Osborne OCC1 problem
javickers at solutionengineers.com
Thu May 15 13:38:40 CDT 2008
OK, stranger & stranger.
The power supply has 3 identical "plugs" (for want of a better word) coming
off the board, each with 4 pins. The voltage on each corresponding pin of
each plug is identical; so I'm assuming they're there to power other
optional (and presumably never built) kit. Anyhoo...
Without my voltmeter, I've done my best to calibrate the 'scope (which I've
never used in anger before) to a sensible scale. From this scale I have
concluded that, with respect to GND:
Pin 1 has approx -13.5v - but is not connected to anything
Pin 2 has approx +12.0v
Pin 3 has approx - 0.1v (and is a bit rough, but only on the millivolt
Pin 4 has approx + 4.5v (higher, actually, somewhere between 4.5v and 5.0v
All three signals are pretty smooth, I can't see any rectification noise on
them until I get into the millivolt scales - even as far down as I can
adjust the 'scope.
The crystal is working properly :)
I've not checked the voltages going into the monitor yet - I need to do some
additional dissasembly so I can get the probe in, and it's knocking off
However, the PSU looks good, I'd say.
The display is still fritzed :(
No virus found in this outgoing message.
Checked by AVG.
Version: 7.5.524 / Virus Database: 269.23.16/1433 - Release Date: 14/05/2008
More information about the cctech