MAG LT716s front
MAG LT716s back
Closeup of fried FET
The capacitors in the first picture are failing as can be seen by their bulging. They are supposed to hold the electric charge for the inverter circuit using the 4511GM FET ICs shown above. Once the capacitor cannot hold its designed charge, the BIT3193 PWM controller in the middle of the bottom picture tells the FETs to try harder to maintain the output voltage on the capacitors. Apparently the controller had no protection for this type of scenario and drove the blown FET to the point that it melted the solder it was connected to the board with and damaged the top of the PCB. Credit: http://reboots.g-cipher.net/
3 comments
David Butler says:
November 26, 2009 at 11:38 am (UTC -5 )
I had this exact same thing happen to mine, to the same chip. It is weird seeing your picture because it looks almost exactly like mine. With my board the monitor works for about 20 min, and then the back light goes out, then if your turn it off and then back on it works for another minute or so. Were you able to find a replacement power supply? or were you able to find a hack or way around the problem?
admin says:
November 27, 2009 at 7:51 pm (UTC -5 )
Picture submitter said that after replacing FETs and the capacitors that the monitor worked fine.
reboots says:
November 28, 2009 at 8:01 pm (UTC -5 )
A quick note: I was unable to source the original 4511GM FETs. I used the Fairchild FDS8960C available at Mouser or Digi-Key as a compatible replacement. To replace the FETs in your monitor you will need to confirm the part number and type (N-channel, P-channel, dual, etc) and either find a source or a suitable replacement that matches the original package and specifications.