$70.00 lesson learn after buying a power supply
For the last week I have been working on a 50” Panasonic Plasma TV, model TH-50PX80U.
The problem was when you press the power button, the TV will turn on and you can hear clicking noises coming from the power supply. Then the screen lights up for about 3 to 5 seconds and then the power turn off. No picture was display in the 3 to 5 seconds. I have checked all voltages according to the service manual and which all was good. I also disconnected SS board and SU board to see what effect it will have on the power supply and still no change.
Next I started to check the caps and checking for shorts on the power supply and all check well. Then I started checking caps and checking for shorts on the SS board and SU board I found none. So I assumed the power was bad.
I did a visual inspection of the three data drive board C1, C2 and C3. Then I check the 5 volt supply pin of C3 board for a short and found nothing. I never unplug the power connector for the C3 board and didn’t attempt to power up the TV with no power to the C3 board. This is when I learn my $70.00 lesson
I order another power supply from eBay and once it arrived I install it and guess what? I was still having the same problem. So now I finally decided to unplug the power cable coming from SS board to the C3 board and then the TV stay power on to my surprise! After that I started to focus on the C3 board. The C3 board has three ribbons connector to drive sections of the screen. Removing the C3 board and getting a closer look under a magnifier glass I notice 2 surface mount 6.8 ohm resistor dark in color near first ribbon of the plasma screen. I replace the two resistor and they burn out again upon retesting. So checking the schematic of the C3 board to see what these two 6.8 ohm resistor was doing. After checking the schematic I decided to leave off the two 6.8 ohm resistor and unplug that ribbon for that section of the screen. Again I was surprise the TV power up and I got a picture!
This prompted me to look at the C3 board more closely especially the pin out of the ribbon connector that drives that section of the screen. So I check the ribbon pin label VDD and GND and found they were shorted. WOW!
Now my question is(but I think I already know the answer) can this be repair?
What should I do with a 50” plasma TV that only display about 90% of a picture?
Scrap it? Sell it? Use as is?
For the last week I have been working on a 50” Panasonic Plasma TV, model TH-50PX80U.
The problem was when you press the power button, the TV will turn on and you can hear clicking noises coming from the power supply. Then the screen lights up for about 3 to 5 seconds and then the power turn off. No picture was display in the 3 to 5 seconds. I have checked all voltages according to the service manual and which all was good. I also disconnected SS board and SU board to see what effect it will have on the power supply and still no change.
Next I started to check the caps and checking for shorts on the power supply and all check well. Then I started checking caps and checking for shorts on the SS board and SU board I found none. So I assumed the power was bad.
I did a visual inspection of the three data drive board C1, C2 and C3. Then I check the 5 volt supply pin of C3 board for a short and found nothing. I never unplug the power connector for the C3 board and didn’t attempt to power up the TV with no power to the C3 board. This is when I learn my $70.00 lesson
I order another power supply from eBay and once it arrived I install it and guess what? I was still having the same problem. So now I finally decided to unplug the power cable coming from SS board to the C3 board and then the TV stay power on to my surprise! After that I started to focus on the C3 board. The C3 board has three ribbons connector to drive sections of the screen. Removing the C3 board and getting a closer look under a magnifier glass I notice 2 surface mount 6.8 ohm resistor dark in color near first ribbon of the plasma screen. I replace the two resistor and they burn out again upon retesting. So checking the schematic of the C3 board to see what these two 6.8 ohm resistor was doing. After checking the schematic I decided to leave off the two 6.8 ohm resistor and unplug that ribbon for that section of the screen. Again I was surprise the TV power up and I got a picture!
This prompted me to look at the C3 board more closely especially the pin out of the ribbon connector that drives that section of the screen. So I check the ribbon pin label VDD and GND and found they were shorted. WOW!
Now my question is(but I think I already know the answer) can this be repair?
What should I do with a 50” plasma TV that only display about 90% of a picture?
Scrap it? Sell it? Use as is?
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