whole new repair / learning world... plasma! Yikes!

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

Good luck!
I usually cut the legs and apply solder to the back of the IGBT and i use a 60w solder iron , works perfectly.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

yikes again !.... :-( so I did the attempt to remove the igbt's with a 50watt iron. I might not have had the iron on a particular contact / leg long enough along the way and it seems like I may have removed the contact pads during the operation on a couple of igbt's :-( I don't see where they "disappeared" to as they don't seem to be in the solder that was on the legs (and not on the iron). :-( I was able to remove the ibgt main "sink" as shown per the suggested posted video. So I am now trying to figure out how to "remake" lost pads / contacts for at least two and maybe three... Gates on Q423, Q422, Q402. I guess I used too much strength and not enough heat / time. :-( Is it right to assume that these lines are relatively low current and hence very thin. I should have probably attempted some "sucking" instead "heat / lift".

I hope that I can run some form of "track" to the "subtending" feed resistor.

Oh well, challenges are good... :-)

[tvtimmy]

Re: whole new repair / learning world... plasma! Yikes!

I add new solder to the legs and then use my iron to pry up. You should be able to fix the traces with some wire and creative soldering.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

Still just thinking about this as my soldering / desoldering "techniques" need some further practice... :-) But I checked the removed components (off board) and found that perhaps I over did how much I had to remove as the diode packs seem to be ok while 1 of the 4 30f131's seems to be alright also. I guess "in circuit" testing may have provided "less than good" checks due to the nature of the circuit / shorts. Lesson learned: be a little more "wise" before brandishing the soldering iron... :-)

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

Got a picture of the damage? Most pads go to the little resistors.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

here is a picture of the removal "work"... :-)
As you indicate, with a meter, I can find the "contact point" of the "residual pad trace" and follow it to the SMD resistor for the mosfet. Hopefully, I can solder a small wire section to complete the path for the new mosfets. I seems to have compromised one contact on d401... even thought pad looks good, it doesn't "trace" over to the side... this one might be tougher to fix.

One question: do you "pre-tin" the base of the mosfets before trying to mount them?
Thanks for the guidance.

[tvtimmy]

Re: whole new repair / learning world... plasma! Yikes!

No I dont. I solder down the pad and then the legs with no flux.

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

As Timmy says. Just solder the parts to the board and use the solder to drag a pad to the resistor.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

well I got things soldered to the board.... not the prettiest effort (I am a "resistor only man" myself...:-) ) but checked all the connections to the appropriate points off the various replaced components. Everything meter checked fine... hopefully the "electrical capacity" of all the connections is up to the task.

I am somewhat concerned about the fgd4536's in terms of their position on the ground pads. Because of their smaller footprint (compared to the 30f131) and the need to reach the other contact pads / legs, the bodies of the fgd4536's aren't fully on the ground pad. Hopefully, this won't be an issue.

SO... I guess the moment of truth is close. Any last checks needed before this things gets connected and powered?

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

:-( Well... I got the dreaded "snap" when I went to power up the set. It took out the q423. Could be my soldering was poor but more likely my check of the overall system were not done properly and there is a further issue down from the SC board.

So its back to the drawing boards and start over with the board check to confirm their state along with some more reading on the diagnostic steps.

I am not sure that I checked the SU board... or even how to check it?

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

I did some more check of the SC board. I thought at the time that I had checked all "three legged" components but I guess not... although maybe inboard testing might not be totally adequate. I found Q601 shorted along with one leg of q600 shorted.
BUT worse all, there is a "burn mark" at r600... which I assume is the "snap" I heard... :-(

Q601 is a "r5007 anj 107" and Q600 is "C08N25" (I think .. "0" could be a"D"). Can't tell what the R600 is (blown top portion).

Not that I have seen these parts replaced / mentioned in my travels / reads.
Hopefully they are available from somewhere.

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

Good try but unlucky! The exploded resistor is due to fake parts. There are fake FGD4536TM on ebay also. So i hope you got the right ones.
These bangs happened to me also when i first tried to repair the Panasonic plasma tv's. I tried it many times before i figured out i used fake 30F131/RJP30H2A. Trust me , i builded these boards almost from scrap and i know what parts blow with fake parts.

