mustang6771
New member
I've been commenting on an awesome Polo post by Mecha but didn't want to hijack it any longer - I need to keep track of my progress.
I guess I'll run down everything step by step and maybe someone can help me figure out what next to try out.
Hantarex Polo 25 Monitor - Blind. I have no game to try it out with currently, just a JPAC; however, turning the brightness up does nothing.
-When first received I could hear the high voltage. Disconnected the flyback and could then hear the HOT (I believe). Monitor got all static-y.
-B+ at TP6 tested out at about 138V
-No heater glow visible.
-R35 on neck board checks out fine.
-Solders on xfmr look good, traces look good and test out for continuity, and visual inspection of transformer shows no problems.
-I notice B+ filter caps are bulged out. Replace them with new like kind (330uf 200V - I have noticed other monitors of same model with larger size caps).
-Resoldered a cement resistor nearby as pad was lifting - fixed.
-Power up monitor to test it out, now there is only the OCP ticking coming from monitor.
-B+ measures between 0-5V cycling.
-Install new HOT.
-Test D116-119, 134, 135 - none are shorted.
-Test C174, 175, 172 - C172 test out as shorted, remove it from circuit and it does not test out as shorted any longer.
-Continuity test the xfmr - 5 pins plus the ground pin are all continuous to each other and thus ground - unsure if this is normal. Remove XFMR from board and test each pin - none are now continuous. Reinstalled the xfmr.
I'm sort of at a loss as to what to try next. I don't have a ton of spare parts lying around. I have a cap kit to install but don't want to do that work until I get something on screen.
Any help is appreciated.
I guess I'll run down everything step by step and maybe someone can help me figure out what next to try out.
Hantarex Polo 25 Monitor - Blind. I have no game to try it out with currently, just a JPAC; however, turning the brightness up does nothing.
-When first received I could hear the high voltage. Disconnected the flyback and could then hear the HOT (I believe). Monitor got all static-y.
-B+ at TP6 tested out at about 138V
-No heater glow visible.
-R35 on neck board checks out fine.
-Solders on xfmr look good, traces look good and test out for continuity, and visual inspection of transformer shows no problems.
-I notice B+ filter caps are bulged out. Replace them with new like kind (330uf 200V - I have noticed other monitors of same model with larger size caps).
-Resoldered a cement resistor nearby as pad was lifting - fixed.
-Power up monitor to test it out, now there is only the OCP ticking coming from monitor.
-B+ measures between 0-5V cycling.
-Install new HOT.
-Test D116-119, 134, 135 - none are shorted.
-Test C174, 175, 172 - C172 test out as shorted, remove it from circuit and it does not test out as shorted any longer.
-Continuity test the xfmr - 5 pins plus the ground pin are all continuous to each other and thus ground - unsure if this is normal. Remove XFMR from board and test each pin - none are now continuous. Reinstalled the xfmr.
I'm sort of at a loss as to what to try next. I don't have a ton of spare parts lying around. I have a cap kit to install but don't want to do that work until I get something on screen.
Any help is appreciated.