Panasonic 50VT30 , Blinking 7 times.

[Moreno83]

Hey guys ,

Going to pick this 50VT30 up tonight and see if i can fix it. I still have my VT50 so this one is for sale.

Set is blinking 7 times which means the SC/SS boards. I want to do the repair myself so im searching for a reliable repair set.

Can someone recommend me a good repair set for this tv? I heard that some repair sets are cheap chinese brands so i want to avoid those.

Can i be lucky that i only need to tighten the screws?

Thanks.



ps , will post pictures when i got the tv!

[Alastair E]

Re: Panasonic 50VT30 , Blinking 7 times.

7-Blink implies SC Floating-Supply issue, which could be caused by buffer-chip.

It could also mean the SC has many short parts.

Ive not seen any kits for repairs that I would consider Complete,--whether 'Cheap-Chinese' or otherwise.

Ive done a couple of SC/SN boards, but made up my own repair-kit of parts, some sourced from China some from RS and others from Farnell...

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

Hey guys ,

Going to pick this 50VT30 up tonight and see if i can fix it. I still have my VT50 so this one is for sale.

Set is blinking 7 times which means the SC/SS boards. I want to do the repair myself so im searching for a reliable repair set.

Can someone recommend me a good repair set for this tv? I heard that some repair sets are cheap chinese brands so i want to avoid those.

Can i be lucky that i only need to tighten the screws?

Thanks.



ps , will post pictures when i got the tv!

7 is SC,SD,SU

Don't expect a turn of a screwdriver will fix it but be prepared it can be SD/SU.

Just had 2 U30 with shorted Su, good SC and I found them scarce and expensive.

probably 50/50. You'll know pretty quick though if none of the 30F131 or RJP30H2 are shorted or simply isolate the buffers as you would on any later Panny and jumper SC50.

Expecting it'll be a 5335 board, sometimes you get away with 6 IGBTs. I got 2 of these boards in limbo ATM.

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Thanks for the replies! Im going to repair the board and just order all parts that i need. Not just for this tv but also for backup for my VT50.

Im working atm , i will isolate the buffer boards and see if the tv will turn on , if not then i know what to do.

I read that its hard to repair these SC boards? Or does this count for older SC boards?

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Isolated the buffer boards and used the SC50 jumper. Still 7 blinks. Removed the SC20 cable and i get 8 blinks.

Checked the bufferboards for shorts but they are ok! Lucky me.

So my SC board , TNPA5335 , has a short somewhere. Need to wait for the parts to come in...
.

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Btw , screws on the SC board were loose! Buying a new board in the netherlands will cost me 200 euro haha. I'll wait a week or 2 and repair it myself

[freakaftr8]

Re: Panasonic 50VT30 , Blinking 7 times.

You most likely have shorted MOSFET on the SC board. Usually one or more. Also you may or may not have a blown buffer IC. If you do its most likely the SU board the very top IC shorts. This in turn takes out the SC board.

Most likely this is caused by excessive heat inside the unit always goes to the top and the top IC runs hotter than the rest.

However as you're waiting if its just loose screws its most likely just the SC board shorted. One quick and dirty way to tell if the SU in SD boards are bad not is to Pull up on the cable clamps slightly that connect the buffer boards to the panel and with an ohmmeter take the black lead and put it on the screw that connects the SC board to the SU and SD boards.. The red lead run it across the pins of each cable and if you get a beep that's your shorted Ic. If you get no beeps across all the output cables then the SC and SD boards are most likely ok

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Thanks for the reply. Yes , after some reading on the forum im pretty sure the mosfets are blown. Im going to replace them all. If 1 goes , the other 1 might follow.....

Buffer boards are fine. I tested them for short. ( ground to all pins )

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Bought a repair set from a UK seller. Replaced all IGBT's that came with the repair set and i tested it with SC50 jumper. Tv went out with a bang. I think D401 gave a bang and flash.....

Not sure if its my soldering that caused this!

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

Bought a repair set from a UK seller. Replaced all IGBT's that came with the repair set and i tested it with SC50 jumper. Tv went out with a bang. I think D401 gave a bang and flash.....

Not sure if its my soldering that caused this!

I must be lucky then. Just did two 5335 boards today, rather boring affair, no smoke no noise just a good picture.

