Monitor compeltely dead. F100 & F101 blown. Lots of ugly repair work all over the deflection board. Burned traces repaired with component legs. Replaced F100/F101 and got neck glow. Spotkiller off, but no deflection or HV. Shotgunned caps & chassis transistors, reflowed all connectors. Fixed several broken wires and cold solder joints on the chassis transistor mounts. No change.
Grabbed a spare HV cage & neck board to narrow the problem to HV or deflection. Noticed that the gray ground wire on the neck PCB was nearly broken off at the solder joint. Removed, stripped, and re-soldered. No change. Checked +25v from power supply, tested good.
Disconnected everything except the coil and P100, double-checking that Q102/Q103 weren't shorted. Measured voltages at P101. Got very low, unstable voltages, pointing to LV issues.
Tested Q100/Q101 in circuit with a DMM, both looked shorted. Removed and retested; Q100 tested bad. Replaced both components. Tested R100/R101, D100/D101/D102/D103, all good.
Powered up and tested J101 again - stable ±27v.
Plugged everything in. Have HV & deflection chatter. Picture seems to be missing blue, consists mostly of dots. Turned brightness up & adjusted blue controls - monitor is working.
Interestingly, when I was diagnosing the board, I noticed that the +25VAC on pins 13/15 of P100 were swapped. According to the schematic, pin 13 goes to F100 and 15 to F101, but on the board it's the other way around. I checked two deflection boards, and they are both wired this way. It makes no difference since both pins supply +25VAC, but I thought it was interesting that they were swapped.
This was my first WG6100 repair, and while it was (from what I understand) a very common problem, I thought I would post it anyway. I really enjoy reading repair logs, and maybe this will help someone else attempting their first repair.
Grabbed a spare HV cage & neck board to narrow the problem to HV or deflection. Noticed that the gray ground wire on the neck PCB was nearly broken off at the solder joint. Removed, stripped, and re-soldered. No change. Checked +25v from power supply, tested good.
Disconnected everything except the coil and P100, double-checking that Q102/Q103 weren't shorted. Measured voltages at P101. Got very low, unstable voltages, pointing to LV issues.
Tested Q100/Q101 in circuit with a DMM, both looked shorted. Removed and retested; Q100 tested bad. Replaced both components. Tested R100/R101, D100/D101/D102/D103, all good.
Powered up and tested J101 again - stable ±27v.
Plugged everything in. Have HV & deflection chatter. Picture seems to be missing blue, consists mostly of dots. Turned brightness up & adjusted blue controls - monitor is working.
Interestingly, when I was diagnosing the board, I noticed that the +25VAC on pins 13/15 of P100 were swapped. According to the schematic, pin 13 goes to F100 and 15 to F101, but on the board it's the other way around. I checked two deflection boards, and they are both wired this way. It makes no difference since both pins supply +25VAC, but I thought it was interesting that they were swapped.
This was my first WG6100 repair, and while it was (from what I understand) a very common problem, I thought I would post it anyway. I really enjoy reading repair logs, and maybe this will help someone else attempting their first repair.
