Neckboard RGB transistor testing?

midcoastsurf

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I am working on a Pentranics model 1132 monitor. The monitor was missing "green". I pulled the chassis and neck board for closer inspection. Two of the three transistors on the neckboard that control the three colors were a little loose. I could wiggle the transistor and noticed on the solder side that the legs were connected to the traces, but the traces had lifted off the board a little. I re-soldered all three transistors along with the header pins for the RGB input connector. Now I have lost "red" and the monitor only displays blue. Maybe I heated up the red transistor too much while re-soldering it? Is there a way to "ground" a transistor and have the color appear on the screen or another test I could do?

Thanks
 
meter

Get a meter and put it on diode check and see if all the drive transistors check the same if they do then you have other problems.
Since you lost a color after you did something retrace your work. check to see if you bent a pin on the tube putting the neck board back on. Then do a continuity check with your meter checking traces on the neck board around the drive transistors.
Check and see if you have a crack solder joint on the video plug on board.
 
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