prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

[cadillacman]

proview 48" plasma. powers on to a couple flashes of sparkles and thats it. Has audio. after a few mins it shuts down..

( was told it worked fine then shut off after some time.. suspected cold solder.. obiously got had on this one too)


for the life of me i cannot find more then one fuse in this tv. Pretty scary actually.

i found a shorted transistor on the z- sus board. its a fs9n60a the little gate resistors going to it check o.k. one leg goes to a a 314j ic.

I pulled the buffer boards and no apparent damage there.

What are the chances its just this transistor? I doubt it, but man i would really love to fix this thing its huge!

[rayrod81]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

It could be just the transistor. It looks like the z-sus actually serves the same function as most y-sus boards do and your symptoms usually indicate a bad y-sus or buffers (in this case a bad z-sus and/or buffers). It looks like someone has removed or replaced Q826 before.

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

dude i think it tried to remove itself! the metal is purple from heat!! and the solder was all burnt looking around it.

i thought the same thing but if you look they share the same date code.

Opening this up i almost cried because i could see it was what i call a "chumbawumba" set ( heh) cheapo korean made right?

well i guess ill hunt doen the transistor and give it a shot. I have no winners in this lot of tvs just a bunch of junk so far.

i highly doubt ill be able to find a good zus board for this set.

[PlainBill]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

Look at the date of manufacture - November, 2004!!!

PlainBill

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

yeah i have a couple old plasmas to look at still.. a old gateway 50 incheer(ish) and a big 55er or some sort or another

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

I am having a hell of a time finding that mosfet. Can anyone reccomend a good cross reference or is this thing pretty specific?
]

schmoozed digikey chat they game me the standard it crosses to the pb free version story and sorry we dont stock..

so i made them dig further and they came up with this:

http://search.digikey.com/scripts/Dk...0ZT4&x=16&y=14

[PlainBill]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

I am having a hell of a time finding that mosfet. Can anyone reccomend a good cross reference or is this thing pretty specific?

It's actually a IRFS9N60APBF. Bot Digikey and Mouser list them, but don't have stock. I'd contact Digikey and ask them to suggest a substitute. It's really not that exotic a part.

PlainBill

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

Ok so we found the cross for that smd transistor. I actually had one close enough to test with here so put it in..

now it powers on and shuts down afterwards unless the zsus is disconnected. Rechecked my transistor and its not shorted.. however i did miss something.

there are 8 large transistors mounted on a heat sink. 4 of the 8 tested shorted in circuit between the center and right legs. I did some testing and narrowed it down to one bad transistor.

the number on it is 5n3003.. the challenge again- nobodys got one.. UGH.. Is this par for the course on those cheap korean tvs?
so digikey pulls through again with a cross for a FDA38N30-ND
http://search.digikey.com/scripts/Dk...0-ND&x=15&y=23

has something here not quite perfect but half close..

with my test transistors it powers on and i gert flashes of it trying to make a pic.. i hope with the correct transistors i can make this thing work but who knows.

Time to put her off to the side untill i get my next parts order.

[cadillacman]

Re: provoew 48" plasma pd46ag1 flashing screen, audio ok...

My parts finally came in from digikey. Heading down to the basement now to put em in. I sure hope i can fix this thing. Ive had enough strike outs lately. I dont like it when inanimate objects beat me

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

F-me.. another dud.

after replacing those transistors, i powered her up. It came up with heavy flashing and lines scrolling from top to bottom very quickly..

after about 5 mins of checking, wiggling, rechecking the tv shut down. the whole time i was monitoring for signs of something running too hot and all seemed well except my picture issue.

It will not stay powered on with the z sustain plugged in but powers on and stays on with the zsustain power unplugged. UGH. here we go again.

rechecked my work, no shorts.. ok so we have a new issue. Theres two hybrids on the zsus, the top ones heat sink was cool to the touch, the bottom one warm. I suspect one or both of the hybrids have shat as well, but i really dont have the patience to confirm at this time. I also dont have the money to try them at this point.

i will update with any other info if i get back to it, but heres another set headed for the shelf of death.

[PlainBill]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

F-me.. another dud.

after replacing those transistors, i powered her up. It came up with heavy flashing and lines scrolling from top to bottom very quickly..

after about 5 mins of checking, wiggling, rechecking the tv shut down. the whole time i was monitoring for signs of something running too hot and all seemed well except my picture issue.

It will not stay powered on with the z sustain plugged in but powers on and stays on with the zsustain power unplugged. UGH. here we go again.

rechecked my work, no shorts.. ok so we have a new issue. Theres two hybrids on the zsus, the top ones heat sink was cool to the touch, the bottom one warm. I suspect one or both of the hybrids have shat as well, but i really dont have the patience to confirm at this time. I also dont have the money to try them at this point.

i will update with any other info if i get back to it, but heres another set headed for the shelf of death.

One rule of thumb I use is to look at the inputs. If it doesn't have at least two HDMI ports, it's at least 6 years old, and I won't touch them. It's not that I scorn component inputs (OK, I do ), it's more likely that a plasma set of that age sucks more power and is likely to have screen burn issues.

PlainBill

[cadillacman]

Re: prpvoew 48" plasma pd46ag1 flashing screen, audio ok...

yeah, i know that now lol..
i sure hope my backordered transistors get here for that old lg set im fixing, at least with that one i can sell it and be back to even on all these sets..

my bunghole hurts man