Pana TCP42C2 8 blinks SS Board components

[steves7839]

Hi all!
I have the titled set that works for hours, ran most of the Superbowl, then shut down with an 8 blink SOS. Unplugged, it powers back up almost immediately and continues to work.

I can force shutdown by heating the SS board in the area of Q101 and Q102 and D316. D316 reads open in both directions in diode check and infinite Megohms resistance. It is a surface mount with legend 8303 stamp. Questionable solder connection. Can you ID this component? Searching the manuals I have not yet found it in manuals downloaded from BC links.

Ive also decided to replace Q101 &102; stamped RJK2017. They appear to be

http://www.digikey.com/scripts/DkSea...30135623916755

which I plan to order.

Anyone know what to use for D316? or a better substitute for RJK2017?

Thanks in advance to all the experienced fixers sharing your time!

[ReeceyBurger123]

Re: Pana TCP42C2 8 blinks SS Board components

One thing before you order any parts at all, have you checked the SN board for shorts ? These chained ERC so SS can cause parts on the SN to fail. Also you say it works intermittently ? If so Id start by resoldering the gorund pads on the SS and the legs of the transistors the joints on them look shit.

[flocko]

Re: Pana TCP42C2 8 blinks SS Board components

The SMD diode marked 83 are 1A 400v fast rectifiers. I use a Fairchild ES1G as a replacement, these are also used on LG + Samsung Sus boards. so always in my parts box. and are easy to find if you do not have them

[steves7839]

Re: Pana TCP42C2 8 blinks SS Board components

One thing before you order any parts at all, have you checked the SN board for shorts ?

When I opened the TV I found one of the SN-to Panel ribbon connectors had worked loose.

[ReeceyBurger123]

Re: Pana TCP42C2 8 blinks SS Board components

Right resolder some joints on the SS on the parts they look horrid.

[dick_barton]

Re: Pana TCP42C2 8 blinks SS Board components

The panel screw shown in picture 4 looks like it needs to be tightened down, so best to check all screws.

[ReeceyBurger123]

Re: Pana TCP42C2 8 blinks SS Board components

The solder joints on Q101 and 102 look very bad.

[steves7839]

Re: Pana TCP42C2 8 blinks SS Board components

I have replaced Q101, Q102 with RJP60D0DPE (600V 45A 122W IGBT) and D316 with ES1GFSCT-ND (diode Gen Purp 400V 1A SMA) from Digikey.

With a new cheap chinese hot air station in the hands of a newbie, I replaced these but displaced several other TINY resistors in the area behind Q101-Q102. I placed them back where they appeared on the board, and they ohm or diode check as they should.
On the power-up test, the TV now shuts down immediately, showing a brief flash on the panel. Drains of Q101-Q102 and Ve TP reach 124V before shutdown. The anode of D318 -IC304 pin 5 reach 185V as does Vsus.
The new Q101 and Q102 in diode test appear shorted G-D and G-E in circuit. Ve and Vsus ohm over 200K to board ground.

After close compare of the board with the SM schematic, I just realized R102 and R104 were returned to each other's position.
So my only question for the forum is; for Q101 and Q102 to measure a short in circuit is normal or a fault?

[tw2005]

Re: Pana TCP42C2 8 blinks SS Board components

Steve, I could insert a few expletives here and there so feel free to use your imagination.

We all have our share of moments doing SMD work, I lost a SMD resistor off this very board myself and sent me off in all sorts of directions. You could read it and get a giggle.

Anyway, Shopjimmy can be a very good source of high res images for comparisons, good place for you to start.

But I'm giving you the gong award for replacing the 2, RJK2017 N Channel 200V 45A MOSFETs with a 600V 45A IGBT!

Back to the desoldering incident.

The resistors R102 & R104 are totally misplaced. Note position and orientation is vertical not horizontal

Normally it's the RJP30E4 x 4 that short out on the SS

Without reading the whole thread what else have you replaced?