Panasonic TC-P50G10 10 blink code

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Tom we gonna be able to dig into this board? Are the odds the fault is in this board? I see someone on ebay rebuilds them I wonder what goes bad?

[tom66]

Re: Panasonic TC-P50G10 10 blink code

I've got a 2.5hr exam tomorrow. I'll talk tomorrow if I've got some free time, but right now I'm focusing on getting a good night's sleep. In the meantime, I suggest you brush up on your schematic knowledge and trace where the individual signals are going. The LOW signals (<1V) are definitely bad. Find SUB9V, SUB5V etc on the schematic. Check those test points for 9V & 5V, and any others. If you hit a DC-DC converter or LDO, check the input voltages, enable signals, diodes, FETs, etc. You will likely find the MICOM turns one supply on after another and tests each until there is a failure (or it passes) and in which case only one supply is bad, it just hasn't turned on the rest yet. In which case, a high ENABLE signal on that particular supply but no output would be indicative of a fault with that particular portion.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Ok will do my best good luck on your exam

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Well Tom finding this page helps I was studying the actual schematic, any tips on isolating the faulty line I haven't had a chance to check anything yet, I am intending on making sure the F15V is present from PS board first then going from there, but those other lines go in a hundred directions Id like to isolate which one it is but I think Im gonna have to pull some components to do so..

[tom66]

Re: Panasonic TC-P50G10 10 blink code

You just need to find the 5V, 9V, etc. SMPS on the A board, do you know what to look for?

This is a buck converter.
http://www.maximintegrated.com/image...DI120Fig01.gif

Sometimes the bottom diode is replaced with another FET. Part # of controller IC can vary.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

D5573 shows shorted in circuit as does C5420, what's the best way to isolate, they are VERY small components??

[tom66]

Re: Panasonic TC-P50G10 10 blink code

I would remove the diode, see if SUB9V rises, if not, replace it (you can move it so that it is soldered on only one pad), then repeat the same with the capacitor. Maybe the regulator IC has an output-ground short?

[tw2005]

Re: Panasonic TC-P50G10 10 blink code

Maybe remove IC5401 BA178M09FP-E2, and check out of cct if gnd-out is also short as it's the same measuring point as the cap and the zener.

Similar cct design and 10 blink, resolved with A board, in this post, don't know if the fault finding will help any? the zener is mentioned .

https://www.badcaps.net/forum/showth...t=21115&page=3

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

I thought I found the problem but after removing the diode, cap and IC one at a time, none are shorted out of circuit and the short remains between ground and output pads of IC. The diodes 5521 and 5522 test good. I tested input and was getting about 14.5v but no output.

Does that mean short is further down the SUB9V line?

[tom66]

Re: Panasonic TC-P50G10 10 blink code

Probably.
If you have a current limited power supply and a can of freeze spray you can warm up the failed component and this will be visible in the freeze spray.

Set the current limited power supply to 50~100mA, or use an 82 to 220 ohm resistor in series with a 9V power supply.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Thats a great idea. I dont have a power supply but can I do this with a 9V battery? Can you make a quick diagram to show me how it would be wired? Use some ground point on the main board and inject the + at the output leg of that IC above? Thanks!

[tom66]

Re: Panasonic TC-P50G10 10 blink code

Yes, a 9V battery should be fine, but you MUST use the 100 ohm resistor, and the resistor will get hot, so I recommend using a 2 or 3W resistor. As far as explanations go, the TV should be off, the negative of the battery can go to the chassis or any good ground, and the positive goes through the 100 ohm resistor to SUB9V. Limit time to 10 seconds maximum every 30 seconds to avoid damaging anything.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

OK I had to go to Radio Shack for the resistor, my choices there were 100 ohm 1 Watt and 100 Ohm 10 Watt (cement type) so I picked up a few of each, which one would be better?

[tom66]

Re: Panasonic TC-P50G10 10 blink code

100 ohm 10 watt, as long as the leads are axial (on different ends.) If not, four 100 ohm 1W can be made into a 100 ohm 4W.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Didn't have much luck with this technique, I went thru 1 1/2 cans of freeze spray, everything defrosts so quick here in FL! But nothing got noticeably hot unfortunately. Maybe one of the ICs under heatsink?

[tom66]

Re: Panasonic TC-P50G10 10 blink code

Is your battery fresh?

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

Yes it was unused and had 9V. Wonder if I should put the board in the freezer for like 20 mins first to give the freeze spray a head start, it just doesn't stay frosty for more than a few seconds...?

[tom66]

Re: Panasonic TC-P50G10 10 blink code

Maybe. I've had no problem with freeze spray staying frosty for 5 minutes+.

[kevinm34232]

Re: Panasonic TC-P50G10 10 blink code

How long are you spraying for? Are you spraying the whole board at once? Cans dont last long and cost like $15.

[tom66]

Re: Panasonic TC-P50G10 10 blink code

Cans here cost £1 for 200ml, so I can afford to liberally use the stuff. Then again, I am using canned air, not freeze spray, when upside down it does nearly the same thing. Maybe better because it stays frosty for longer.