Panasonic sc tnpa5081 rebuild

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Anyone with a 42" model TNPA5081 able to check Q16660(Q660) and tell me what markings are on the device? REV AH , 42". rev AG 46"

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Woo Hoo! Just fixed my first TNPA5081

I had a few snags. first attempt failed as I did not detect 2 shorted smd transistors which fed the inverter chip. Result of that was flash of light, and pop. The only casualties were the inverter chip I replaced and the 3.9k 1/8w resistor.

2nd problem is these Toshiba IGBTs which have 2 variations and I'm getting no feedback from the post.

I'm in 2 minds, sub the replacements in the board and see if it works or leave it alone given the amount of hours I've put in.

This is the list of parts replaced.

IC16501 M81737FP FET driver
IC16521 M81737FP (only one failed but replaced both)

Q16402 DG502LW shorted
Q16403 DG502LW shorted

Q16421 DG402RP shorted
Q16422 DG402RP shorted

Q16661 RJP63F3A shorted

IC16773 TC7SH14F, Toshiba , Schmitt inverter ,marking HA
Q16701 MMBTA92 NXP (7E W) shorted
Q16702 2PD601ART NXP (C3 W) shorted , these I cannibalised from the first board as they cost stuff all but have to order large quantities and I was so close to fixing it I could'nt wait to get one going.

Q16021 30F125 ®
Q16022 30F125 ® only one had shorted on each board. Have not located this version transistor so one board has become a donor for these

Q16441 Q16452 45G128 ® & 45G128 ended up fine.

On the first board, IC16724 5V 78M05 is shorted, the 5V line on the matching buffers was also short.

Not on this fixed board it was fine, so to the other is fine.

I hope someone out there can help me out with the IGBTs.

Even if somone can get them B1JADN000008 from Panasonic parts stockists cheap and ship to me

[tom66]

Re: Panasonic sc tnpa5081 rebuild

Wow! Awesome! I've gotta keep an eye out for these -- lots of parts to fix, but looks relatively inexpensive?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Wow! Awesome! I've gotta keep an eye out for these -- lots of parts to fix, but looks relatively inexpensive?

Thanks mate. It'd be so easy to keep this to myself but if this one can be fixed it gives hope for other similar SC boards.
Since they seem to commonly fail and supplies ar drying up it's a good alternative for those who dare.

the price of the boards will only go up as supply dwindles.

Parts about $30 if you don't get them from Panasonic and don't mind trusting a chinese supplier.

The hitch is the R marked 30F125 and I've got no response to my post.

I may just try the standard 30f125 and see how it goes.

Do you have any connections with panasonic techs or suppliers?

I'm hoping at worst somone would order these and ship to me if I get stuck.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

No contacts, sorry. I know some TV tech friends, but I only ask for the occasional manual.

The device code is most likely all is necessary to match.

® may mean a specific variation or temperature range, perhaps a different factory, or a Panasonic internal code.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

No contacts, sorry. I know some TV tech friends, but I only ask for the occasional manual.

The device code is most likely all is necessary to match.

® may mean a specific variation or temperature range, perhaps a different factory, or a Panasonic internal code.

No, I believe it's electrically different. The SS board has both R and no R versions onboard. Panasonic have different part numbers listed for each.

They react differently when tested.

I'm suspecting it has an inbuilt diode and it's to help with reliabilty but it's the sort of thing an engineer would know more about.

It would not surprise me the standard version would work but at what expense for durability?

I can only guess and presume, hoping there's somone out there who has a deeper level of knowledge of IGBTs and there applications.

The schematic symbols give no clues of any difference.

On another note, I did the SC50 bypass and saw no reaction on the screen, the TV and boards just power up as normal.

I was also wrong about the board not running hot, The largest heatsink where the DG502LW IGBTs gets hot enough for it to be uncomfortable to touch too long.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Got the part number wrong 30F125 ® is B1JADN000009

Just looking at the 45G128s, they both have identical circuit setup resistors and cap so I'm thinking what i have will work. One is R, the other no R?

The only thing I can think of is the 30F125s are paired so I wonder if that has anything to do with the different versions.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

Huh. Yes, that's more than possible. I notice the non-R version usually has an external diode. I think that replacing them all with "R" versions would pose no hazard, if you could source them. Perhaps Toshiba have similar equivalent semis available?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Huh. Yes, that's more than possible. I notice the non-R version usually has an external diode. I think that replacing them all with "R" versions would pose no hazard, if you could source them. Perhaps Toshiba have similar equivalent semis available?

