Panasonic TX-p42s20b keeps clicking

[homerclone]

Hi I have a Panasonic TX-P42S20B. when I turn it on all I get is a blank screen and the relay just keeps clicking all the time . No set pattern to green flashing light it just flashes really fast every time the relay clicking. so not set number of flashes if that makes sence can post video if it helps.

Thanks for your time Mark

[Hamie]

Re: Panasonic TX-p42s20b keeps clicking

There are posters here who are superb at repairing Panasonics.

The first thing they will ask for are pictures of all the circuit boards.

[homerclone]

Re: Panasonic TX-p42s20b keeps clicking

link to video hope it helps
https://www.youtube.com/watch?v=VKco...ature=youtu.be

[tw2005]

Re: Panasonic TX-p42s20b keeps clicking

I'm thinking it'll be A-board and it does look like it attempts to spit out an error blink but fails to do that too which also suggests A-board.

but try this first as the SC board in these can fail and short out the P-board.

Disconnect SC2,,SS11,P35 and 3 white ribbons at the A-board and power on. If it manages to complete the startup and go solid green then A & P are ok, check for shorted SC or SS.

Don't reconnect sc2,ss11 and particularly P35 straight away after a power cycle, there'll be residual voltage present and spiking the panel with P35 can damage the Panel beyond repair. Either check these with a meter first or give it 5-10mins to bleed off. looking at 200v at sc,ss boards and about 50-60v at p35 when running.

If it's the same Then A or P. We have similar models here and 2 common failures I've noticed are Sc and A board. A board seems to run very hot and main processor BGA solders I suspect fracture with heat stress.

Could try warming the A board up and see if any changes occur

[homerclone]

Re: Panasonic TX-p42s20b keeps clicking

Thanks for the reply and sorry been away so I'm just going to try you suggestion.
Thanks

[homerclone]

Re: Panasonic TX-p42s20b keeps clicking

hi tw2005 I get the same problem when I do the following -
(Disconnect SC2,,SS11,P35 and 3 white ribbons at the A-board and power on. If it manages to complete the startup and go solid green then A & P are ok, check for shorted SC or SS)
Do you suspect the a board or p board for this fault?
cheers for your time
Mark

[tw2005]

Re: Panasonic TX-p42s20b keeps clicking

hi tw2005 I get the same problem when I do the following -
(Disconnect SC2,,SS11,P35 and 3 white ribbons at the A-board and power on. If it manages to complete the startup and go solid green then A & P are ok, check for shorted SC or SS)
Do you suspect the a board or p board for this fault?
cheers for your time
Mark

it'll be A board I expect but if someone knows how to force the PSU to stay on with all the other boards off, may be worth testing to see all the voltages are stable but a problem with the A board csn do this, I've had endless clicking / reboots and was an issue with the 48 pin flash ic but yours is quitting and cycling much more erratic than what mine did

[ljintexas]

Re: Panasonic TX-p42s20b keeps clicking

P board is easy to verify..TW2005 knows these babies. He helped me with a 50" which still looks better than any new tv today!

[homerclone]

Re: Panasonic TX-p42s20b keeps clicking

Ok tw2005 I will try a board and update you all. thanks for your time
:-)
Mark

[Andrew F. Ali]

Re: Panasonic TX-p42s20b keeps clicking

Here is a method to self test a Panasonic Plasma Power Board:
1. Disconnect all the connectors to the PSU Board, except the AC input.
2. On connector P7 connect a1Kohm resistor from Pin 1 (STBY 5V) to Pin 5 (F_STBY_ON) and another 1Kohm resistor from Pin 1 to Pin 7 (Panel _Main_ON)
3. Using a piece of wire solder connect Pin 1 and Pin 3 on connector P35
4 Connect a light bulb tool across connector P2 (Vsus voltage and Gnd)
5 Plug in the AC supply, If the PSU Bd is good the light bulbs will light up.
6. Measure the Vdc across connector P2-It should give you the Vsus voltage approx. 192Vdc.
The light bulb tool is two(2) 220V 100W Light bulbs connected in series
Quick and easy method to self-test Plasma PSU Bds.
Regards