I was given the TV by a relative who had already put it outside in the rain ready for landfill, luckily it was screen side up & at an angle so I was able to fully dry it out (I think). Immediately on applying power the standby light flashes very fast (16 times I think) then goes steady for several seconds, during which time the screen flashes, trying to start, first showing four blank screens then a pause followed by another blank screen & then three screens on which I can see “No Signal” then another pause followed by another blank screen & three more “No Signal” screens. The standby light then turns red and starts flashing once every 4 seconds. That's how it stays and is non- responsive to the remote. From applying power to first red light is 10 seconds.
Finding no legend on the power board, and initially being unable to locate a service manual, I realised fault finding would be problematic. I foolishly took the rapid flashing as the blink codes I'd found mentioned on the net so, as it wasn't a lot of money, I purchased an "A Board" (TNP4G548) off EBay. Unfortunately this made no difference.
I then went back to Google and eventually located a SM from:-
(It's for a TX-L42B6E (“E” at end) which is the European model)
Armed with the manual I measured the voltages:-
Connector P3
-----------------
8 24v Reads 24V for 10 seconds then falls to 0
7 24v Reads 24v for 10 seconds then falls to 0
6 GND OK
5 GND OK
4 BL_SOS Rises to 3.66V three times the settles at 0.88V
3 BL_ON Rises to 3.66V three times then settles at 0V
2 ???? Not Connected
1 PWM1 3.46V falling to 0V, then 3.46V falls to 1.1V then 3.00 falls to 1.0V then 0.08V
Connector P2
-----------------
14 GND OK
13 BL-PWM1 3.45V Three times then settles at 0.08
12 BL_ON 3.15V Three times then falls to 0
11 BL_SOS 3.66V Three times then falls to 0.88
10 KEY 3.25V
9 POWER-ON 3.25V
8 SUB-ON 2V for 10 seconds then 0V
7 GND OK
6 5vs 5.23V
5 GND OK
4 (FUNC ON) Not Connected
3 16V Not Connected
2 16V 15.43V for 10 seconds then falls to 0
1 16V 15.43V for 10 seconds then falls to 0
The manual on P22 says the single blink code means "BL_SOS - A Board Panel" (is that "A Board" or "Panel" meaning the screen).
I've not included any photos yet since I can't see any damage and, having the SM, I thought they might not be required.
Not wanting to pre-empt anything but I did find this on EBay:-
http://www.ebay.co.uk/itm/Panasonic-...8AAOSwdvpWDr2G
Which says it's a genuine Panasonic repair kit for the inverter board TNP4G549 which has:-
2x Transistor Q9804, Q9802 (Panasonic improved part) - Both B1CFRM000028
2x Capacitors C9807, C9812 (Panasonic improved part) - changed from 1nF to 2.2nF
It does say this is for two 50 inch versions of my TV (TXL50B6B & TXL50B6E) which have “No picture and sound, sometimes LED flashes 3 times”. It also says it only affects models prior to serial number 3330003 whereas mine is 3350550.
Before I noticed the serial number caveat I did try testing the two transistors mentioned whilst in circuit (never having tested transistors before). I read that you should select diode on the DMM so I did that (a diode symbol and "2K" on my meter). Using the guide on this site for “Troubleshooting 2 seconds to black - Testing mosfet.txt", I assumed the single connection at the top to be (1) and the other two connections (2) & (3) from left to right. I then got readings:-
(1) to (2) - 1.781 ohms on both (Black probe on (1))
(1) to (3) - 0.559 ohms on both (Ditto)
(2) to (3) - .869 on one & .868 on the other (Black probe on (2))
I've since read that maybe I shouldn't test Mosfets like this but I've put the board back in the TV and it's as it was. So no harm done, fingers crossed.
I hope I've provided enough information to enable someone to kindly help me.
Thank you
Graham
Finding no legend on the power board, and initially being unable to locate a service manual, I realised fault finding would be problematic. I foolishly took the rapid flashing as the blink codes I'd found mentioned on the net so, as it wasn't a lot of money, I purchased an "A Board" (TNP4G548) off EBay. Unfortunately this made no difference.
I then went back to Google and eventually located a SM from:-
(It's for a TX-L42B6E (“E” at end) which is the European model)
Armed with the manual I measured the voltages:-
Connector P3
-----------------
8 24v Reads 24V for 10 seconds then falls to 0
7 24v Reads 24v for 10 seconds then falls to 0
6 GND OK
5 GND OK
4 BL_SOS Rises to 3.66V three times the settles at 0.88V
3 BL_ON Rises to 3.66V three times then settles at 0V
2 ???? Not Connected
1 PWM1 3.46V falling to 0V, then 3.46V falls to 1.1V then 3.00 falls to 1.0V then 0.08V
Connector P2
-----------------
14 GND OK
13 BL-PWM1 3.45V Three times then settles at 0.08
12 BL_ON 3.15V Three times then falls to 0
11 BL_SOS 3.66V Three times then falls to 0.88
10 KEY 3.25V
9 POWER-ON 3.25V
8 SUB-ON 2V for 10 seconds then 0V
7 GND OK
6 5vs 5.23V
5 GND OK
4 (FUNC ON) Not Connected
3 16V Not Connected
2 16V 15.43V for 10 seconds then falls to 0
1 16V 15.43V for 10 seconds then falls to 0
The manual on P22 says the single blink code means "BL_SOS - A Board Panel" (is that "A Board" or "Panel" meaning the screen).
I've not included any photos yet since I can't see any damage and, having the SM, I thought they might not be required.
Not wanting to pre-empt anything but I did find this on EBay:-
http://www.ebay.co.uk/itm/Panasonic-...8AAOSwdvpWDr2G
Which says it's a genuine Panasonic repair kit for the inverter board TNP4G549 which has:-
2x Transistor Q9804, Q9802 (Panasonic improved part) - Both B1CFRM000028
2x Capacitors C9807, C9812 (Panasonic improved part) - changed from 1nF to 2.2nF
It does say this is for two 50 inch versions of my TV (TXL50B6B & TXL50B6E) which have “No picture and sound, sometimes LED flashes 3 times”. It also says it only affects models prior to serial number 3330003 whereas mine is 3350550.
Before I noticed the serial number caveat I did try testing the two transistors mentioned whilst in circuit (never having tested transistors before). I read that you should select diode on the DMM so I did that (a diode symbol and "2K" on my meter). Using the guide on this site for “Troubleshooting 2 seconds to black - Testing mosfet.txt", I assumed the single connection at the top to be (1) and the other two connections (2) & (3) from left to right. I then got readings:-
(1) to (2) - 1.781 ohms on both (Black probe on (1))
(1) to (3) - 0.559 ohms on both (Ditto)
(2) to (3) - .869 on one & .868 on the other (Black probe on (2))
I've since read that maybe I shouldn't test Mosfets like this but I've put the board back in the TV and it's as it was. So no harm done, fingers crossed.
I hope I've provided enough information to enable someone to kindly help me.
Thank you
Graham
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