My problem is the reverse. I've purchased all non "R" versions, originals were "R".

Anyway, just fixed another. Have taken the risk and used non "R" 30F125 in this one and it works!!

We'll see how it goes as I'm going to leave this in the TV for research.

This one was much cheaper in parts. This is the purchased faulty board.

5V line on buffer board short.

This is the list of parts replaced.

Q16661 RJP63F3A shorted

IC16773 TC7SH14F, Toshiba , Schmitt inverter ,marking HA

Q16702 2PD601ART NXP (C3 W) shorted ,

Q16021 30F125 ®
Q16022 30F125 ® only one had shorted . Replaced both with non "R" I purchased.

IC16724 5V 78M05 is shorted, pilfered 5V reg from a dead samsung buffer board. Same package but up a level for current output.


FET driver ICs were good.

Blurry picture as I have the shakes.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

What TVs are these used in?
You tried to send me a PM but my inbox is full.... I've emptied it now so please re-try.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

If there's a spot for a diode (e.g. next to the IGBT) it would probably be good to install one. Maybe a 250V schottky, if available.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

What TVs are these used in?
You tried to send me a PM but my inbox is full.... I've emptied it now so please re-try.

It'd be hard for me to list them all, google TNPA5081 I guess. I don't have a list at hand. I'm sure if you dig through Flat TV etc you can get info there.

Oh, and if you were really stuck for a revision, not much work to convert between 42,46 &50. Larger sizes have additional transistors installed.

Revisions

none

TC-P54G20
TC-P54G25
TC-P54S2

AF
TC-P5032C
TC-P50G20
TC-P50G25
TX-P50G20B
TH-P50V20A

AG
TC=P46G25

AH
TC-P42C2
TC-P42G25
TX-P42G20B

AK
TC-P50VT20
TC-P50VT25

AL
TC-P54VT25
TC-P55ST30

AM
TC-46PGT24

AP
TC-P50GT25

AY
TX-P50VT20B

AW
TH-50PF20U
TX-P50G20B

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

If there's a spot for a diode (e.g. next to the IGBT) it would probably be good to install one. Maybe a 250V schottky, if available.

There's 2 , Rohm RF2001 TM3SW Fast Recovery Diodes as part of the setup so maybe I have nothing to fear?

I just had a quick look through RS and stuff me this kind of device is $20 a piece.

Dead boards are valuable for stripping then. probably why new genuine I've seen $400 price tags!

Have not found exact specs but suspect 300V 20A which makes sense since the 30F135 is a 330V 30A IGBT.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

Interesting... You can most likely use any 250V (>Vsus) or higher fast recovery diode. Current rating isn't that important.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Interesting... You can most likely use any 250V (>Vsus) or higher fast recovery diode. Current rating isn't that important.

No doubt you could.

Nothing's caught on fire yet. Looking good.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

The larger sizes also will use different ERC capacitors and inductors. If you can source the parts there should be no issue converting between sizes.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

The larger sizes also will use different ERC capacitors and inductors. If you can source the parts there should be no issue converting between sizes.

You're spot on, inductors and caps main difference in the samller sizes too. Been doing some research on this Tom?

I've cross referenced the parts in excel.

That's why I had an earlier post for info on a particular Transistor different in the smaller versions.

No responses, disappointing.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

The LC tank circuit that the L's and C's form is matched to be resonant with the panel's capacitance, around 50~300nF (which is huge... when you consider it's basically an air-gap capacitor.) A drop in efficiency would occur if the wrong screen size board is used. I'm not sure if this is a difference of 10W (hardly noticeable) or hundreds of watts (PSU going into protection mode on bright scenes.)

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

You amaze me sometimes!

Interesting, because the AW board has an additional small smd ceramic between the inductors and I think it's a different panel version to mine but no visible difference on my screen (AF was original board)

I've found no differences between AP & AF yet.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

My bet would be any differences could be small changes in gate resistors or other such components for better reliability or lower EMI. Ever wondered why almost every plasma display uses a metal case yet an LCD uses plastic? The reason is because the EMI produced by the sustaining process is extremely high, and the casing is just one part of the shielding to reduce it to acceptable levels.