21 May
2012
21 May
'12
3:06 p.m.
On May 21, 2012, at 5:20 PM, Jim McCusker wrote:
I have a working Pet 2001-8 that has one annoying issue. When I power up the unit I
typically don't see any characters displayed unless I apply a slight amount of
pressure on the back of the brightness control in the back of the monitor. I suspected
bad solder joints but couldn't see anything wrong. Turning the control brightens the
screen but somehow this control is causing the character display to turn on/off. Any
ideas what might be going on here?
Could easily be dirty contacts on the wipe for the pot. Try isopropyl
alcohol, or any number of commercially-available contact cleaners for
stereos, etc.
Or, given your description, the slight flex you're applying might be
wiggling other bad solder joints elsewhere on the board to the point
where they connect. I've had that happen (it was a nasty bugger to
find, too).
- Dave