No external leak or bulge and positive leg cut as in the first pictures.
electrocuted
Member
Last Activity: 03-05-2025, 02:53 PM
Joined: 08-23-2023
Location: tepeleni
-
+1 you guys are time and effort savers! Replaced cm867 with a 120μF/200V which was available and works fine. No external leak or bulge and positive leg cut as in the first pictures.
-
Sorry, what do you mean by 4 tensions? My english is worse than the tv condition......Leave a comment:
-
I guess not, but it may be a voltage converter problem on the tcon. I repaired some tvs in the meantime and it's the only one left in the corner...
Leave a comment:
-
Still no sign of life, plugged it cold and nothing on screen. You are right about the consumption of tcon, when disconnected and reconnected to main board the power supply drops for an instance (fan slows down and backlight turns off) then comes back on. The tcon chips remain cold during operation!Leave a comment:
-
Thanks, I'll give it a try and see what happensLeave a comment:
-
No one is familiar with this type of fault, showing this image on screen?
Leave a comment:
-
After many tests the tv won't work! The only one time the screen showed something and the led stopped blinking was this. What should I make of it?...
Leave a comment:
-
I hear you, next time I will surely know where to start from...Leave a comment:
-
Thank you too, I just could not believe that it was something simple as that!
Leave a comment:
-
Leave a comment:
-
Well, congratulations to both of you, it was a cold soldering on the negative pin of CM851. I guess this was "informing" power supply that the led inverter was operational and it would not turn on. Thanks again for the help!
Leave a comment:
-
ok thanks, I'll look into thatLeave a comment:
-
Good news!!! the tv works with shorted DS on mosfet. I guess the noise is not harmful...
what happens if I make the short permanent?
Leave a comment:
-
Done, the backlight comes on with the cable to the main board disconnected! If it is connected nothing happens. A strange high pitch noise is heard from power supply...Leave a comment:
-
I'll try that tonight because I have removed the power board from tv. If the led array is defective will it affect the inverter circuit?Leave a comment:
-
[B][URL="https://datasheetspdf.com/pdf/767766/Alpha&OmegaSemiconductors/AOD4186/1"]N-Channel MOSFET - AOD4186[/URL][/B]
[B][URL="https://datasheetspdf.com/pdf/767766/Alpha&OmegaSemiconductors/AOD4186/1"]N-Channel MOSFET - AOD4186[/URL][/B]
Leave a comment:
-
I tried with ps_on to ground with same result. Seems it has no effect on the operation of the power supply, only a load on A5V "can" switch it on. I will recheck nearby items around QM853. ps_on unconnected measures 3.3V.Leave a comment:
-
Sure, that's correct but how did the ps turn on without using the ps_on line?Leave a comment:
-
Tried it and voltage stays solid 5.2V. The strange thing is when I put the load, the voltages B5V and B12V are there on the connector! (ps_on unconnected) In fact the more amperage on the A5V line, the more voltage on B12V.
A5V B12V
0.5A 7V
>1A 13V...Leave a comment:
-
It's difficult without diagram but I see two power mosfets (D4186) to switch on B5V and B13V. The B13V output is used to turn on B5V but both fets gates are 0 Volts! Inputs on these read 5.2V and 24V(!). When I connect a 24V led bulb the voltage drops to 15.5 and the bulb lights pretty low. Then when grounding ps_on it goes even more dim! I will continue tracking......
Leave a comment:
No activity results to display
Leave a comment: