Panasonic TC-P50S30 14 blinks - 7 blinks

[srs]

My neighbor gave me a Panasonic TC-P50S30 that stopped working. When I plugged it in and then hold down the power button, I get 14 blinks on the power LED.

Following the advice on this board; I disconnected the SC board from the power board and got 7 blinks. That means the P, SS, and A boards are good and that the SC, SD, and SU boards are suspect. The power pins on SC are shorted, so that is definitely bad. I disconnected SD and SU to check if they are shorted by checking SD42 (pins 1, 2 & 6 to gnd) and SU41 (pins 2, 6 & 8 to gnd). I have a cheap multimeter which maxes out at 2M ohms, and all six pins are over range. Does that mean SD and SU are probably good?

I guess my next step is to get shopjimmys repair kit and see what happens. My backup plan is to have moduslink repair it if I can't. Do I have it pretty much right?

Thanks,
Steve

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

My neighbor gave me a Panasonic TC-P50S30 that stopped working. When I plugged it in and then hold down the power button, I get 14 blinks on the power LED.

Following the advice on this board; I disconnected the SC board from the power board and got 7 blinks. That means the P, SS, and A boards are good and that the SC, SD, and SU boards are suspect. The power pins on SC are shorted, so that is definitely bad. I disconnected SD and SU to check if they are shorted by checking SD42 (pins 1, 2 & 6 to gnd) and SU41 (pins 2, 6 & 8 to gnd). I have a cheap multimeter which maxes out at 2M ohms, and all six pins are over range. Does that mean SD and SU are probably good?

I guess my next step is to get shopjimmys repair kit and see what happens. My backup plan is to have moduslink repair it if I can't. Do I have it pretty much right?

Thanks,
Steve

sounds like you've done your homework. other thing you try in continuity / diodetest on the buffers and run the probe slowly along the contacts at the panel ribbon connectors with respect to Vf gnd which is the plates that the bolts go in on the SD/SU. I would go slow if it's a cheap meter as response will be slow and watch for short cct.

Also we've been reading more and more about suspect loose screws and poor earthing of the boards which can cause these to pop, new screw set may also be worth while about $5 I think at SJ.

What sort of soldering gear do you have (wattage etc)

[srs]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I'll try checking the buffers. There is definitely evidence of arcing on the bottom of SC at the grounding points and several screws were noticeably loose and required more than a 1/4 turn to snug them up. The screw set seems like cheap insurance.

At home I only have a 25 watt pencil iron, but have access to a solder repair station at the local maker space.

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I'll try checking the buffers. There is definitely evidence of arcing on the bottom of SC at the grounding points and several screws were noticeably loose and required more than a 1/4 turn to snug them up. The screw set seems like cheap insurance.

At home I only have a 25 watt pencil iron, but have access to a solder repair station at the local maker space.

Yeah I think the workstation might be the go. 25w may be a bit light and a nice solid heavy tip will help get the heat into the tabs on those large smd transistors and diodes. I usually tin them with fresh solder and then heat the tab until I see the edges bubble and off. Obviously carefully snip the legs close to the body or heat the pads and gently lift them clear first.
I have a simple 40w but I have a cooper core tip, chisel style and It goes ok but I think the copper lands on yours are fairly large,

Get some flux or flux pen., makes the world of difference with soldering.

So with these screws, are they too long or missing spring washers or what do you think? It's quite incredible panasonic could end up with such a simple but wide spread problem.

I'm yet to touch one of these series although I may have a chance at a 50U30 so will be similar I expect,

[srs]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Yeah I think the workstation might be the go. 25w may be a bit light and a nice solid heavy tip will help get the heat into the tabs on those large smd transistors and diodes. I usually tin them with fresh solder and then heat the tab until I see the edges bubble and off. Obviously carefully snip the legs close to the body or heat the pads and gently lift them clear first.
I have a simple 40w but I have a cooper core tip, chisel style and It goes ok but I think the copper lands on yours are fairly large,

Get some flux or flux pen., makes the world of difference with soldering.

So with these screws, are they too long or missing spring washers or what do you think? It's quite incredible panasonic could end up with such a simple but wide spread problem.

