Guys, I need your advise to troubleshoot the Ysus board on Samsung PN64F8500. The symptoms are as follows:
When switching the TV on via remote, no video, blinking LED for about 1 min. Then sound is on, all remote controls are fully functional, but still no video. If I am lucky, it works from the 2nd switch on depending on the room temperature.
First, I was thinking that it was the power board, bad capacitors. I have checked all electrolytic capacitors, measured ESR (I use Atlas ESR70), but could not find any faulty ones.
One more thing. It looks as the ambient temperature affects it a lot. It works perfectly fine when it is below 22 °C, switches on from the 2nd try under 22 °C – 24 °C, and almost impossible to switch over 25 °C.
According to many threads, having sound and no video means problems with the Ysus board. So, I have checked all electrolytic capacitors on the Ysus board and again could not find any bad ones. Still I replaced most of electrolytic caps, but it didn't help. Then I found this thread on avsforum - people had a very similar problem with the PN64F8500, which was fixed by replacing 106 MLCC caps on the Ysus board. I removed the suspected 106 caps, a few of them measure only 8uf, which is just below the tolerance level.
I can only measure capacitance over 1uf with the Atlas and am not sure if I want to buy a decent LCR meter to measure all MLCC.
What shall I do next? I am thinking to replace all 106 caps, but maybe it makes sense to replace all ceramic caps on the Ysus board because the TV is 6 years old?
Since the TV is very sensitive to the ambient temperature and can be switched on only below 22 °C, should it be only because of a faulty ceramic cap?
Any suggestions? Just replace all caps blindly or narrow bad ceramic caps down somehow without LCR?
Thanks!
When switching the TV on via remote, no video, blinking LED for about 1 min. Then sound is on, all remote controls are fully functional, but still no video. If I am lucky, it works from the 2nd switch on depending on the room temperature.
First, I was thinking that it was the power board, bad capacitors. I have checked all electrolytic capacitors, measured ESR (I use Atlas ESR70), but could not find any faulty ones.
One more thing. It looks as the ambient temperature affects it a lot. It works perfectly fine when it is below 22 °C, switches on from the 2nd try under 22 °C – 24 °C, and almost impossible to switch over 25 °C.
According to many threads, having sound and no video means problems with the Ysus board. So, I have checked all electrolytic capacitors on the Ysus board and again could not find any bad ones. Still I replaced most of electrolytic caps, but it didn't help. Then I found this thread on avsforum - people had a very similar problem with the PN64F8500, which was fixed by replacing 106 MLCC caps on the Ysus board. I removed the suspected 106 caps, a few of them measure only 8uf, which is just below the tolerance level.
I can only measure capacitance over 1uf with the Atlas and am not sure if I want to buy a decent LCR meter to measure all MLCC.
What shall I do next? I am thinking to replace all 106 caps, but maybe it makes sense to replace all ceramic caps on the Ysus board because the TV is 6 years old?
Since the TV is very sensitive to the ambient temperature and can be switched on only below 22 °C, should it be only because of a faulty ceramic cap?
Any suggestions? Just replace all caps blindly or narrow bad ceramic caps down somehow without LCR?
Thanks!
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