EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: nonkapo on November 03, 2019, 05:30:57 pm
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Good evening everyone.
I'm struggling with this machine some time and cant figure out where's the culprit.
The TV went dead after sudden blackout in my apartment(due to improperly designed installations and overload). After discovering the fuse is gone, replacing it and powering through serial bulb all seems fine and i assemble it. I use the TV as a monitor through HDMI port(if that does matter)and it stays non stop on. Two days later it went dead again. Figuring out there is short somewhere i change the two 68uf capacitors, the 0.12 resistors(latest have a sign of burning) and the MOSFEt(mine is a single mosfet version with 13NM60N). I have PWM HS01C but do not manage to find it during the repair and decide to skip replacing it. After the serial bulb test i switch the TV on and in 6 seconds it blow the fuse again. What do i miss(accept for the PWM)? The bridge test fine. no external signs of damage on the rest of the components?!?1? On top i cant find the schematics either(should be in the downloads section but under different name. Please advise.
Thanks
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Check the electrolytic capacitors in the power supply, particularly the bulk filter and any others on the primary side. It's common for problems to be noticed after a power failure when the capacitors are marginal, the ESR rises as they cool off.
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Thanks, the bulky one are the one already replaced. Will check the others too.But can i exclude the PWM from the suspects than?
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Well, all capacitors look ok as per the ESR, so proceeding to replacing PWM chip. Will update you on the results. Any other advices?
Thanks.
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Check PFC circuit, he's can guilty in death capacitors 68uf