Panasonic TNPA5335 from 50VT30/50GT30 sos6

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I will put it back in tomorrow and try it again but im fairly sure it didnt light up at all

Lets call it a night and get some sleep, appreciate all your help Thank you

Ditto

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I'm thinking compare the components around this LED to the good board, looking for shorts,open cct or bad resistance.

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I will put it back in tomorrow and try it again but im fairly sure it didnt light up at all

Lets call it a night and get some sleep, appreciate all your help Thank you

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I have to think. What has me curious is the fact the the LED never lights up at all on startup. there's another diode if that went open that could stop that lighting up.

I'm fixated on this because one of my replacement boards which had 6 blink was a replacement and that LED was blown so triggered the SOS6, it never lit but unless there was a dead short on SC2, you should see it light even for a moment, maybe not full brightness. You said nothing there at all.

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

That seems to be ok also about the same on both board and no open cct or short

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Ok, well I was hoping for some clues about the bad set especially if the bad set came with the bad SC.

So we have not found anything drastically different yet then. On the SC board, there is a 5V reg near Sc46, can you measure resistance centre pin - 1, centre - 3, pin 1 - 3

I'm rapidly running out of ideas, too.

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

ok, i have a working set of buffers i have 2 of these TV's one has good buffers one doesnt

I am negotiating with the seller to get a set of buffers

Back to the testing>
I get both board to light the LED up
bad board across led 1.812 and good one 1.814
C561 bad board .946 and good board .921

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Yep thats where i am testing it

Obviously I'm not reading the tracks right. So 200K difference, maybe try that again in diode mode and see how close they are.

with that onboard green LED, retry that in diode mode and try both polarities, compare both boards.

Also sometimes you can see the faintest of green glow in that LED in diode mode, watch for that too.

With the bad buffer, which board and how did you determine it was bad?

What pins are shorted?

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Yep thats where i am testing it

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I missed the decimal point sorry
17.05 and 17.08

Faulty one C561 left side to gnd .516 M ohms , right side to gnd 0 ohms

working one C561 left side to gnd 308 K ohms , right side to ground .2 ohms

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Is this where you are testing P5V. can't be zero ohms, left side is gnd, right should be 5V line

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Ok, C561 has me puzzled, maybe my direction is wrong. Find an earth point and then re do the resistance on both sides. can't be 0 as that would short and no point having a cap across the same level.

Try continuity across that as a second test.

So to be clear, TP82 on good 17.05K, TP82 on bad 1708K? Or did you miss the decimal point

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

ok ,sorry it was mega ohms

I just checked sc2 on the working board 11.65 m ohms and rising

C561 on both boards 0 ohms
TP82 to ground 17.05 K ohm on good one
TP82 1708 K ohms on bead board

The dead board has 7 flashes connected and 6 flashed isolated and jumped

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

seriously 11.42 ohms, not k or megohms? with it that low surpised it did not give a different blink code or locked solid LED on the front. effectively short so there has to be a shorted IGBT on the board somewhere.

The manuals are no good 2011 on , virtually impossible to read the diagrams.

P5V measure across C561, i think it's a smd ceramic, right side of SC20 connector

P15V measure gnd-TP82, could be near Sc20

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

SC2 11.41 ohms
LED not open cct

Not sure where P5V and P15v are though sorry

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Always risky unless from someone who deals in bulk like SJ or PAYLESS components who can ship a board for $16! I did the same from a VT20, buffer shot, SC ok, cracked screen jobby.

Depends how they worded it but I lodged paypal disputes and got refund, no return. I did have correspondence asking them to check befor shipping particular checkpoints which both were shorted DOA.

So this does suck. Can you measure the resistance on SC2, P5V and P15v lines on the SC isolated. Also, check that green LED and see if it's open cct.

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

A full set of boards turned out to also be one buffer short

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

I got it from USA, problem is i got a full set of boards for $220 delivered and to send them back its going to cost $80 and i will lose the $40 it cost to send them here because the seller doesnt get the shipping cost with the new global shipping program ebay has

No, no green led at all

[tw2005]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Oh, so you're saying you fixed yours and got it going but this one is throwing a 6 blink but was supposedly good? Local purchase or O/S? Refund time if it was PAYPAL. I had 2 bad for my V20 got 100% refund.

So does the tiny green LED light up on the SC board at all?

[nick1969]

Re: Panasonic TNPA5335 from 50VT30/50GT30 sos6

Hi TW2005,

definitely none shorted, i bought this board on ebay it was suppose to be from a new tv with smashed screen. The SC board from my TV had 6 or 7 shorted that i managed to get working