This monitor was knocked over by the household kitty (another reason to have a dog). It caused the connection where the external power supply connects to be a little loose. The owner tried to fix it himself, and it worked for awhile, but eventually it must have shorted something out.
The power supply tests at 12.5v. I found bad caps at EC1 and C58, both 470uf, 16v, on the power board. I had replaced these and powered it up.
When turned on, the power board/inverter connection shows proper voltages, but the on/off wire is not on and the red power led flashes. I then found another bad cap at C5, 220uf, 25v, on the inverter.
The inverter also has a blown fuse at F1, not sure what size.
There are two 8 pin smd's on the inverter board labeled U1 and U2. When I test them with the ohm meter two legs across from each other on U1 show a closed circuit, which is different from U2. B3942, C8501, T0820 is what is printed on each of them, and appears to be a mosfet?
I am learning electronics and have only gotten to this problem a couple of times and am in over my head. Can someone help me with what steps to try next to figure out if this can be repaired within reason before trying to replace one or two parts at a time and hoping it will work? I realize something shorted to blow the fuse, but is it the mosfet, or does something else short that causes the mosfet to short also, could there be a dozen components that also got shorted?
Thanks.
The power supply tests at 12.5v. I found bad caps at EC1 and C58, both 470uf, 16v, on the power board. I had replaced these and powered it up.
When turned on, the power board/inverter connection shows proper voltages, but the on/off wire is not on and the red power led flashes. I then found another bad cap at C5, 220uf, 25v, on the inverter.
The inverter also has a blown fuse at F1, not sure what size.
There are two 8 pin smd's on the inverter board labeled U1 and U2. When I test them with the ohm meter two legs across from each other on U1 show a closed circuit, which is different from U2. B3942, C8501, T0820 is what is printed on each of them, and appears to be a mosfet?
I am learning electronics and have only gotten to this problem a couple of times and am in over my head. Can someone help me with what steps to try next to figure out if this can be repaired within reason before trying to replace one or two parts at a time and hoping it will work? I realize something shorted to blow the fuse, but is it the mosfet, or does something else short that causes the mosfet to short also, could there be a dozen components that also got shorted?
Thanks.
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