Panasonic TH-42PZ77U SC board repair 7 blinks

[johnboy1313]

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

Looks like it's working!

[tom66]

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

Nice, another one fixed.

[johnboy1313]

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

Well, I got it all back together and the bottom half of the screen is dark again. Upon closer inspection, it looks like only half of the lines on the bottom half of the screen are being driven. I guess I'm in the market for a new SD board.

[tom66]

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

No, you have a loose ribbon on the SD to panel connectors. A single loose ribbon on any connector causes the screen to interlace.

[johnboy1313]

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

I tried reseating the ribbons. No luck. It's like every other line of pixels is missing. One of the ribbons was in crooked last night and there were black bars across the screen. I noticed that the top pin on the sd board has come loose again. Now that I need it to, I can't get the plastic connector off of the board to try to fix it again.

Will just swapping in an SD board from the auction site fry my SC board?

[tom66]

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

I've had this exact same problem on the TH-42PZ70BA (basically the same board but UK version with digital TV etc.) Just make sure all the connectors are secure. It's not the SD board, it's the connection going to it.

[johnboy1313]

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

Even with the top pin on the plastic connector no longer connected to the board? I will definitely keep trying to at with the connectors, but lets say for a second that the board is physically damaged. Can I swap in an SD board without damaging anything else?

[tom66]

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

Yeah, I made that mistake too -- the connectors are easy to pull off the board. I secured it down with some glue which worked. Then, I fried the SD through entirely an unrelated accident (involved a small fried insect) so I replaced it. I can't see any risk in swapping the SD. I had no problem.

[johnboy1313]

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

Is there any difference between an SD board and a 1SD board?

[johnboy1313]

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

I was never able to get the bottom half of the screen to look good so I went ahead and bought a used SD board via the auction site. Remember, I accidentally pulled a pin from the original board and couldn't get it reattached. I got the new board installed this morning and had black bars across the lower half of the screen that I couldn't fix no matter how many times I tried to re-seat the ribbons. I finally used my meter and the new board to find where the damaged pin on the old board would be connected. I ran a jumper from the damaged pin to that point on the old board, reinstalled the old board and powered the set up. The set seems to be working now. Should I put a dab of hot glue over the exposed end of the jumper or do you think it'll be OK?

[tom66]

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

Back to the Future? nice taste.

Anyway, I would recommend it, but only to keep the wire in the right position.

That area of the board isn't isolated so perhaps it's not as critical.

[johnboy1313]

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

Back to the Future? nice taste.

One of my all time favorites.

Anyway, I would recommend it, but only to keep the wire in the right position.

That area of the board isn't isolated so perhaps it's not as critical.

I soldered the end of the jumper to one leg of an IC. I tinned the end of the jumper and used that little bit of solder to make the connection. There's really not much holding the wire on. It might be best to glue that thing down. Thanks for the input.

[johnboy1313]

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

Glued the jumper down and got the rear cover put back on.

[tom66]

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

This was one of Panasonic's first 1080p plasmas and the TH-42PZ70BA that I repaired is still my all time favourite for a TV.

When I kit out the student house I'll keep a close eye out for a similar model as it's a single FET usually which is really simple to repair.

[johnboy1313]

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

Yeah, when it was all done, I had $56.71 into it. Not counting the extra FET I bought (that will be sold on the auction site) and the second SD board I bought (that will be returned). Not a bad price for a 1080p plasma.

[tom66]

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

Aside from a slightly higher black level and higher power consumption, there's very little between this TV and a newer Panasonic model. The colour and clarity of the particular display always stood out to me. This model is also much brighter than newer models, which are restricted to meet energy saving legislation.

[octagon]

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

I had pretty much the exact same problem as johnboy1313 and rayrod81 with the SC board in my TH-42PZ77U. The FET that was bad on mine was Q646. It was Q641 on rayrod81's and Q643 on johnboy1313. I lifted both the S and G pins on the FET and the TV then worked so I know it's just the one FET. Thanks so much to both of you for all the detail in your posts.

However, I did some minor physical damage to the SC board in my keeness to troubleshoot so a new (or refurbished) board may be in order after all. I'll try replacing the FET first though. When it's fixed I'll repost.

[Zoea]

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

I'm testing those 7 fets later today when I get a multimeter. Got 3 replacements ready to rock - hoping to be up and running later

Anyone managed to find and update their firmware though, and if so, please give me a walk through !

[tom66]

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

There's a "firmware upgrade via the SD card" guide in the service manual.
http://www.tgohome.com/ServiceManual...&Search=Submit

[octagon]

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

As a follow up to my above post, I finally managed to get my SC board replaced today in my TH-42PZ77U. I physically damaged my initial SC board (a frustrating accident I won't get into), so I got a new SC board off the auction site (I guess you can't name the site here for some reason, but it should be obvious) for $125 including shipping.

It was supposed to be a working board, but unfortunately it came with the exact same problem I was having with my initial board! So I ordered in a new FET (Panasonic part number B1DFKM000002) for $15 including shipping from the auction site, and got a more experienced person to find and replace the bad FET (it was Q649 this time). The person I got the SC board from then refunded me half my money, which was very good of him considering he sent me a non-working board.

After I replaced the FET I powered on the TV and it worked! I then updated the firmware using this website:

http://www.panasonic.com/announce/up...tv/service.asp

After you enter your model and serial number it gives you the firmware to download as well as instructions on how to do the update. Very easy and straight forward to update the firmware.

Thanks again to everyone who contributed to this thread and helped me fix the problem!