Hey guys, I've done a cap kit on the monitor Chassis and neck board now. I even replaced a few of the electrolytic caps that are not listed in the cap kit (all the ones pertaining to the hsize pot/opamp). I still cannot adjust the horizontal size though replacing the caps did tighten the image enough for it to not cut off much. Do either of you know the expected voltage of VR2 or the voltage levels for U1? I measured 19V going to VR2 and adjusting the pot I does change the level on the op amp side. The pot ohms out to the full 50k range so the pot is good. Would I maybe need to adjust VR3?
Any idea where to go with this? I'm not very familiar with these CRT boards. I'd imagine that if the Op Amp is bad I would have a messed up display. I haven't pulled the resistors to see if they are good (can't ohm them out in circuit with all the components in parallel). That seems a bit far fetched though because none of them look damaged or burnt.
I just noticed this referencing the schematic, I should have 20-27V on the pot. Seeing as how I only measure 19 could that be a problem?
I'm working on a Tatung Type 38 Monitor in a Megatouch Diamond
According to Merit it uses the same chassis/neck board as the Type 66 so I'm using this schematic:
http://www.meritind.com/Service%20Center/Type%2066.jpgI ohmed out the ground pin on the plug to the chassis and made sure that all the boards are tied to chassis ground (mostly in troubleshooting the touch screen which still isn't working right).
I see no leaking cap, no burnt components, no damage on the board. I work on circuit boards for a living so I am good with rework, just out of practice in troubleshooting and kinda of scared to probe around a 120V PCB.
Not sure what other info that would be helpful to you.