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I have a Tovis/Happ Vision Pro model MTG-1901CN chassis.
The previous owner installed a new cap kit recently with Nichicon caps and said the monitor ran a while and just died. No blown fuse. I cannot get high voltage/raster. I have no heater voltage or glow. I DO have all 3 SMPS voltages as shown. B+ is right on the money at 122.9 volts and I also have the 12v & 24v. I lifted D361 to bypass the shutdown circuit but no change. The flyback is new from APAR. The HOT checks fine along with the 2.6W ceramic resistor. I even changed the neck board. I used Randy Fromm's flow chart and checked R562 & R401 like it said. The board used to take about 10 seconds to build up to the 123 volts B+. I changed Q801 as it looked charbroiled and checked all surrounding components. Since then, the B+ only takes a second to build up so apparently Q801 was weakened by heat. That's the only damage I could see. I checked the board for any bad connections and really didn't see anything out of the ordinary. No heater voltage either. I am assuming the heater voltage comes from the flyback. I don't mean to sound ignorant but what triggers the flyback to powering up or does it just happen on its own? Can I use my o-scope to find any clues here? I have found very little info on the monitor other than what the late and great Ken Layton and Ohmerone post
I am missing something somewhere. Anyway, any help with this would certainly be appreciated. I am stumped on this one! This model always gives me fits with repair.
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