Panasonic TC-P55ST30 TV is not turning on.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

I just read the pdf tw2005 provided and according to that the problem is either with A board or the P board........I am all confused now.

Nothing to be confused about. get a multimeter and test for short circuit first at the SC board before looking at the A or P boards.

Or try disconnect SC2 and see blinks change,

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

Hi Guys,

So I opened up the TV and no obvious signs of anything burnt or shorted. So I disconnected SC20 connection and checked. I still go the 14 blinks. Then I disconnected both SC20 and SC2 connections and turned the tv back on. This time I got 8 blinks.

When I plug in the tv and press the power button(tv or remote) the light just stays on(NO Blinks), Then I press the power button on tv and the led starts blinking 14 times. According to the pdf(service manual) slide 83 I need to replace the P board.

Can anyone with experience in this please let me know if I am understanding it correctly, and that I need a new P board? Also what does it mean that the blinking changes to 8 blinks when I disconnect both SC2 and SC20?

Replies are greatly appreciated.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

Hi Guys,

So I opened up the TV and no obvious signs of anything burnt or shorted. So I disconnected SC20 connection and checked. I still go the 14 blinks. Then I disconnected both SC20 and SC2 connections and turned the tv back on. This time I got 8 blinks.

When I plug in the tv and press the power button(tv or remote) the light just stays on(NO Blinks), Then I press the power button on tv and the led starts blinking 14 times. According to the pdf(service manual) slide 83 I need to replace the P board.

Can anyone with experience in this please let me know if I am understanding it correctly, and that I need a new P board? Also what does it mean that the blinking changes to 8 blinks when I disconnect both SC2 and SC20?

Replies are greatly appreciated.

Did you try what I said before and check SC2 for short(using a meter)? When you pressed the button on the TV was it a single press or press and hold.

Sounds like shorted vsus at SC2 to me. 8 blinks is normal for SC disconnected however that's with SC20 disconnected.

Since with that alone removed you still had a 14, this means the vsus is still shorted, when SC2 is removed that short is cleared and the TV continues it's startup but then does not see the SC20 connected so 8 blinks it is.

Don't replace the PSU, I very much doubt it's at fault here.

On page 86 of that training guide, try this, hopefully it does as it says.

Disconnect SC2 SC20 C10 ,TV Stays On

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

Thanks tw2005, sorry for not being able to provide more information(or all at once).

I did check for short at SC2 and I think it is shorted. What I did was set the multimeter for continuity and then after disconnecting the SC2 I put one probe on one of the legs(where SC2 was connected) and the other probe on the other one. As soon as both probes touched multimeter made a continuous beep. Sorry, if this is not the right way for testing the short. Also, can you please explain how to test for short?

I also tried to test the resistance by turning the multimeter scale to ohms and selecting the 200Ω range. I did turn the multimeter off and on before the test once I touched both the probes to both the connections on the SC2 base I got the reading of .2 and if I increased the scale/range to anything else it showed 0.

I did disconnect all three SC2, SC20 and C10 but I still got the 8 blinks instead of TV staying on.

Also, when I plug the tv there is no light. Then I can either press the power button on remote or on the tv itself once and the light comes on(No blinks). At this point if I press the power button on remote or tv once like before nothing changes. So, I press the power button on tv for a few seconds(keep it pressed) and the blinking starts(14 times).

If my test for finding out if SC2 is shorted is correct, does the whole SC board is changed or the SC2 connector on the board can be changed?

Thanks for all the help and I apologize in advance if I am missing some information again(I have never worked on a circuit before, only did some work with them in school which was years ago)

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

OK, so SC is faulty, continuous beep and 0.2 is dead short.

Board will need replacement/repair, SD/SU ideally should be resistance checked.

The part number and revision should be on the board or a white sticker.

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

Can you please tell me how I can go about checking the resistance on SD and SU ?

Other than ShopJimmy.com is there any other place I can order parts from ?

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

VFO 2.2M

VSCN-F (TPSC1) 221K

5V_F 5.7M
see if you can find these in a service manual for this mode, block diagrams are good place.

Some guys have got these going just by replacing the dead transistors.

All I got time for now. Search board numbers and transistor number in bad caps there's info out there or someone else may dig it up for you

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

Thanks for all the help, I will post more in this thread.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

Actually, I had a look at SJ and seriously something must have changed. They have a truckload of these. Assuming yours is TC-P55St30, the Sc should have a sticker on it showing barcode showing 5351 (no revision after that) or TXNSC1PAUU.

