gak662015

24

hace 5 años

Sorry for my limited information, I will try to expand the information.
I am repairing a LG OM 5541 music system from a friend who reportedly plugged in the equipment to listen to music while welding with an electric welder and shared the extension between the welder and the equipment.
In a moment the team turned off and didn't turn on anymore.
I started by checking the main board and came to the conclusion that I had to buy another one, which I did and dedicated myself to repair the source.
Following the post of I repair I came to replace almost all the tensions of that source.

gak662015

24

hace 5 años

The only voltage that I could not replace is PDVV, I started supplanting Q911 and so I was able to feed the IC911 oscillator with 18v until everything was fine, but the Mosfet Q901 was damaged, but what displaces me is that without the Mos placed and checking with the tester digital what would be Drain with Source is short and I don't know if this is normal. Before changing the Most I would like to be sure not to burn the new one.
Thank you

gak662015

24

hace 5 años

Thank you very much Jomi for the information, yesterday I was reviewing in more detail the area of the short and I could find the ZD 912 in short. Tomorrow Monday I will buy the Mosfet and the zener again.
I would like you to recommend a replacement for the Mosfet. I got an 11N80C3 and the one I get is the 20MN60, is it useful for me? Thank you

jomi

38.143

hace 5 años

You could try. The only difference is the DS voltage that in the original is 800V and the 20MN60 600V. Try to get one with 11W, 800V ,, 11A with TO220 FP gasket.
If I helped you, don't forget to rate

gak662015

24

hace 5 años

Good morning, I was able to replace the 22v zener (UZ 912 = UZ-208SB), I changed the Mosfet again for a 20N60, I have the 18V of IC911 (NCP 150) and still I can't get the PDVV voltage.

gak662015

24

hace 5 años

I could replace the ic 911 1250, now in the pin 4 of this integrated power supply against pin 1 which is gnd I have 10V instead of 18vV as I had with the one in bad condition, I would only have to change the SN 431A regulator but not I get it nowhere, I have another source from another LG that in that place has a TL431.
Is the TL431 replacement of SN 431? Thank you