Quote:
Originally Posted by old_coot88
WooHoo!  So was C28 connected to the wrong pin or somethin'? Does the contrast control now work? For the heck of it, might as well reconnect the diode and see if anything's coming through the IFs. But be sure and keep your needlenose clamped on the diode's lead as a heatsink until the joint cools. Such an ancient diode may be prone to heat damage.
oc |
I think the contrast control might be bad. When I rotate it in one direction it becomes shorted to ground. Adjusting the control does not give me similar contrast adjustment in the raster. If I adjust the control quickly the raster sort of flashes briefly and then goes back to the original level. I've previously cleaned the control with contact cleaner and the knob rotates freely. Is it possible to temporarily use a normal 1500ohm resistor in it's place for testing purposes?