42PFL7422D/37 Service Manual Needed

[PlainBill]

Re: 42PFL7422D/37 Service Manual Needed

What is the part number of the chip in the green box (above pic) that is connected to the heatsink?

I'm a little shocked that there is no fuse somewhere in the secondary circuit of that huge transformer.

I'd be shocked if there was. The transformer has an output voltage in the 1500 - 2000 volt range. The output current is probably in the 100-200mA range. That makes for a very expensive fuse.

PlainBill

[Ripsnort]

Re: 42PFL7422D/37 Service Manual Needed

Here are 2 pics. I see there are some inverter boards on ebay for this model. Must be a very common failure just with that little board.

By the way, thanks for the service manual. Seems to be the exact match.

Thank goodness for the internet!

I have the exact same issue. Same exact location of burned pin.

Is this an inverter board? I tried typing in the S/N on the back of the inverter board at B&D and it came back with nothing.

Where can I buy one of these? Thanks so much!

Edit: I typed in the wrong number.
The *right* number I believe is LC420WU5.

Did a visual inspection of all the caps and other boards, no buldging or leaks, and this part above appears to be the culprit.

Any input appreciated!

[Ripsnort]

Re: 42PFL7422D/37 Service Manual Needed

Pic and THANK YOU! Hopefully this will fix the problem.

[Dgtech]

Re: 42PFL7422D/37 Service Manual Needed

Well, If you do a search on ebay for the chip(bd9897fs), you will find multiple vendord selling it as low as $5 per chip. I just bought about 5 of them last week from a seller on ebay. I have seen this chip in a Philips set and a Vizio set. When I did the Vizio, it was nice to have an extra chip just sitting there. I removed it and replaced it within an hour. However, If you want to replace the board (LC420WU5), ebay sellers are selling this one for $120.

[Ripsnort]

Re: 42PFL7422D/37 Service Manual Needed

Well, If you do a search on ebay for the chip(bd9897fs), you will find multiple vendord selling it as low as $5 per chip. I just bought about 5 of them last week from a seller on ebay. I have seen this chip in a Philips set and a Vizio set. When I did the Vizio, it was nice to have an extra chip just sitting there. I removed it and replaced it within an hour. However, If you want to replace the board (LC420WU5), ebay sellers are selling this one for $120.

Thanks for the reply.
I ended up canceling the order for the mistake in the board I ordered. (Thought I was getting everything attached! haha!)

So, I did order the 2 inverter board kit. Plan on replacing both even though the 2nd shows no sign of duress.

I'm crossing my fingers that this will fix the issue permanently. I've never seen an IC chip blow on it own. Something else has shorted out causing that part of the chip to overload. Maybe I'll have to sell it fast like you did. (I was planning on replace my bedroom 37" LCD with this back up TV....)

[Dgtech]

Re: 42PFL7422D/37 Service Manual Needed

The kits you refer to have four of the smaller chips and one of the larger (32 pin) chips. If you read my post here, (#29)
https://www.badcaps.net/forum/showth...974#post129974
this will minimize what you need to replace.

[Ripsnort]

Re: 42PFL7422D/37 Service Manual Needed

Fixed! Thanks again all!

[Dgtech]

Re: 42PFL7422D/37 Service Manual Needed

For anybody attempting to repair this board, this attatchment is a procedure that was created by Philips for also modding this board. The mod is not needed to make the unit work, but should stop future repeat failures.

[Bleacher Bum]

Re: 42PFL7422D/37 Service Manual Needed

I have found a replacement board for 110.00
Is that worth it? Or am I looking at a simple fix with some capacitors and a transformer?

Foreveraltared - Did you buy a new board and replace it? I appear to have the exact same problem with that huge transformer. It makes this lovely shorting "crackle/zap" when the power is turned on. I'm wondering if I should just replace the board instead of troubleshooting further with the transformer.

[Bleacher Bum]

Re: 42PFL7422D/37 Service Manual Needed

Just a follow-up post for anyone who needs the information. I purchased a DPS-168EP board for $60 and replaced it. It immediately fixed the problem.

[Terryfictv]

Re: 42PFL7422D/37 Service Manual Needed

OK - I am obviously going to be a newbie to this... I have a 42PFL7422D/37 and I do not see an inverter board. I did find a T-con board, but where everyone else's pics show a panel next to the SSB, I have a flat surface. Could it be that my TV doesnt have an inverter? Basically I have the typical (or so it seems) Philips sound but NO picture. Any advice would be very much appreciated. Thanks so much!
B

What is inside a 42PFL7422D/37 depends on who made it & where....
LG or AUO ... Did you solve your no picture problem ?

