Panasonic TC-P55GT30 will not turn on, seven blinks from LED

[Ben09]

Hi,

I just joined the forum to get help on this issue. My Panasonic TC-P55GT30 was on and working perfectly a little over a week ago. When I went into the other room and came back, it was shut off. When I unplugged it and plugged it back in, I got the seven blinks from the LED. I unplugged it for 24 hours, plugged it back in and got the seven blinks again. I chatted with a Panasonic rep online, who told me to hold down the power button while plugging it in. This also did not work.

I ordered the SC card repair kit from ShopJimmy and my father in law is currently looking at the card. I wasn't sure about the different tests but he's going to see if there are any shorts in the resistors etc.

Thanks in advance for any advice you can give.

[JeffJ]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Its definitely a SC issue, I own this same model. Repaired the SC my self as well.

Also be sure to test the Buffer boards in case they popped with the SC.

There is a thread with hundreds of posts in regards to this issue on similar and same model.

[Terryfictv]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Kits often contain more parts than needed for a solid repair. It is best to isolate which parts are shorted and which ones are open,if any.First, identify the SC part number including the suffix. TNPA5335xx ( no suffix, BA, or BK )Look on the white sticker.

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Thanks for the replies! I'm glad to know it is the SC board that needs repairing. I read about how to test with a multimeter if the SU or SD board is failing. I'll make sure to do that before I put the SC back in.

Also, thanks Terry for that idea. I will have him check those before replacing.

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

When I get the board back, what's the best way to test the SU and SD boards for resistance?

[Moreno83]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

https://www.youtube.com/watch?v=k0EZHBr4dMQ , This is how you test buffer boards.

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

https://www.youtube.com/watch?v=k0EZHBr4dMQ , This is how you test buffer boards.

Thank you! I'll test it tonight. I assume it will still work if I just remove the connectors between the SU and SD boards and obviously not have the SC in?

[Moreno83]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Hmm not sure! Never tested it inside the tv. Safest is pulling both boards from the tv and test them like that. ( its save to do it now , don't need to wait for SC board ).

Black to ground , red to the pins and if you hear a beep on the pins then it has a short. Watch out that you don't touch any other parts on the board besides the pins. You could accidentally touch a part thats connected to ground with causes a beep , it will make you think the board is short

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Got the SC board back today. Now it doesn't power on and has 6 blinks. Diagnosis YouTube with Shop Jimmy says it's the power board since we get no voltages from the two places to check on the SC board when powered on. So I'm at a crossroads. I could pay another $100 and get the p board and maybe get another couple years out of it. Has anyone repaired them and had them last? I want to know if it's worth it to repair.

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Or has anyone had experience changing the power cord or power supply instead? I wouldn't think it would be those since at least there are signs of life.

[Moreno83]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Power cord wont die. According to the service manual :

The energy recovery circuit and Vscan are monitored in the SC board. Failure of any
these 2 circuits triggers the SOS6 line causing the unit toshut down and the power LED
to blink 6 times.
Under normal operation, the output voltage (MID) of the “Energy Recovery” circuit ranges
between 68V and 138V. If the voltage drops below 67V or increases above 139V, the
error detect circuit (IC16581) is triggered. This causes a high to be output to pin 15 of
connector SC20.
Pin 15 of SC20 (SOS6-SC1) also goes high,if the Vscan generating circuit fails.
The voltage from SC20 is connected to the Peaks – LDA3 (IC8000) on the A board via
the DC level shifter section of the ASIC (Application Specific) IC (IC5000)
If this voltage goes high, the TV shuts down and the power LED blinks 6 times.
This condition is normally caused by a defective SC, A, or P board. (SC>A>P).
6 blinks can also be caused by open connection between the C boards and open
connection between any of the C boardand the A board.


Did you order the right repair kit? You need the repair kit with most parts as its not only the fets that get shorted.

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

We actually ended up ordering a different one on ebay from a good seller and sending the old one back so I know the card is working. Is the A board more suspect than the P board? I checked these two places on the SC card where one is supposed to read 15 volts and the othe 5 volts, both show 0 volts. That is supposed to indicate it's the power supply.

[tw2005]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

did you repair it or someone else? I'd be inclined to think SC with 6 blinks

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

did you repair it or someone else? I'd be inclined to think SC with 6 blinks

Someone else. An ebay seller who had 99% feedback and sold other TV parts.

[flocko]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Recheck SC boards for short across SC2, also when checking SU/SD for faulty buffer ICs you use floating ground TP VFG not common ground as you were told in post #8, so I would check these again.

[tw2005]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

Recheck SC boards for short across SC2, also when checking SU/SD for faulty buffer ICs you use floating ground TP VFG not common ground as you were told in post #8, so I would check these again.

definitely do this, reading the thread I wonder if the SC was checked properly and , no, 7 blinks is not always / definitely SC as the buffers short on these too and there's been a number of cases where the SC was good , buffers bad.

Safest place to send boards to is moduslinkpts

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

definitely do this, reading the thread I wonder if the SC was checked properly and , no, 7 blinks is not always / definitely SC as the buffers short on these too and there's been a number of cases where the SC was good , buffers bad.

Safest place to send boards to is moduslinkpts

TV is getting 6 blink error code after replacing SC instead of 7. I replaced the power board and sub power board with no difference. I will be sending those back to that seller. Could 6 blinks still mean SU or SD? Or is it the A board?

According to the service guide, it says it's either the SC board or A-SC FPC whatever that means. I couldn't find anything on Google about thst.

[tw2005]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

TV is getting 6 blink error code after replacing SC instead of 7. I replaced the power board and sub power board with no difference. I will be sending those back to that seller. Could 6 blinks still mean SU or SD? Or is it the A board?

According to the service guide, it says it's either the SC board or A-SC FPC whatever that means. I couldn't find anything on Google about thst.

Your confused, so am I . When i said I'd go down the path of SC fault that's what i hoped you'd do and not waste time and money elsewhere.

6 blinks is one of those one that for me spell SC where 7 could be Sc or sd/su.

To help you understand A-SC FPC that is the flat pack cable A-SC, AKA SC20

I would contact the provider of the SC board and inform them you suspect the SC is faulty and giving 6 blink code.

There's probably a way to isolate enough boards to fire this up to check P and A pass but I'd be inclined to either see if another SC can be sent or if you know what you're doing probe the SC transistors and see if anything is shorted.

Do you have an image of the current board for us to see. Which seller did the board?

[tw2005]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

have you seen this flowchart?

[Ben09]

Re: Panasonic TC-P55GT30 will not turn on, seven blinks from LED

According to the flowchart, after disconnecting SC20 it gives 8 blinks. So I will contact the seller and have them send me a different one.