Panasonic TH-42PZ77U SC board repair 7 blinks

[geinopolis]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

hi there,

i have had a th-42pz70e with 7 blinks. i changed a mosfet and it runs again.
i looked for the firmware upgrade on this website, but it seems that this tv is no longer supported.

@octagon

do u have the firmware still on your computer or can u remember how the file is called?

best wishes

sry 4 my bad english

[octagon]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

hi there,

i have had a th-42pz70e with 7 blinks. i changed a mosfet and it runs again.
i looked for the firmware upgrade on this website, but it seems that this tv is no longer supported.

@octagon

do u have the firmware still on your computer or can u remember how the file is called?

best wishes

sry 4 my bad english

I do still have the file. It's called "42FM10_v47.82t1_sddl.exe". As it's an exe, I won't be posting it here though.

However, the firmware is specifically intended for models TH-42PZ77U and TH-42PZ700UA. As it's not intended for your model number (TH-42PZ70E) it could damage your TV.

[Lukie]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Hi Guys,

I have noticed a lot of troubles with the SC boards around the internet.
I got a 42py70fa (comparable to a 42pz70) which has the same SC board as above. And after reading many topics and forums i chose the easy way out by buying a second hand SC board from an internet shop. However after installing it, and troubleshooting it, it looks like this one is broken as well!!
Really bummed out and not really wanting to spent more money, i am now reading up on replacing the fets. However i have no experience measuring these things.

So i tested all fets that are laying on the board, and i dont really know what to look for, since many people are experiencing problems with the fets Q641-Q646 i was hoping i would see a noticeable difference in readings, but i dont.

I did however find shorts (is this good or bad?) in the fets Q648-Q654 from the Drain to Source, but not in the other fets. Please see the attached pictures. Does this mean one of these is broke? Because i get the same problem with the "new" board as well.

Any help would be much appreciated!

[tw2005]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Hi Guys,

I have noticed a lot of troubles with the SC boards around the internet.
I got a 42py70fa (comparable to a 42pz70) which has the same SC board as above. And after reading many topics and forums i chose the easy way out by buying a second hand SC board from an internet shop. However after installing it, and troubleshooting it, it looks like this one is broken as well!!
Really bummed out and not really wanting to spent more money, i am now reading up on replacing the fets. However i have no experience measuring these things.

So i tested all fets that are laying on the board, and i dont really know what to look for, since many people are experiencing problems with the fets Q641-Q646 i was hoping i would see a noticeable difference in readings, but i dont.

I did however find shorts (is this good or bad?) in the fets Q648-Q654 from the Drain to Source, but not in the other fets. Please see the attached pictures. Does this mean one of these is broke? Because i get the same problem with the "new" board as well.

Any help would be much appreciated!

Short is bad. i don't know these well, how many shorted? Is it the whole bank? if the whole bank is short, you may have to somehow desolder and lift the legs up one ata time to see how many are bad.

The other guys within in this thread should be able to help you more.

try and get your money back for the other one of if you use paypal lodge a claim.

too many flogging boards off they can't, won't or don't know how to test.

[Lukie]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Thanks tw2005, that post helped me to understand more about a perhaps faulty fet. So i lifted up the legs and found out fet Q552 is bad.

Now Im trying to pry it off, and the two legs where easy, but is it even possible to pry the fet off with a 60W iron? And i know it has been said in this topic before, but heating the tab on de D side didnt get me anywhere in 20 minutes... any tips?

[tom66]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

For a quick test, you can fully cut the S and G pins, and the FET will be isolated so you can see if it will power up. I would use hot air to remove it. If you don't have equipment there are people offering a repair service.

[Lukie]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Thanks tom, so i found the bad fet... tried to remove it, with another soldering iron from a friend. And started to wiggle it a little to get the fet off... unfortunately, the solder didnt melt, but the glue of the board did. With the result that i pulled a piece of the board with the fet.
Now I am going to ask a silly question for some of you, but as you noticed i am pretty new to this...
Is this repairable? or can i throw the board away?

[SM-Piyes90]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Thanks tom, so i found the bad fet... tried to remove it, with another soldering iron from a friend. And started to wiggle it a little to get the fet off... unfortunately, the solder didnt melt, but the glue of the board did. With the result that i pulled a piece of the board with the fet.
Now I am going to ask a silly question for some of you, but as you noticed i am pretty new to this...
Is this repairable? or can i throw the board away?

You can recover it if you can track back the pins solder points , now even if you replace that fet it may short again , i would check that card very well . Capacitors specially

[tw2005]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

You should be a dentist, nice extraction.

I think one issue will be the fact that the copper pad is common to all the other FETs, acting as one whopping big heatsink which is why you're having trouble.

The only idea I have is to expose the mask around that, cut a piece copper sheet a little over size of the damaged area, epoxy it to the board but not to the exposed copper, then flow solder around the edges to make electricial contact with the exposed copper, and then hopefully solder the new FET to that.

It needs that pad for thermal relief.

That's my idea, never been faced with that big a pad torn. You're going to have to get the heat into it better.

[mrcasual]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Re,

I followed the instructions in this thread (thanks, everyone) and found 1 dead mosfet. However, there is another one that's not giving me any reading from the left leg. It's the only F6S703 on board. Is that normal or should I be replacing it as well?

Thanks.

[tom66]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

It's normal for a FET to show only one reading from the drain to source, everything else should test open circuit.

[mrcasual]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

It's normal for a FET to show only one reading from the drain to source, everything else should test open circuit.

Thanks.

[mrcasual]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Could someone please post the latest firmware? Thank you.

[mrcasual]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Could someone please post the latest firmware? Thank you.

After some "googling", here's the f/w v2.9 from Panasonic: http://www2.panasonic.com/webapp/wcs...&storeId=15001

[tom66]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

I think that's for the tuner, not sure if that fixes bug with control board firmware killing the FET.

[mrcasual]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

I sent @octagon a message but at the moment there's no other firmware to be found.

http://shop.panasonic.com/shop/model...s&support#tabs lists only 2.09

Please share if you have a newer version.

[Rockguy]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

Did anyone ever come up with this firmware? I've got to go through finding which FET is bad on my TH-42PZ77U

[Rockguy]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

For a quick test, you can fully cut the S and G pins, and the FET will be isolated so you can see if it will power up. I would use hot air to remove it. If you don't have equipment there are people offering a repair service.

Do you block off the area around it to protect everything else from the hot air gun or just let er rip?

[Rockguy]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

I had a similar experience. Can this be saved?

[Neelix]

Re: Panasonic TH-42PZ77U SC board repair 7 blinks

I think there was a post from somebody that explained how to repair damage like that, but I can't find the post