Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting TVs and Video Sources
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 10-21-2020, 07:58 AM   #1
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Question Panasonic Viera TX-P42S21B - 7 Red Flashes

My Panasonic Viera TX-P42S21B 42" 1080p HD Plasma developed a fault a few days ago.

It looks like it's going to come on, makes that click sound but then goes off. Doesn't turn on via remote.

So, obviously it's likely one or more of the components/boards. I don’t see any results for my model or a service manual anywhere, but I’ve briefly looked into it with similar models and apparently it is the SC and or SM board(s.)

How accurate are the fault blink codes? I don’t see any glaringly obvious damage on the SC/SM boards but the power supply has some markings. See images. Could the PSU be the original issue, causing this instantly happen again if I replace the SC/SM? Or am I correct in saying when an SC/SM goes bad it can take out the PSU too? How do I correctly diagnose everything?

I briefly spoke to a couple of part sellers, since they advise asking questions before buying.

Answers:

I asked the same slimmed-down question as this thread to two sellers. The first on a listed power supply and the second on a listed Y-SUS.

A) Hi, I have been advised that is a Y sus issue i am afraid. Many thanks, […]

A) […]Hi, yes this board will do but the fault can also indicate a problem with the X-SUS board and or the Buffer board too.Thanks[…]

They never brought up the marking on the PSU.


I don’t have a multimeter to hand and I’m a novice anyway. But I have ordered one for Sat. I will be looking more into it over the week until it arrives but any info/help would be greatly appreciated.

Video of fault:

https://youtu.be/cSnk7HWk38E








Last edited by Paft; 10-21-2020 at 08:43 AM..
Paft is offline   Reply With Quote
Old 10-21-2020, 08:33 AM   #2
dick_barton
Badcaps Veteran
 
dick_barton's Avatar
 
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 5,712
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

T200 looks as though it has soot around it. What is the underside of it like. (underside of the board).
There's not alot you can do without a meter available.
Use your new meter when it arrives set to diode mode to check D207
__________________
Willing to help but I'm no expert.

Last edited by dick_barton; 10-21-2020 at 08:38 AM..
dick_barton is offline   Reply With Quote
Old 10-22-2020, 10:13 AM   #3
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

First thing to check is a short on the sc board connector going to the power supply. Unplug it and check it in continuity mode(beeping meter sound). If you find one or some, remove the 4 screws that attach the SM board to the SC and check again. A beep that lasts longer 5han 6 seconds means a short. Reversing the leads will give a beep of about 3 seconds, that's just from the capacitors charging up. If no beep, check the SM board for shorts. Place one lead on one of the 4 ground holes (marked in red) and rake the other lead across each ribbon connector.
Attached Images
File Type: jpg sketch-1603382545813.jpg (115.1 KB, 14 views)
tvtimmy is offline   Reply With Quote
Old 10-23-2020, 11:20 AM   #4
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Thanks for the replies.

-How do I correctly test the SC board?

-I get a continuous beep on the SM board on several of the SM6 ribbon pins. They look like they go to the fourth IC(?) chip from the left.

-I get a continuous beep on D207 on the power supply where the black marks are. I don't see anything obvious underneath. (But it's rather grey in England and getting dark. I had to use flash. I'll take some again tomorrow)

Attached are images of the bottom of the PSU and the SM or: https://imgur.com/a/vI5Geh9
Attached Images
File Type: jpg IMG_20201023_174751.jpg (1.07 MB, 4 views)
File Type: jpg IMG_20201023_174945.jpg (843.0 KB, 1 views)
File Type: jpg IMG_20201023_174952.jpg (960.3 KB, 1 views)
File Type: jpg IMG_20201023_174959.jpg (1,007.1 KB, 1 views)
File Type: jpg IMG_20201023_175006.jpg (946.1 KB, 3 views)
File Type: jpg IMG_20201023_172024.jpg (693.9 KB, 13 views)
Paft is offline   Reply With Quote
Old 10-23-2020, 12:04 PM   #5
dick_barton
Badcaps Veteran
 
dick_barton's Avatar
 
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 5,712
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

D207 looks as tough it could be across a transformer winding so would need to be checked by lifting one end of the diode from the board.
dick_barton is offline   Reply With Quote
Old 10-23-2020, 02:55 PM   #6
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Your SM board is bad. Take out the 3 screws that hold it in and unlatch the 3 connectors going to the SC board Flip it over, with the ribbon connectors still attached to the panel, over to the outside of the tv. On the SC board you have to short the 2 pins of SC50. I use a thick paperclip. Turn on the tv and check if the green led on the SC is lit. Don't run the tv for more than 20 seconds! Green led means the SC is good. Do this test before messing with the power supply diode.
Attached Images
File Type: jpg sketch-1603485793218.jpg (55.4 KB, 10 views)
File Type: jpg sketch-1603486664283.jpg (85.5 KB, 9 views)

Last edited by tvtimmy; 10-23-2020 at 02:59 PM..
tvtimmy is offline   Reply With Quote
Old 10-24-2020, 08:21 AM   #7
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Thanks for the replies again.

Following you, steps, tvtimmy-- I turned it on for around 3 sec. I get a green light on the SC board.

Does every board have a green LED? Where do I go from here? Do as dick_barton suggested?

Last edited by Paft; 10-24-2020 at 08:27 AM..
Paft is offline   Reply With Quote
Old 10-24-2020, 09:44 AM   #8
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Now you have to buy a SC. Board. I would replace the mounting screws for it and the SC mounting screws with the new ones with the lockwashers.
tvtimmy is offline   Reply With Quote
Old 10-24-2020, 10:47 AM   #9
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

I know it's very difficult on your end to diagnose things you're not even in front of.

