Panasonic TH-50PX75U Plasma 10 blinks?

[tom66]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Try a dim image then slowly up brightness, see if Vsus drops out too low. It might be set too high, above panel rating, causing over-current...

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

I can't get it to come on at all right now. I just went through this troubleshooting diagram and it definitely points to the P Board though.

The weird thing is it seemed to work for a few days until I messed with the modules MC201 and 301 (maybe coincidence). Could it be the bad ICs TEA1610T?

[tom66]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Try checking the voltage at the capacitors again, same 0V on one? It could be a bad IC.

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

So MC301 still the same, 12V in standby and drops out once power button is pressed and 10 blink code starts.

MC201 is opposite, nothing in standby and when power button is pressed voltage rises for a split second then drops down and tv clicks off.

I'm guessing the 10 blinks is coming from the missing 15V to A board? The 15V does come up for a split second as well then drops off.

Also VSUS comes up to 195V briefly and then drops off immediately.

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

I found a thread on another forum with this post:
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I have just recently fixed a 10 blink, and now a 2 blink problem.
The 10 blink was the MC301 module (more later).
The 2 blink was the MC201 module.

The TEA1611 chip on those stand up boards wants 13.5 volts to pin 13 to start up. If the chip is leaking and requires too much current, it won't get to 13.5v.

On the 10 blink failure, the sm cap going to pin 13 was leaking. It was a 1uf.
On the 2 blink failure, it is the actual chip that is leaking (TEA1611).

Here is an easy test.
With the board on the bench and the big caps discharged, apply a low current supply (less than 2ma is needed) to pin 12 of the module (MC201/301). The negative side of the power supply used should be connected to the hot common. Those 3 white .1ohm resistors in a row is an easy spot to attach.

Increase the voltage and watch pin 7 on the module. Pin 7 will track the input voltage. Before you hit 15v, the module will turn on if good (s/b less than 14.5v). Pin 7 will output a square wave. It may come on as you increase the voltage further (don't go above 20v). But, the higher the voltage needed, the worse the module is.

I can give more info on the module if needed.
Hope this helps!

P.S. An easy temporary test is to attach a 4.7kohm resistor from pin 12 on the module to pin 13 on the chip (TEA1611) or to the cap that goes to pin 13. That should give enough extra current/voltage to get the chip started.
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I tried this with a 3.3kohm resistor, pin 12 on the module has about 17V, but when connected to VDD pin of TEA IC it throws the 10 blink code immediately.

I know I don't have the 13.5V so I guess I will try a new chip? Are the 10uF 50V caps I used possibly an issue?

[tom66]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

It is possible the caps are too large, preventing VDD from rising quickly enough. It is also possible the IC is defective.

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Well I ordered the new ICs.

So to make sure Im on the right path, the 15V that Im supposed to have I don't have until the TV starts the 10 blinks, and it shows 15V for a split second.

Would I have the 15V immediately after the power button is pressed, or could it be something else?

[tom66]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

There are two 15V supplies, a "15Vs" which is active almost immediately after the relays click, and a "15Vc" which is active a few seconds before a typical 10 blinks fault. They are both generated by the same supply but switched individually.

The Vsus will usually fire up if both supplies are OK. If all is well, a couple seconds later Vda rises, then panel glows, and TV displays picture.

If Vsus doesn't rise, then the PSU will shut down cutting 15Vc/15Vs -- main board sees this and mis-detects fault as SOS10 (due to 15V failure)

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Well now it's blinking 10x before power button pressed probably due to the last spark I caused trying to TS. Ughh

[kevinm34232]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Ok what did I do here?

I've lost the voltage on pin 12 of the MC301 module, however it is there on MC201, and looks to be the same line with nothing in between. Whatever I touched it also blew F201 which I replaced.

[tom66]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Cracked solder joint on that pin? If fuse blew, transistors might have gone too, make sure to test them.

[Pierre Kardan]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Did you ever find the problem?

[rowly747]

Re: Panasonic TH-50PX75U Plasma 10 blinks?

Would be great if kevinm34232 could update whether he fixed this in the end i also have a suspected P board problem. 10 red flashes before touching the power button.