I'm yet to touch one of these series although I may have a chance at a 50U30 so will be similar I expect,

I double checked the iron I have at home. It is only a 15 watt, definitely too small. I'll be borrowing the bigger station. I already had flux, solder braid, etc. I do not have lead free solder, I notice that this board was made with lead free, will that be a problem? I do know that the lead free requires more heat. Should I get some lead free to match what is already on the board?

The screws that were loose have no lock washer or separate flat washer. They have a wide flat head that looks like a flat washer, but is part of the head. I suspect those would have been fine had they been properly torqued on installation. My guess is that Panasonic may have switched screw types and not changed the torque specs to match. At any rate, I have ordered a screw set from ShopJimmy along with the SC board repair kit.

I have verified that there are no shorts between Vf gnd and the panel connector pins on SD or SU, so I'm happy about that.

My next step is to start lifting pins on the transistors for SC and isolate the bad parts for replacement while I wait on the repair kit. Any guesses on which ones will be bad?

Thanks again for all of your help,
Steve

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I double checked the iron I have at home. It is only a 15 watt, definitely too small. I'll be borrowing the bigger station. I already had flux, solder braid, etc. I do not have lead free solder, I notice that this board was made with lead free, will that be a problem? I do know that the lead free requires more heat. Should I get some lead free to match what is already on the board?

The screws that were loose have no lock washer or separate flat washer. They have a wide flat head that looks like a flat washer, but is part of the head. I suspect those would have been fine had they been properly torqued on installation. My guess is that Panasonic may have switched screw types and not changed the torque specs to match. At any rate, I have ordered a screw set from ShopJimmy along with the SC board repair kit.

I have verified that there are no shorts between Vf gnd and the panel connector pins on SD or SU, so I'm happy about that.

My next step is to start lifting pins on the transistors for SC and isolate the bad parts for replacement while I wait on the repair kit. Any guesses on which ones will be bad?

Thanks again for all of your help,
Steve

Geez, no spring or flat washer, No wonder. By rights it should be a recall or class action, pretty crap. speculation but Possibly stuffed up selected the wrong spec and the parts were loaded into production or they were desparate to cut unit costs. either way avoidable and preventable error.

use leaded solder

[srs]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I got the repair kit and screws from ShopJimmy today. I replaced Q402, Q403, Q422, Q423 as well as D401 and D421. They included resistors for R402, R403, R422, R423 but I did not change them out. I replaced the crappy screws with new ones that have a flat washer and a lock washer on SC, SD, SU, SS, and P, there were only enough screws to replace one each on C1, C2, C3.

The short test passes now on SC! The TV powers up with no blink codes. So that part is good.

I have a different issue now. On the bottom half of the screen only, there are some horizontal lines that go across the entire screen. Is it possible that one of the cables to SD is not seated correctly? I think that is what I will check next. The top half of the screen is good.

Thanks very much for the assistance so far!

-Steve

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I got the repair kit and screws from ShopJimmy today. I replaced Q402, Q403, Q422, Q423 as well as D401 and D421. They included resistors for R402, R403, R422, R423 but I did not change them out. I replaced the crappy screws with new ones that have a flat washer and a lock washer on SC, SD, SU, SS, and P, there were only enough screws to replace one each on C1, C2, C3.

The short test passes now on SC! The TV powers up with no blink codes. So that part is good.

I have a different issue now. On the bottom half of the screen only, there are some horizontal lines that go across the entire screen. Is it possible that one of the cables to SD is not seated correctly? I think that is what I will check next. The top half of the screen is good.

Thanks very much for the assistance so far!

-Steve

yes, that is exactly what you have. Turn off and reseat the ribbons that align with the lines. they need to go in straight and all the way, initial resistance when inserting and then they go in a fraction more.

very encouraging news for me, the reapir was those parts, having a go at a P50U30A and prordered parts before I've seen it.

Do you have pictures of the original and replacement screws?

Did you take a picture of the repaired board? Obviously the soldering station did the job.

[tom66]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Remember tw you might have to replace small SMD gate driver too, for ERC side, as that can sometimes go bad.

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Remember tw you might have to replace small SMD gate driver too, for ERC side, as that can sometimes go bad.

cheers, yeah I hope not, did cross my mind, can't get the bits in time, only in location there for 3 weeks and XMAS kills postal services. Where did you get the driver from China or local?