You do need to pay attention to the revision when searching as they can use the same board in different sized panels and they are tailored for the panel version.

At the price they are I would consider getting 2. To my knowledge has 6 months wty, extra $6 for 1yr, extra $12 for 2yr.

Only problem with a 2yr wty is very good chance they'll have no stock when you need one, hence if you are keeping this for a while I'd take the opportunity to stock up.

I did this with my 2010, have spare set of buffers and some SC boards ready to go when it fails again which I expect it will.

There are a few on Ebay but I'd lean towards SJ because with the qty they have they'll essentially be brand new boards out of damaged in transit as opposed to used for most of the ebay stuff.

I've tried to make it easy for you with the pictures. resistance is from my 2010 model hoping to see something similar but last person to try this we got one board bad with obvious low ohms but the other was much higher than expected. Trying to avoid a shorted buffers possibly damaging the SC.

You'll see the pins run odd on one side, even on the other.

These are the instructions from my guide.

Procedure:
1.
Remove the 4 VFG screws from the SU and SD boards. (See picture to the next page (page 44).)
2.
Disconnect SC41, SC42, and SC46 from the SC board. Also remove the ribbon cable between the SU and SD boards (SU11/SD11). (See picture on the next page (Page 44).)
3.
Using the VF-Ground (VF_GND) as reference, measure the Vfo, VSCN-F, and 5V-F resistance’s on the SU and SD boards individually.The board is considered to be bad is a short circuit or a very low resistance reading is found on any of these lines.

The image shows using the blk lead from the meter on the test points, red on the gnd.

See how you go with that one.

Post the results and if keen, do one set with the leads one way, then flip them around and record the second set.

hopefully your meter is up to the task.

SU41
pin
2 , VF5V 5.7M

6, VSCN-F 221K

8, VFO 2.2M

SD42
pin
6, VF5V 5.7M

2, VSCN-F 221K

1, VFO 2.2M

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

thanks a log tv2005. I did not get a chance to work on it tonight but I did look at the sticker on SC board and the sticker has "5351 - U115901084 PA". I could not fine anything on SJ with this number. But I did find this
http://www.shopjimmy.com/panasonic-t...u-sc-board.htm

It was the first item listed in the search result for 5351 and the description says it is for TC55ST30. It is 5351 and PA but the middle part on the sticker doesn't match.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

thanks a log tv2005. I did not get a chance to work on it tonight but I did look at the sticker on SC board and the sticker has "5351 - U115901084 PA". I could not fine anything on SJ with this number. But I did find this
http://www.shopjimmy.com/panasonic-t...u-sc-board.htm

It was the first item listed in the search result for 5351 and the description says it is for TC55ST30. It is 5351 and PA but the middle part on the sticker doesn't match.

yep, so that's the right one, TNPA5351 no suffix/rev

[Shankerd]

Re: Panasonic TC-P55ST30 TV is not turning on.

Thinking again about how much time I am able to put into it and how easy/difficult it would be for me to figure out if SD and SU are good, I think I am just going to replace all three boards. SJ doesn't have either SD(5341 PA) or the SU(5340 PA). Both are out of stock. Is ebay the only other place I can look for these boards?

[Gary o]

Re: Panasonic TC-P55ST30 TV is not turning on.

I have no lights and I did the repairs. But it still blows the fuse !!,!!,,

I hope you guys can help I'm lost I had the same problem as you guys and I did the repairs that you did. But there more after I got all done I pluged it back togather and it poped the 401 so I repaired it and check the rest then i unplugged all the connections, I pluged one at a time and all good intell I got the blue plugs that come from board k68297 once I pluged pop!!!

I'm i missing something

[pkwasson]

Re: Panasonic TC-P55ST30 TV is not turning on.

tw2005,

Thanks for the great direction. I was able to fix my TV by following your direction.

Only $60 to get a new board.

thanks again

[suceava20]

Re: Panasonic TC-P55ST30 TV is not turning on.

Solid Light > then > 14 power led's blinks = SC Board Defective. (Had this on a TC-P50S30)

Got a SC Board from alltvparts.com

[planetska]

Re: Panasonic TC-P55ST30 TV is not turning on.

Same issue as others. Solid red light -> hold power button and it switches to 14 blinks. Checked for short circuit on SC board and switched it out. Fixed the problem for $60 from ShopJimmy.com. Thanks!