"Now you have to buy a SC. Board." Did you mean SM board? The one that the ribbons connect to?

Is this a bit of a guessing game now or do you think the new SM board will solve it? The SM board is a good price but the other bits start adding up.

Why do the screws need replacing? How do I know exactly what to get? I don't have a calipar.

Last edited by Paft; 10-24-2020 at 10:50 AM..
Paft is offline   Reply With Quote
Old 10-24-2020, 12:53 PM   #10
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Oops! I meant SM board. Your SC is ok.
Shopjimmy.com sells them. The old ones don't have lock washers and they loosen up over time.
That's what caused your tv to go out.

Last edited by tvtimmy; 10-24-2020 at 12:55 PM..
tvtimmy is offline   Reply With Quote
Old 10-24-2020, 01:09 PM   #11
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Cheers. I assumed that and I ordered one for 16.99. Estimated delivery Thu, 29 Oct.

Fingers crossed. I'll update once arrived/fitted.

Board failure from the screws? That's ridiculous. Edit: Just an FYI all the screws I've removed have been have had lock washers as fair as I can tell.
Attached Images
File Type: jpg IMG_20201024_202142.jpg (275.8 KB, 5 views)

Last edited by Paft; 10-24-2020 at 01:26 PM..
Paft is offline   Reply With Quote
Old 10-24-2020, 01:27 PM   #12
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

When you fit the ribbons and turn on the tv, you will probably see lines going across the screen. Turn off the tv before you readjust them. Take your time, It still takes me 5 to 25 times before I get them all perfect.
tvtimmy is offline   Reply With Quote
Old 10-28-2020, 01:47 PM   #13
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Well, it was definitely the SM board.

Sadly part of the right side of the screen is blank/missing.

I will point out that the part I got was "identical" part number wise but it was from a TX-P42S20BA instead of TX-P42S21B. I chanced it thinking a part is a part. Is that the problem? If that's the case I guess I am one of those annoying customers on eBay. I'll keep it and sell it dearer.

Edit: I've ordered Panasonic 42" TX-P42S21B TNPA5086 AC 1 SM Buffer Board Free Tracked P&P
Attached Images
File Type: jpg IMG_20201028_193710.jpg (554.1 KB, 27 views)

Last edited by Paft; 10-28-2020 at 02:35 PM..
Paft is offline   Reply With Quote
Old 10-29-2020, 07:19 AM   #14
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Appologies if double posting isn't allowed but editing has a time limit.

Attached are images.

I noticed they do differ slightly-- extra or missing components. I assume I've answered my own question?

Am I alone in thinking it's an odd way to work? Same part numbers but they're not...
Attached Images
File Type: jpg IMG_20201029_125309.jpg (604.6 KB, 5 views)
File Type: jpg IMG_20201029_125322.jpg (352.2 KB, 7 views)
File Type: jpg IMG_20201029_130755.jpg (400.5 KB, 12 views)
Paft is offline   Reply With Quote
Old 10-29-2020, 01:38 PM   #15
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

That board controls horizontal lines across the screen. Check the ribbon latch on the bottom buffer board directly under the SM board. Those bottom buffers control vertical lines of the screen.
tvtimmy is offline   Reply With Quote
Old 10-29-2020, 01:42 PM   #16
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Check this ribbon latch.
Attached Images
File Type: jpg sketch-1604000403379.jpg (97.8 KB, 12 views)
tvtimmy is offline   Reply With Quote
Old 10-29-2020, 02:39 PM   #17
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Thanks. I already cancelled that order, after finding a 6.38 SM board. That hasn't been dispatched yet. Should I cancel it?

Is there a specific method to test the bottom buffer boards? I assume that's a faulty bottom buffer too?

I reseated the ribbon you mentioned twice. Although that's the first time I've touched it. No change.
Attached Images
File Type: jpg IMG_20201029_205731.jpg (556.6 KB, 8 views)
File Type: jpg IMG_20201029_205658.jpg (685.2 KB, 7 views)

Last edited by Paft; 10-29-2020 at 03:09 PM..
Paft is offline   Reply With Quote
Old 10-29-2020, 03:17 PM   #18
tvtimmy
Badcaps Veteran
 
tvtimmy's Avatar
 
Join Date: Mar 2015
City & State: milwaukee,wi
My Country: usa
Line Voltage: 120VAC/60HZ
I'm a: Knowledge Seeker
Posts: 990
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

I don't know a way to test them. Are you missing the last part of the display on all inputs?
There is a way to reverse the image on the screen to see if the mainboard is a problem, but I can't remember how.
tvtimmy is offline   Reply With Quote
Old 10-29-2020, 03:22 PM   #19
Biruslapio
Senior Member
 
Join Date: Nov 2013
City & State: SC
My Country: Brasil
Line Voltage: 220V 60Hz
I'm a: Student Tech
Posts: 164
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

The ribbon cable that goes from the mainboard to C-Board left side(facing the TV backwards), try reseating that one.
Biruslapio is offline   Reply With Quote
Old 10-29-2020, 03:23 PM   #20
Paft
Member
 
Join Date: Mar 2020
City & State: No
My Country: UK
Line Voltage: N00b
I'm a: Knowledge Seeker
Posts: 20
Default Re: Panasonic Viera TX-P42S21B - 7 Red Flashes

Well, I call tell without anything actually connected because the AV source option box is cut off for example. As are any other screen or menu that takes up that area. I'll test all inputs for the hell of it though.

Thanks for your help so far.

edit: Didn't see you post Biruslapio--looking now. I will point out that nothing has been touched before besides the power supply and buffer board(s.)

Last edited by Paft; 10-29-2020 at 04:24 PM..
Paft is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2020
Powered by vBulletin ®
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 05:09 AM.
Did you find this forum helpful?