OK I read the other posts and found same burned board and Q9101 shorted as budm
So I replaced the Q9101 (ordered from mouser) anyway it worked great for 3 hours and blacked out so i pulled the board and same mosfet Q9101 is shorted again.. there are 3 very brown spots on this board over the two in the middle QM801cs and qm802cs also brown at the 4 diodes at very top of cold section DM841-844 C they seem to be getting hot also... i bought 5 mosfets but don't want to waste another without trying to isolate the cause.. a long shot could be a defective new part but i doubt that seeing the heat marks...
What would cause that mosfet to fail??
After checking all the diodes and other components on the board and they seem good.. so i put another new Mosfet on it Q9101.. this time i added some of the silicone heat sink to help cool the hot devices. I haven't run the set yet, but overnight two more things occurred to me..
1. could the capacitors cause this? they seem good but i did not pull them out of circuit.
2. Could the LED backlight brightness be too high causing this?
Perhaps experience could enlighten me.... Thanks
So I replaced the Q9101 (ordered from mouser) anyway it worked great for 3 hours and blacked out so i pulled the board and same mosfet Q9101 is shorted again.. there are 3 very brown spots on this board over the two in the middle QM801cs and qm802cs also brown at the 4 diodes at very top of cold section DM841-844 C they seem to be getting hot also... i bought 5 mosfets but don't want to waste another without trying to isolate the cause.. a long shot could be a defective new part but i doubt that seeing the heat marks...
What would cause that mosfet to fail??
After checking all the diodes and other components on the board and they seem good.. so i put another new Mosfet on it Q9101.. this time i added some of the silicone heat sink to help cool the hot devices. I haven't run the set yet, but overnight two more things occurred to me..
1. could the capacitors cause this? they seem good but i did not pull them out of circuit.
2. Could the LED backlight brightness be too high causing this?
Perhaps experience could enlighten me.... Thanks
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