[sbpb]

Re: Panasonic TC-P55ST30 TV is not turning on.

Thinking again about how much time I am able to put into it and how easy/difficult it would be for me to figure out if SD and SU are good, I think I am just going to replace all three boards. SJ doesn't have either SD(5341 PA) or the SU(5340 PA). Both are out of stock. Is ebay the only other place I can look for these boards?

Just wondering if Shankerd was able to fix his TV problem, and what he ended up replacing. I developed exactly the same problem today on my 55ST30. Noise, then picture went off and power LED stayed on. When I unplug and plug the TV back in, the power LED comes on and stays on. If I press the power button on the TV, I get 14 blinks. TV turns off only by unplugging.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

Just wondering if Shankerd was able to fix his TV problem, and what he ended up replacing. I developed exactly the same problem today on my 55ST30. Noise, then picture went off and power LED stayed on. When I unplug and plug the TV back in, the power LED comes on and stays on. If I press the power button on the TV, I get 14 blinks. TV turns off only by unplugging.

Sounds like the typical shorted Sc board, buffers would need to be checked before replacement and watch out for signs of loose screws on the SC,Sd,SU and SS boards.

pretty sure there's a 14 blink thread for this model / series or gt30 you could search and read.

[PBSB]

Re: Panasonic TC-P55ST30 TV is not turning on.

Actually, I had a look at SJ and seriously something must have changed. They have a truckload of these. Assuming yours is TC-P55St30, the Sc should have a sticker on it showing barcode showing 5351 (no revision after that) or TXNSC1PAUU.

You do need to pay attention to the revision when searching as they can use the same board in different sized panels and they are tailored for the panel version.

At the price they are I would consider getting 2. To my knowledge has 6 months wty, extra $6 for 1yr, extra $12 for 2yr.

Only problem with a 2yr wty is very good chance they'll have no stock when you need one, hence if you are keeping this for a while I'd take the opportunity to stock up.

I did this with my 2010, have spare set of buffers and some SC boards ready to go when it fails again which I expect it will.

There are a few on Ebay but I'd lean towards SJ because with the qty they have they'll essentially be brand new boards out of damaged in transit as opposed to used for most of the ebay stuff.

I've tried to make it easy for you with the pictures. resistance is from my 2010 model hoping to see something similar but last person to try this we got one board bad with obvious low ohms but the other was much higher than expected. Trying to avoid a shorted buffers possibly damaging the SC.

You'll see the pins run odd on one side, even on the other.

These are the instructions from my guide.

Procedure:
1.
Remove the 4 VFG screws from the SU and SD boards. (See picture to the next page (page 44).)
2.
Disconnect SC41, SC42, and SC46 from the SC board. Also remove the ribbon cable between the SU and SD boards (SU11/SD11). (See picture on the next page (Page 44).)
3.
Using the VF-Ground (VF_GND) as reference, measure the Vfo, VSCN-F, and 5V-F resistance's on the SU and SD boards individually.The board is considered to be bad is a short circuit or a very low resistance reading is found on any of these lines.

The image shows using the blk lead from the meter on the test points, red on the gnd.

See how you go with that one.

Post the results and if keen, do one set with the leads one way, then flip them around and record the second set.

hopefully your meter is up to the task.

SU41
pin
2 , VF5V 5.7M

6, VSCN-F 221K

8, VFO 2.2M

SD42
pin
6, VF5V 5.7M

2, VSCN-F 221K

1, VFO 2.2M

My SU board is a 5340 (for 55ST30). The SC board had a short and I got it fixed. Then I checked the SU board, and it has a short at pin 8 on SU41. SD42 seems to be fine, and the other pins on su41 also seem to be fine. Are the tests for 5340 the same as for 5343, so short on pin 8 means bad buffer board? The SC board had a short at SC2 but no sign of arcing at the screws, and they seemed to be fairly tight when I took them out, so I am wondering if the bad buffer caused the SC board to fail.

Thanks.

[tw2005]

Re: Panasonic TC-P55ST30 TV is not turning on.

Pin 8 is Vfo, if Vfo is short to the Vfg ( gnd) plates on that buffer board, board is shorted.

Shorted buffer can take out SC and Sc may have also blown the buffer.

just had a quick look and very depressing how you can't get parts for these late model units. Modus show $57 for SU repair which is cheap compared to $140 on Ebay, Wow!