First of all a quick learning lesson. The IGBT's on these board are divided into 2 area's. The top area closer to the buffer boards are only shorted when the panel or buffers are shorted. Usually you dont need to replace DAF30.

The lower part of the IGBT's in the same line as RF1501 are shorted due to the ground/screw issue.
9 out of 10 times there is no need to replace RF1501 or RFN10 , they read short because the fets in the same trace are shorted. Same for DAF30.

On this board you only need to replace Q403/402/423/422 and Q451 and another one i dont see on the picture. It is located top right of the board and it is a D302 or 301.
You can use FGD4536 in place , well i read it somewhere on this forum. Never tried it.

You need to replace IC502 it is a BD8693FVM. That's the control IC.
You also need to replace Q531. 3Y (SMD Code) is a CPH5524-TL-E

Because the resistor blew you need to measure "Q661?" , it is located bottom left on the board , near the SC20 connector. It is a RJP63.....

What is the exact model of the board? I think i got this board somewhere so i can give you the resistor value. Should be a diode near , measure it.
Dont worry , we will fix the board but you need good parts!

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

thanks for the guidance. I guess "fake" and "marginal" are possible but not sure I would know the difference between real and otherwise. The other three survived.

Anyways, I got one more spare and also a few 30f131's to try... maybe although that might mean further disaster if they are "fake".

The board is tnpa5351am. I see the q451 (its dg302). I think the R601 is a 102 (1k)... based on shopjimmy and my eyes / screen.

Sorry but I don't see any "300" type numbering for the components... so I am not sure about the D302/301 item. The "D608" is in the area of the "issue".

Further: I think you mean Q601 (near the R601 that was blown). The FET is shorted.

I see ic501 and q531... yikes they are small, not sure I can do that work. Is it possible that they are OK? and that the failure was more to do with other issues (fakes or otherwise) ... kits don't appear to replace these.

the learning continues...

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

There is a good chance the IC501/Q531 are bad , the 7 blink would after repair go to 6 blink.
With 300 i meant the DG302 , they need to be replaced also.

The FGD4536 look different from mine , i will take some pictures of my parts.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

On the "7 blinks going to 6" perhaps... but would that not be IF other components that were shorted (ie. Q601, Q600) were replaced. My concern with trying to replace those "really small" components is my success at that skill. I have seen some threads where people have only done the "obvious" (the mosfet Q's as mentioned) Anyways, I will think on it some more.

On the FGD4536 looking different... don't know... different how? Weird!

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

moreno83... if by chance your board is the same / similar, can you confirm the r601 as being a 102... hopefully I can replace it with a normal resistor as I don't have any smd components / resistors.

I have removed q601 and q600 and confirm that they are shorted (q600 was dsg while q600 was ds). checking the board between gates/source/drains indicate no more shorts.

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

I will see if i have this board.

Could you please use some alcohol or nail remover and see if you can wash off the logo/marking on the FGD4536TM? Same for 30F131.
On a good part the logo wont "disappear."

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

ok.... thanks. Will try the "wash reveal" to see what's up. I have ordered the "boat" on parts but hopefully the mail service is faster than parcels.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

well the nail remover makes them cleaner but the printing is still there. I hope that this means that they are hopefully "good".... of course, not a guaranty since "marginal" is probable still a likely outcome with the "off shore sourcing". I suspect some of my problem might have been two fold. First, I should have isolate the sc board from the rest before powering (as I have read) and two, should have triple checked all three legged large scale components at the very least. Hopefully, I have tracked down all the shorted components.

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

That is probably a good thing. Does not have to be the FETS that are fakes , maybe you got bad diodes or bad soldering.

The resistor is 1ohm resistor.
I got the TNPA5349 board but the basics and components are all the same. On my board its R601 and is labeled as 1R.

Please remove all the shorted fets from the board and use the original DAF30 / RF1501 and RFN10.
When you have removed every part please measure Q661 , it is a RJP63G4. Is it shorted?