Was it 1 you replaced? So far I've gotten away with no diodes replaced on 3 5335 boards and a 5351

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

I replaced all the IGBT's that came with the repair set.

6x 30F131
1x DAF30A
1x RJP63GA
RF1501

That is what i replaced

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

How do you replace these IGBT's? Do you use a heatgun?

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

How do you replace these IGBT's? Do you use a heatgun?

I recently got a cheap Hot Air station. To be honest, either desolder and lift the legs or cut the legs, get a 40W iron with a medium chiesel, flow solder on the metal tab and just let the heat soak in and pretty soon it will bubble and just come off.

I tried the hot air on its own but too slow but the hot air and the soldering iron is quicker again especially once there is a bit of heat in the board given that the board is the heatsink.

Maybe buy in bulk if you're doing a few of these. I got 12 each of the 30f131, RJP30H2 just in case , I'm currently touching wood but the TV is still going but there's a fair amount of heat in these boards, really could do with better heatsinking, but hey, it's more important to have a really thin TV than to have bulky heatsinks

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

Oh, replace is the same, flux, tin and heat the tab, flows and sets. Normal 40w iron and a copper alloy tip. The tip really transformed this very cheap iron

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

I replaced all the IGBT's that came with the repair set.

6x 30F131
1x DAF30A
1x RJP63GA
RF1501

That is what i replaced

So here's a question. Did you go over the board completely and what IGBTs were short in the beginning?

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

Removing them is easy , i had no trouble with that. Im having trouble soldering the new ones. Do you also use a heatgun for that?

Yes i ordered a repair set and a bulk. Could you please tell me how to measure the new IGBT's so i cant go wrong? I can look on youtube but you have repaired so many boards and you know what your doing. This is my very first SC board repair.

[Moreno83]

Re: Panasonic 50VT30 , Blinking 7 times.

So here's a question. Did you go over the board completely and what IGBTs were short in the beginning?

No , i ordered a repair set and replaced those. Should have done that i guess....

[vinceroger69]

Re: Panasonic 50VT30 , Blinking 7 times.

Oh, replace is the same, flux, tin and heat the tab, flows and sets. Normal 40w iron and a copper alloy tip. The tip really transformed this very cheap iron

have you got a link to the copper alloy tip i may try one in my spare backup iron thanks

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

I see. seems strange you have trouble in the reverse. If you can get enough heat to get it off then the reverse should be the same.

So today was the first time I tried the hot air otherwise i would have done it without.

I blew the hot air onto the legs and at the same time having tinned the back of the transistor, placed flux on the board and then tinned the iron tip flowing solder so it touches the board and the metal tab.

When it reached temp the solder actually wicked under the transistor. If you're having trouble try tinning the tab on top and glide the iron tip back and forth to distribute the heat.

practice will improve things, I'm just getting the knack myself.

As far as knowing what I'm doing, probably 50% true, 50% luck and take a gamble from time to time.

What I'm interested in is what was short in the beginning?

Why? Because the kit contents is somewhat interesting due to no RJP30H2 IGBTs.

Were there instructions or location numbers given?

If I look at the 3 boards I've faced. Two have simply had 3 x 30f131 and 3 x RJP30H2.

the board that had the blown RJP63G4 had 3 x 30F131 shorted which I believe failed first taking out Q661. They're not the same bank of 3 30F131 that go when the RJP30H2 are shorted.

So if you simply located all the 30F131 replacing 6 but did not check the RJP30H2 then this maybe what went wrong? We all have a blowout but always nice to go back over and analyse it to learn.

So my curiosity is, did you just get the kit and throw it in or how did you determine it was the right kit?

Any chance the RJP30H2 IGBTs were overlooked?

IGBTs normally just go dead short on failure so finding them is usually pretty easy .

I do have a 5335 spare out of the TV if you have some points you'd like to compare.

[tw2005]

Re: Panasonic 50VT30 , Blinking 7 times.

have you got a link to the copper alloy tip i may try one in my spare backup iron thanks

I was hoping that question was not asked, It was from a collection spare tips for an old pace soldering station.

I actually don't know the true composition but they do conduct very well and the plating is good quality as I get very little corrosion of the tip, just a quick sponge. Pretty sure it's some type of copper alloy or plated copper.

this link is the style of tips I've got, not a perfect fit but good enough. They are PACE.

http://www.newark.com/pace/6993-0210...ces/dp/71C6552