[tom66]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Local supplier had it. Not too expensive.

On the U30s, I'm told 1/5 of them have the bad driver IC and transistor. I had a bad transistor pair (short between Vcc & out), think the IC was ok, but not certain.

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Local supplier had it. Not too expensive.

On the U30s, I'm told 1/5 of them have the bad driver IC and transistor. I had a bad transistor pair (short between Vcc & out), think the IC was ok, but not certain.

Hmm, ok, hope I am in the 4/5. local services here not so good, but have a contact, may enquire. Very few if any shops here component reapir

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Local supplier had it. Not too expensive.

On the U30s, I'm told 1/5 of them have the bad driver IC and transistor. I had a bad transistor pair (short between Vcc & out), think the IC was ok, but not certain.

was it a C0ZBZ0001822, BD8693FVM-HVTR?

IC16502? feeds a DG302 IGBT Q16441?

[tom66]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

IC16502 drives a Q16xxx device, SOT23-5 transistor, dual. If that fails, I'd replace gate driver too, no idea if it's good.

With scope, I could see the gate drive was no good. Also Vcc (when powered up, IGBT removed) was low.

This set use separate buffers? If so do check Q16660 as if it fails short it can fry buffers by reverse bias. Rare failure but alwyas worth checking.

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

IC16502 drives a Q16xxx device, SOT23-5 transistor, dual. If that fails, I'd replace gate driver too, no idea if it's good.

With scope, I could see the gate drive was no good. Also Vcc (when powered up, IGBT removed) was low.

This set use separate buffers? If so do check Q16660 as if it fails short it can fry buffers by reverse bias. Rare failure but alwyas worth checking.

Thanks, I'll be going over the whole thing, hopefully I'm one of the lucky ones. even have spare screws from my model so i'll take them as well in case it has this earthing issue.

[srs]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

yes, that is exactly what you have. Turn off and re-seat the ribbons that align with the lines. they need to go in straight and all the way, initial resistance when inserting and then they go in a fraction more.

very encouraging news for me, the repair was those parts, having a go at a P50U30A and ordered parts before I've seen it.

Do you have pictures of the original and replacement screws?

Did you take a picture of the repaired board? Obviously the soldering station did the job.

Re-seating the ribbon cables did the trick. I ended up ordering a cheap 40w iron from Amazon and using that, it was about US$15.

Thanks for all of the help! All I need now is a stand for it.

Here are the pics you requested:

[tw2005]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Reseating the ribbon cables did the trick. I ended up ordering a cheap 40w iron from Amazon and using that, it was about US$15.

Thanks for all of the help!

Here are the pics you requested:

Thanks, nice looking job,

[busted&disgusted]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

I guess I'm starting up an inactive thread again but I have the identical problem on my TCP50ST30 also had the dreaded 14 blink code and after watching a few YouTubes I narrowed it down to my SC board by pulling the power connectors for shorts and the SC ended up showing a total short. Also as per another video showing how to test the buffer boards I tested them as well removing all of the copper colored ribbon connectors to the screen and using an ohm meter for that test as well also indicating no shorted buffer boards. I discovered a repair tech in the nearby city and he replaced the shorted MOSFETs that others have mentioned and is now installed. Everything is working great but I now have two large black lines running left to right and above both of them are fine black lines and near the bottom I have another pair of groups of these fine black lines as well. As instructed by the buffer test video I made absolutely sure no copper was exposed or showing on these copper colored ribbons after they were inserted back into the ribbon connector after the hasp or latch was pressed down. Even though this Panasonic TCP50ST30 is very clean inside is this an indication of improperly seated ribbon cables or did the 4 shorted transistors damage my buffer boards? Also another assumption I have is perhaps tiny pieces of dust or lint entered the ribbon cable connectors?? I have the back of the set back on but I guess I will have to remove it for another attempt at repair. Any suggestions are greatly appreciated.

[busted&disgusted]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

These are pictures of what is going on at the present time.

[tvtimmy]

Re: Panasonic TC-P50S30 14 blinks - 7 blinks

Sometimes it takes me 5 or 20 times to get those M. F. ers set correctly!
Make sure to power down the set before doing anything. I turn on the scrooling white bar screen cleaner to check for any lines. Keep trying, you'll get it.