Engel Led tv problem

[Lavek666]

Started few mounts ago with winter TV not turnig on until i heated it up with my halogen heater, but worked normaly after cold start turn of and on without problem, and now when winter is over it was starting sometimes even without heating till today no start.
Opened it blown fuse and some black burning around this transistor https://ibb.co/cTMkdc https://ibb.co/eokYWx.
Replaced fuse and as soon as i conected power boom fuse gone and crack from transistor like capacitor discharged on him, i desoldered it and check it with multimeter and he is working fine, check all diodes and some other components evrything seems ok but obviusly i am missing something, i soldered other fuse and try to power on without transistor soldered and i get 5v on standby but no light on and i have power normaly until that transistor and transformator. what could it be that is discarging capacitor trew transistor or is it discharging because fuse is blown?
https://ibb.co/k0ATyc
https://ibb.co/k1xmjH

[budm]

Re: Engel Led tv problem

We need good clear straight shot pictures of the whole top side and the bottom side of the board so we trace out the circuit and able to read printed texts on the board. Please upload the pictures here at B.C.
We do not have the board in front of us to look at so the better the pictures are the better help you will get.
BTW, what is the history of this TV? Any one else worked on it before you?

[Lavek666]

Re: Engel Led tv problem

We need good clear straight shot pictures of the whole top side and the bottom side of the board so we trace out the circuit and able to read printed texts on the board. Please upload the pictures here at B.C.
We do not have the board in front of us to look at so the better the pictures are the better help you will get.
BTW, what is the history of this TV? Any one else worked on it before you?

No work on TV , bough it a few years ago i don't even remember how long exactly but around 5years and was working perfectly till now.
I soldered glass fuse same spec as the one before but it is difrent IT WAS SR-5-3.15A-AP and on heatsink transistor is middin because it is desoldered curently ot is SW10N65 transistor.

[dick_barton]

Re: Engel Led tv problem

Is this your power supply?
https://www.electronica-pt.com/esque...le32d99-30367/

[petehall347]

Re: Engel Led tv problem

heat making things work is mostly bad capacitors or bad solder joints .. sometimes it can also be a transistor . heat makes better connections sometimes.

[Lavek666]

Re: Engel Led tv problem

Is this your power supply?
https://www.electronica-pt.com/esque...le32d99-30367/

Didn`t have time to check evrything because i have to go to work, but it seams that it is that board

[Lavek666]

Re: Engel Led tv problem

Didn`t have time to check evrything because i have to go to work, but it seams that it is that board

What should i look for that is discarging those 2 big capacitor on Q4 and blowing fuse . all diodes and transistors are good other components not sure how much should it be on some resistors that are almoust without resistance

[Lavek666]

Re: Engel Led tv problem

Well look's like i solved my problem, tested evrything good and then just decided to resolder evry component around transistor and now it is working

[ljintexas]

Re: Engel Led tv problem

Ya just gotta love lead free solder!

[Lavek666]

Re: Engel Led tv problem

Well look's like i solved my problem, tested evrything good and then just decided to resolder evry component around transistor and now it is working

Acctualy problem wasn't in bad solder, i bought thermal paste mount transisto on heatsink and boom goes again discharge on transistor, transistor is somehow shorting to ground on sink, no wisible damaged but i isolated litle screw that holds transistor , mount transistor and now it is good.
Thanks for trying to help evryone

[dick_barton]

Re: Engel Led tv problem

Did you replace the original transistor (SW10N65 which is a mosfet) with one that has a metal back on it. If you did then the metal back, which is the Drain, will short to the heatsink.

[vinceroger69]

Re: Engel Led tv problem

i would replace that mosfet with a new one as may have a hairline crack you cant see in the casing etc