Hi Guys,
This television came in without a picture two weeks back. It was switching on with the led going from red to blue.
The 24v & Blon were present, so I took the inverter pcb out to check for shorts.
The invertor pcb divides the 24v to two banks of cemfets. One of the 7amp fuse's suppling one of the banks was open, with a dead short on that particular bank of cemfets. (AO4614B)
I replaced Q321 AO4614B with an AO4614. (no B)
The specs' show the AO4614B capable of handling 30amps pulsed drain current, the AO4614 20amps pulsed drain current.
The set has come back with Q321 short & fuse blown again. (obviously weaker)
I've replaced with the same AO4614. (No AO4614B on hand & cust eager)
Why after running awhile do all the cemfets get very hot?
(can't believe some thing so small can endure this heat) see photo
Busy trying to source the AO4614B.
It is an old Lcd, and I'm sure the panel has seen many hours.
Should I replace all of them in one go, or one at a time as they fail??
Seems like a silly question, I just need some input please.
This television came in without a picture two weeks back. It was switching on with the led going from red to blue.
The 24v & Blon were present, so I took the inverter pcb out to check for shorts.
The invertor pcb divides the 24v to two banks of cemfets. One of the 7amp fuse's suppling one of the banks was open, with a dead short on that particular bank of cemfets. (AO4614B)
I replaced Q321 AO4614B with an AO4614. (no B)
The specs' show the AO4614B capable of handling 30amps pulsed drain current, the AO4614 20amps pulsed drain current.
The set has come back with Q321 short & fuse blown again. (obviously weaker)
I've replaced with the same AO4614. (No AO4614B on hand & cust eager)
Why after running awhile do all the cemfets get very hot?
(can't believe some thing so small can endure this heat) see photo
Busy trying to source the AO4614B.
It is an old Lcd, and I'm sure the panel has seen many hours.
Should I replace all of them in one go, or one at a time as they fail??
Seems like a silly question, I just need some input please.
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