Good day folks. Typical Vestel power supply problem here: someone left their TV plugged in during a power outage and when it came back it fried the power supply of this TV. The board is a 17IPS61-3. The primary was completely destroyed: there were many many blown things on it and I changed what I believe to be everything (thermistor, MOSFET IC, bridge rectifier, couple of SMD resistors, fuse (duuh)) but it still has no output AT ALL. It doesn't blow anything, but it just sits there doing nothing.
I even found the schematic, which was VERY handy, but the secondary side is not exactly the same thing - I found some things which vary between my board and the circuit in the schematic. The weirdest part is the STBY pin (pin9 in the schematic): mine doesn't appear to be connected to anything ! It's connected to a trace which has solder pads on it, but no other components, so WTH ? How does this thing work ? Does it run straight off the 12v rail which is always on ? It could be a different revision or model number. The main board is a 17MB82-2 if it matters. The diodes in the secondary are notorious for going bad, but these ones seem OK. I definitely think I'm not getting any drive from the primary.
Another thing I've noticed: I'm getting 325V on the main capacitor, but the VCC pin of the MOSFET IC seems very unstable: it jumps around 10,15,22V, etc and never seems to stabilize.... I attached the schematic to make it easier for you guys to suggest what to check. Could it be a bad optocoupler ? The diode and resistor that are connected to it were destroyed, so maybe they took out the opto with them ? :| ReeceyBurger123 made a video once which shows how a bad optocoupler shuts down the whole board and the TV has no standby - haven't tried freezing mine yet though. Cheers.
I even found the schematic, which was VERY handy, but the secondary side is not exactly the same thing - I found some things which vary between my board and the circuit in the schematic. The weirdest part is the STBY pin (pin9 in the schematic): mine doesn't appear to be connected to anything ! It's connected to a trace which has solder pads on it, but no other components, so WTH ? How does this thing work ? Does it run straight off the 12v rail which is always on ? It could be a different revision or model number. The main board is a 17MB82-2 if it matters. The diodes in the secondary are notorious for going bad, but these ones seem OK. I definitely think I'm not getting any drive from the primary.
Another thing I've noticed: I'm getting 325V on the main capacitor, but the VCC pin of the MOSFET IC seems very unstable: it jumps around 10,15,22V, etc and never seems to stabilize.... I attached the schematic to make it easier for you guys to suggest what to check. Could it be a bad optocoupler ? The diode and resistor that are connected to it were destroyed, so maybe they took out the opto with them ? :| ReeceyBurger123 made a video once which shows how a bad optocoupler shuts down the whole board and the TV has no standby - haven't tried freezing mine yet though. Cheers.
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