68kMLA Classic Interface

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Plus CRT?
Posted by: Fred1212 on 2024-09-25 21:51:49
Have a 512k/plus AB. It's been recapped and cr20 replaced and no longer fup fup fup. Plus DB chimes but screen is dead. Screen does work on another supply and the HT is alive (spark test). I've reflowed the connectors and have tested 11.5v on the CRT electron gun but it does not show any indication of heating. Seems odd that the volts are there but no heating?
Any thoughts
Posted by: dv- on 2024-09-26 12:15:44
Did you check for shorts in the DB/AB connectors? When I recapped one of mine recently I reflowed the connections, as one does. But my soldering-noob-self accidentally made bridged composite video signal to ground. Careless. But it gave me a black screen and other symptoms were very similar to what you describe.
Posted by: Fred1212 on 2024-09-27 17:19:17
Yes checked all soldering. Have moved on a bit I cleaned all the CRT contacts and have managed to get a single bright horizontal line now. Yoke connector is OK looking at the Q2 Q4 and Q5 area.
Posted by: Fred1212 on 2024-09-28 01:34:24
Upadte - working. Faulty components Q1,Q2 & Q4.
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