find some details here:
  ftp://ftp.zimmers.net/pub/cbm/schematics/drives/new/1551/index.html
  Hans.
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Posted By
   flatlander on 2012-08-05 18:06:57
  |   1551 disk drive repair info
  Hi, can anyone supply technical info to help me repair a 1551 drive. When powered up the motor runs for a few seconds and then stops, the green LED lights up OK. Nothing shows on the red LED except for a flash when powering off.  The rectifiers/regulators seem ok, power is steady at 12.14V and 5.05V. The stepper motor and head resistances seem ok too. The 2 transistors on the Newtronics driver board are ok, don't know about the LAG IC or the main board ICs. Are there any simple tests I can run to narrow down where the problem is eg voltages at certain points? I don't have a working one to compare with.
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