Hello everyone!
This 7" TV was operated as a secuirity monitor for many years and was dead. No led no reaction.
The main problem was with Q7 a SOT-23 AO3400 mosfet which was shorted.
I replaced that part with IRLML6244TRPBF.
Some capacitors had high ESR so i replaced about 4-5 with such a problem.
Upon putting everything back together the image ofo LCD has "lines" and seems to be missing a colour or something. (Check images). If i applied less pressure or "twist" the case it did disappear for some time. I thought it could be the LCD's flex but moving it around doesn't seem to cure the problem. Now the problem is always there.
I ended up replacing almost all electrolytic capacitors (30+) but problem still there. Do you think it is a problem of the LCD panel?
Voltages are:
+33V = 32.5V
+15V = 15V
+8V = 8.1V
-15V = -16.1V (A bit off)
IC5 operates quite hot at around 70 celcius.
P.S. Sorry i could not find a photo of the bottom of the PCB. If it is needed i will dissasemble the TV to get some more pics.
Thanks for any input!
This 7" TV was operated as a secuirity monitor for many years and was dead. No led no reaction.
The main problem was with Q7 a SOT-23 AO3400 mosfet which was shorted.
I replaced that part with IRLML6244TRPBF.
Some capacitors had high ESR so i replaced about 4-5 with such a problem.
Upon putting everything back together the image ofo LCD has "lines" and seems to be missing a colour or something. (Check images). If i applied less pressure or "twist" the case it did disappear for some time. I thought it could be the LCD's flex but moving it around doesn't seem to cure the problem. Now the problem is always there.
I ended up replacing almost all electrolytic capacitors (30+) but problem still there. Do you think it is a problem of the LCD panel?
Voltages are:
+33V = 32.5V
+15V = 15V
+8V = 8.1V
-15V = -16.1V (A bit off)
IC5 operates quite hot at around 70 celcius.
P.S. Sorry i could not find a photo of the bottom of the PCB. If it is needed i will dissasemble the TV to get some more pics.
Thanks for any input!
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