The set got for repair in dead condition. Set has stopped working after a lightning, the party said.
Click on the pictures to Zoom In.
Click on the pictures to Zoom In.
I opened the back cover. Checked the components at the SMPS [power supply regulator] board, as it might be most hit by lightning. The 5Amp glass cartridge type fuse found burned and broken to pieces.
Some other damaged component/s will be there. It’s sure.
I did measure the voltage across the main filter capacitor [C628] 120MFD 450VDC; to check whether there is any residual static charge retains; because, if there is any voltage, my multi-meter will get damaged, when I try to measure the DC resistance across it. If there is any static voltage, we must fully discharge it before we measure resistance across its terminals.
No such static voltages detected.
I set the multi-meter to measure Ohms, and did measure the resistance across the main filter capacitor, mentioned above. I've attached photo of the SMPS board here.
The result was abnormal. Measured only less than one Ohms. There is a short circuit, at the mains rectifier section circuit itself.
Un-screwed out the SMPS board, to check which component/s are shorted / damaged.
(In this condition, the only way to check is by de-solder out the suspected component/s from the circuit board, and check it.]
I de-soldered out the mains rectifier stalk [marked here the position of it at the SMPS board]; and checked its DC resistance. It revealed that it has shorted junction inside; measuring a DC resistance less than 1 Ohms between its (+ve and (–ve) terminals. It has been damaged. A voltage spike caused by lightning has damaged it; dead short, causing the AC mains protection fuse to break into pieces.
Now it is sure that there will more damaged components. Without the rectifier stalk on board, I did measure the DC resistance across the mains filter capacitor; mentioned above. No short circuit detected now.
Checked the mains filter capacitor out from the circuit for it capacitance; using capacitance meter. It was OK. Measured 132MFD. Yet, it will be best to replace it with a new one, because it has already been hit by a high voltage spike. Even if it will work right now, might cause trouble with time.
Replaced the main rectifier stalk, and the mains filter capacitor. Double checked the circuit and made sure that there is no more short circuit.
Plugged the set to AC mains wall socket, and switched it ON.
I didn't heard any ‘relay click’ as this model sets will produce normally during power ON.
Checked the DC voltage across the mains filter capacitor again, and found normal as it should be.
On further checking, one among the three opto-couplers used was damaged {part number marked on board is PC803 (PC123)]. Its LED side open.
Replaced both the opto-couplers PC803 & PC801. Both are of same number (PC123).
Now switched on the set. OK.
There was no other fault with its main board. If were, I might have to return the set, as main board to this set is not available at local electronic spare part marked here.
THE ORIGINAL REMOTE CONTROL NUMBER TO THIS SET IS
N2QAYB 000399
Universal remote control set-up codes to Panasonic are:
0016 0032 0033 0049 0054 0075 0099 0101 0104 0107 0110 0119 0143 0151 0152 0161 0166 0207 0249 0304 0305 0306 0396 0420 0461 0611 0631 0633 0692