ceronix 1793 guru needed to pick your brain

[Nepa Coin Op]

anyone here real fluent with these mons, please chime in I have one real close to up and running but cant put my finger on it, chassis was fully capped and wont start up, this is how I got it, this is where I got to it, and what I found, when probing the pins on the C5184, when I touch pin 2 with my dvom the mon will start just from the slight resistance put on that pin through my dvom and it will fire up...i dug into this pretty deep and couldnt find anything out of spec...cpr501 was also removed and all circuits on it check ok, any input is greatly appreciated


Thanks

[Trisail]

I will assume the monitor is dark, no picture. So pin 2 is the inverting input to the Error Amp, on the PWM IC. Touching it with the dvom probe will probably add or subtract some capacitance/resistance. It's close to pin 3 the COMP pin too. If all the caps that were installed are good - and no 'mistakes' were made - I would just start replacing the major components in this order if you want to know what the culprit is. If not, just replace what you can and see if you can fix it. You said it had a recap? All of them? even the big ones? The ones you usually don't have to do...  PS - Could be a solder blob/solder jumper, bad solder joint on a cap, lifted/bad trace from the cap job, some trace not entirely connected where it should be....

PWM XRC5184 - VERT DEF LA7830 - (CRT DSDC  LA7851 I haven't fixed any 1492's with this one yet)

Could be a resistor or dipped cap, most likely not, but.
Tony

[Nepa Coin Op]

I will assume the monitor is dark, no picture. So pin 2 is the inverting input to the Error Amp, on the PWM IC. Touching it with the dvom probe will probably add or subtract some capacitance/resistance. It's close to pin 3 the COMP pin too. If all the caps that were installed are good - and no 'mistakes' were made - I would just start replacing the major components in this order if you want to know what the culprit is. If not, just replace what you can and see if you can fix it. You said it had a recap? All of them? even the big ones? The ones you usually don't have to do...  PS - Could be a solder blob/solder jumper, bad solder joint on a cap, lifted/bad trace from the cap job, some trace not entirely connected where it should be....

PWM XRC5184 - VERT DEF LA7830 - (CRT DSDC  LA7851 I haven't fixed any 1492's with this one yet)

Could be a resistor or dipped cap, most likely not, but.
Tony

ill go over these areas and report back, yes full cap except large filters were done, I agree traces on this chassis are horrible and easily lifted i had repaired a few already, 5184 was swapped I will try the rest and see where I end up


Thank You