I need some help with same model as yours.....

[PlainBill]

Re: 42PFL7422D/37 Service Manual Needed

What is inside a 42PFL7422D/37 depends on who made it & where....
LG or AUO ... Did you solve your no picture problem ?

I need some help with same model as yours.....

Interestingly enough, about 3/4 of the new people posting here need help. The other 1/4 are rejoicing because they found the information they needed, and wanted to help us.

Of the 3/4 who need help, about 50% actually give enough information in their first post to help us diagnose the problem. Some even attach useful pictures.

Some don't do so well. Depending on my mood, I will respond with sarcasm, humor, or abuse. A very few will be treated politely. Others will be ignored. This is not your lucky day.

Let's start at the basics. Is the TV plugged into a working outlet?

PlainBill

[Terryfictv]

Re: 42PFL7422D/37 Service Manual Needed

Let's start at the basics. Is the TV plugged into a working outlet?

PlainBill[/QUOTE]

Yes ! Plugged in ! After carefully hand-soldering the power / inverter board, I now have back light ! No video, audio OK on all inputs. Conclusion = bad T-con
PCB ..A parts supplier had it for thirty bucks ! Ordered today..# 55.42T02008 for
YA4 Chassis with panel T420HW01 v.4....( AUO = Chinese ).

I will post the final results....

Terry

[PlainBill]

Re: 42PFL7422D/37 Service Manual Needed

Let's start at the basics. Is the TV plugged into a working outlet?

PlainBill

Yes ! Plugged in ! After carefully hand-soldering the power / inverter board, I now have back light ! No video, audio OK on all inputs. Conclusion = bad T-con
PCB ..A parts supplier had it for thirty bucks ! Ordered today..# 55.42T02008 for
YA4 Chassis with panel T420HW01 v.4....( AUO = Chinese ).

I will post the final results....

Terry[/QUOTE]

You may be jumping to conclusions. It could also be a bad main board. We HAVE seen a number of TVs with bad voltage regulators on the main board. Still, it IS cheaper to replace the T-con than the main board.

PlainBill

[Terryfictv]

Re: 42PFL7422D/37 Service Manual Needed

Second main sub = no help , third main had 5 blink code = shorted 7B06 regulator !
Sent back for credit.....Proof in the pudding on this one ! TTYL

[Terryfictv]

Re: 42PFL7422D/37 Service Manual Needed

T-con not an issue.....re-soldered main board ( again ) and re-seat all connectors = FIXED ! Performed re-configure main board procedure and all
option codes checked ! Test ran many hours for several days = solid !

Conclusion = Solder power and main PCB's and clean / re-seat all connectors,
including both ends of LVDS Cable....

Be thorough to avoid re-call !

[panamajef]

Re: 42PFL7422D/37 Service Manual Needed

thank you all for your great information...I am ordering my boards now...120.00 on shopjimmy for the kit...I will try and get back to you with the results once I replace them...

[panamajef]

Re: 42PFL7422D/37 Service Manual Needed

again thanks to all of you and your great information...I pulled the Slave inverter board out and it was burned in the middle of the B989 chip just as many above had noted. I ordered the two board set from shopjimmy.com for 120.00 with no return fee (several places wanted 150.00 exchange fee) and replaced them both. The set fired right up. Thanks again!!!! PS, I am a RN not an electronics guy...your explanations and photos etc were extremely helpful and made the repair possible.

[PlainBill]

Re: 42PFL7422D/37 Service Manual Needed

again thanks to all of you and your great information...I pulled the Slave inverter board out and it was burned in the middle of the B989 chip just as many above had noted. I ordered the two board set from shopjimmy.com for 120.00 with no return fee (several places wanted 150.00 exchange fee) and replaced them both. The set fired right up. Thanks again!!!! PS, I am a RN not an electronics guy...your explanations and photos etc were extremely helpful and made the repair possible.

So when Jaime Sommers (The Bionic Woman) needs repair, she can come to you? Cool!!!

PlainBill

[panamajef]

Re: 42PFL7422D/37 Service Manual Needed

So when Jaime Sommers (The Bionic Woman) needs repair, she can come to you? Cool!!!

PlainBill

Bill, that was a flashback if I ever had one...thanks for the laugh!!! And yes she could come to me anytime!!!