Ahhhh! Help! Got a philips 2b TV set (actually a Pioneer sv-2103). Arrived with shorted HOT and a couple of (safe) resistors burned out. Replaced all of them and turned on the set through a "bulb limiter". SMPS seems working: 140V, +20 and-20 and +13V lines were all low (because of the bulb) but present and reasonable. Scoping primary and secondary sides of the SMPS gave me signals in good shape.... But: no HT, no standby 5V. Signals in horizontal path were ugly. Replaced the LOPT. Now I have good shaped signals in the horizontal path, good signal @ HOT's collector, some HT, some filament current, some standby 5V. So I decided to go without series bulb. ... opss! Something is now tripping down the SMPS after few milliseconds. To better trace the problem I connected a bulb in place of the HOT:
140V in perfect as they are +20 and -20 and 13V ... confirming the SMPS is properly working. Turning the 140V trimmer effectively regulates B+ as expected, letting me argue that the SMPS' regulator is also working properly . Suspecting something in the HOT circuit I replaced the two (damper?) diodes, the resonating cap, checked resistors .... without any result. Turning back to the series bulb arrangement, the circuit doesn't trip working as described before... but with further testing I noted that sometime the signal @ the HOT's collector is somehow irregular. Sometime it shows a third irregular swing in the middle of the main two.. -> checked EAST-WEST correction circuitry... it seems ok.....Ahhhh! HELP!!
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