Panasonic TC-P50S1 with 10 blinks

[jet]

Hi,

I have a Panasonic TC-P50S1 with 10 blinks SOS. I have attached pictures and some of the board part numbers are:

P Board = ETX2MM747AFK
SS = TNPA478
SU = TNPA4782


Am I lucky enough that the P-Board is subject to the thermal fuse failure? Here is to hoping I don't have to get into the SS board.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

I have added pictures of the A board because the manual say that is the board to look at.

[tom66]

Re: Panasonic TC-P50S1 with 10 blinks

Your pictures need to be clearer and in focus, there is a bit of blur making it hard to see some parts. I recall a fuse can fail on these A boards causing 10 blinks. Also check the SD card slot for coins, damage and debris.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

More hopefully clearer pictures.

[tom66]

Re: Panasonic TC-P50S1 with 10 blinks

See slide 31



Can you see TPSOS on the A-board?

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

Just looking for it now, where about on the A board is it?

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

TPSOS appears to be labled TP3500 on the A board. It is +5VDC. Pin 7-8-9, P board comes on for 1/2 second or so at 14.65VDC. TP3500 stays at 5VD on.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

First off sorry for not getting back to this thread. My grand kids came over last weekend and I had to move the TV of the test bench... our bed in the spare bedroom LOL.

Anyway after long work week I now have some time.

I tested the TPSOS under the following condition. AC power not connected, then connect AC power. When AC is connect but TV OFF I get a reading of 3.03VDC on TPSOS (not a typo 3.03VDC reading not 3.30VDC).

When power On button pressed I hear the relay click and I get 0.0VD for a 1/2 second or so then the 3.03VDC comes back and LED blinks 10 times.

[tom66]

Re: Panasonic TC-P50S1 with 10 blinks

OK, so HIGH is SOS.

This will probably be an A board fault.

Try locating F15V on the power board connector and checking that during SOS, from slide 31:

Find out if 15V is output at pin 7,8,or 9 of connector P6 of the P board. If no voltage is output, the P board may be defective.

If the F_STB_15V voltage is OK, it’s likely that the A board is defective.

BT30V, SUB5V and SUB9V are generated by the A board and the F15V is generated by the P board, so if it is not F15V, it is the A board. If F15V is bad it could be a short on other boards loading it down or a P board fault.

If you have experience with chasing down faults on complex Panasonic A boards speak now. Otherwise, I would suggest (if F15V is okay) that you buy a new A board.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

The 15VDC comes on when the power button is first pressed until the relay clicks and then the 15VDC disappears. So something is loading it I think.

What about the fact the the 3.3VDC is only 3.03VDC?

[tom66]

Re: Panasonic TC-P50S1 with 10 blinks

3.03VDC is fine. It's passing through a series transistor, so there is some voltage drop.

I'd be inclined to unplug different boards (SC, SS, maybe other boards if they are connected to 15V) to see if the 15V behaves differently.

Otherwise, we can have a look at the signal going into this transistor and try to trace which rail is causing the fault.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

So what is the order of disconnecting the boards SC, SS and what cables do I take off power and the ribbon (signals) cable?

I will look at the manual too.

Thanks, Jet

[tom66]

Re: Panasonic TC-P50S1 with 10 blinks

So what is the order of disconnecting the boards SC, SS and what cables do I take off power and the ribbon (signals) cable?

I will look at the manual too.

Thanks, Jet

Just try one board at a time, the exact order isn't too critical. Unplug data cables (flat ribbon) between A board and SC/SS/etc as well as power.

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

Ok so I finally got back to testing this TV. I looked at the manual and it's not clear about the order of disconnecting SC/SS boards. Like what ribbon cable is for what board?

Anyway when I have all three ribbon cables disconnected from the A board and power disconnected from the SC/SS the fault clears. That is the red power LED come on solid no blinks.

How do I narrow down the boards to figure out if it SC/SS?

[jet]

Re: Panasonic TC-P50S1 with 10 blinks

Bump... How do I isolate the SC/SS boards from the A board, separately. When both are disconnected the PSU comes on. Want to narrow it down.

TIA