TH-P50G15A - 6 Blinks- Bad TNPA4782

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Pin 1 is NC. Well that's pretty rough. Do you have flux pen and a very fine conical tip?

We seem to be heading off in tangents now. I'm still curious about the OL across the diode

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Just tested PC601 out and changed it, doesn't seem to change my readings for D608 though. I was trying to replaced some extra parts IC464, IC465 near the M81707 FET drivers to be safe but ended up peeling these traces off... Barely even touched it with my iron and it came right off for both of them too! it doesn't seem like the trace goes anywhere, are they just place holders?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Try opto PC601, they're pretty common on sc,ss boards if you have scraps

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Even with the FET removed I'm still not getting the same readings as you. I'm thinking theres a problem somewhere in the area where D608 is. My D608 reads .707 and OL

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Actually, i was being sarcastic and now i'm not joking but I think this FET is shot. the whole casing is cracked that's why that leg crumbled out. But this board was working like this except that anomally I discussed with Tom. Which brings me back to these boards working with this part of the cct omitted.

So maybe get a FET, I am LOL.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Dang that sucks wait are you getting the same readings on the pads with the fet removed? As in post 53?

yep little or no difference. you never know but maybe my fet was open ? I actually wanted to test the FET out but that chance is gone

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

FQD4P25 may be ok not that helps me find one any easier

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Dang that sucks wait are you getting the same readings on the pads with the fet removed? As in post 53?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

well game over for my board. just destroyed the Pfet. casing cracked and leg fell out.

bugger

Not sure you're on the right track though as i get the same results with the FET out. I don't think you can get more open cct than what i got with no FET at all now!

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Any chance we can start referring to D806 as d608, i keep looking for a diode that does not exist

Ahh sorry bout that, Don't know why I keep getting them confused. Must be from a past board I worked on.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Did you remove both of those ICs to get the tv to work?

My D806 was completely blown in half so I had some suspicion the damage could go to that FET. I could be wrong though. I have seen and had some FETs that have completely blown which went open cct but the damage is usually obvious.

No, that's how that board is from manufacture which is my point. panasonic decided to delete it somewhere along the line. None of the photos at SJ show it deleted but i have one and if you go through Hombre's post he has a 46" board also with no vset cct.

I have 2 rev AF but hey are not the same. I don't have the other board in front of me just the one with the same setup as yours.

I'll remove my FEt and see what it does out

Any chance we can start referring to D806 as d608, i keep looking for a diode that does not exist

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Did you remove both of those ICs to get the tv to work?

My D806 was completely blown in half so I had some suspicion the damage could go to that FET. I could be wrong though. I have seen and had some FETs that have completely blown which went open cct but the damage is usually obvious.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

have you looked at the pictures I posted of that part of the cct being deleted? I have two AF boards , one with, one without that Vset cct, so clearly it's possible for it to be removed and the Tv to work.

I suppose I could remove mine and check that P fet. i always thought they'd blow short and FETs need to be switched on to check. I think very early on I did not know this and had a FEt show open but I was testing wrong. Don't kow much about P fets but that one is unique, I tried looking for a sub a while back for a post and never had any luck. Also unique I think for these models.

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Yep, I was also getting OL in cct. This would explain the different readings I got for D806 which is connected to the gate and source of that FET.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Looks like I found the problem, I desoldered it and I'm not getting any readings at all from it seems like it blew. It seems to be a P-Channel 250V 3A Mosfet vg = 30v. Now If I could find a suitable replacement from some of my salvaged Panasonic boards.

I isolated both R613 and R869 and they measured good.

so what are you saying , you can't replicate in cct my readings in diode mode?

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Looks like I found the problem, I desoldered it and I'm not getting any readings at all from it seems like it blew. It seems to be a P-Channel 250V 3A Mosfet vg = 30v. Now If I could find a suitable replacement from some of my salvaged Panasonic boards.

I isolated both R613 and R869 and they measured good.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

did you isolate r613 to confirm? also watch out for burn out tracks could be open ccts

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Hmm well they ohm out fine now that I replaced them. I was wondering what measurements do you get from Q604? the SMD mosfet next to D806, im having some suspicion on that one.

blk lead on D, I get is 9.36k G-S, ol on any other
red lead on D, 2.26Meg D-G, 2.31Meg D-S

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Hmm well they ohm out fine now that I replaced them. I was wondering what measurements do you get from Q604? the SMD mosfet next to D806, im having some suspicion on that one.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Well just tried replacing IC561,562, and 563 and still no avail. What measurement did you get on diode mode for D608?

answered in post #40 but now with this huge 1watt zener 0.663 & 1.7.