JVC JLC42BC3000 screen froze on "JVC" logo.

[Davi.p]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

sadly this forum's message "token expired" really breaks the balls, i have lost a long message,
i say only to check for bad solderings on the new caps and check if them are low esr. The ripple seems that create problems to the reading of the nand flash..

[NewAtThis]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Update on the stuck-on-JVC-logo problem: Davi.p, I have checked the soldering and the ESRs of the new caps. All OK.

As I mentioned earlier, I had given up trying to fix my main CB and ordered a "new" board from Ebay seller, who claimed that the board was removed from a working TV with broken screen. Well, the CB was shipped in an envelope, instead of a box! Most caps were bent badly. The seller sent me a prepaid label to return the CB and have it replaced. I asked that the replacement CB be shipped in a box. It was shipped in an envelope again and, surely enough, it arrived with damaged parts. It also had the stuck-on-JVC-logo problem! So, I have just returned it for a full refund -- waiting for that.

Altogether, back to square one: looking for a way to fix my own main CB, assuming that that's where the problem is. A local repairman, without checking my TV, says it's an EEPROM problem and can be fixed for ~$60.

Please, forgive my ignorance: I have been assuming that the EEPROM and the NAND Flash are two different components. Is that right? Or are they one and the same thing? If they are different, which is which? Which is the one with the 48 pins and which the one with the much smaller number of pins?

Many thanks for any helpful response.

PS. Yes, my session also timed out and I had to reconstruct this posting. I wish that the person who maintains this very useful site changed those settings.

[Davi.p]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

EEPROM it's a generic term, it means a memory that is usually only read but written once, let's call it a bit obsolete term, it means a non volatile memory that can be erasable by software. Usually small size nvram are referred with eeprom and big size ones as flash memory, but it's not the truth. NAND flash is one type of flash. etc etc etc... The only way to drive to find the fault is to connect a serial port of a pc to the tv, and check the log. This is for experienced person. But if you're famailiar with Linux the task is not so far difficult. The other way would be change the flash but it's not for you so i don't mention.

[NewAtThis]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Davi.p, Sorry for not seeing this earlier. I used to get an email message whenever something new would be posted, but I have not gotten any for this! Thank you for the reply. I can connect the TV to the serial port of a PC running Windows (either XP, or 7, and maybe 10). Will that also give me an informative log file? If yes, will the file come up automatically, or will I need to issue any commands in a window that may open?

Could you, please, clarify: Is the EEPROM for this JLC42BC3000 TV the square component that has 8 connectors, or the larger on with 48 connectors (24 on each of two opposite sides)?

[NewAtThis]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Davi.p, I guess a better question than my last one would be: what is the label on the main CB for the EEPROM? And is it on the top or bottom side of the CB? That would certainly identify it uniquely and clear my confusion.

[nomoresonys]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Looks like U12, it's on the back side of the board, is that it?: https://www.ebay.com/itm/1pc-NAND-FL...UAAOSwM0ZbTrrQ

[Davi.p]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I have forgot, what i wanted to.say is that the technician was speaking about the big one, the nand flash on the bottom. If you can find a programmed chip and a so much friendly technician that agrees to.change the chip then you'll probably solve. Sorry i don't read back all the posts, but if you don't have done it before, you can do a settings reset by unpulling the power cord, short circuit the 8pin eprom on the pins 5,6 or 4,5 or 5,8 then plug the power cord then remove after some seconds the short.

[NewAtThis]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Thank you nomoresonys and Davi.p. I did try all the tricks suggested in this forum. Nothing worked. I even replaced 6 electrolytic caps, although they were not really puffed up, but their tops "might" have not been perfectly sealed when viewed with a magnifying glass. Still the stuck-on-JVC-logo persists.

I showed the U12 EEPROM on the main CB, which has 48 tiny pins, to the local repairman and he changed his mind. He said that he thought that the EEPROM was similar to others he was familiar with, which had only 8 pins. I saw a youtube video on how to desolder and solder a similar EEPROM, but I do not have that much experience with soldering to do it myself. So, I am back where I started -- although I learnt a lot in the meantime...

[nomoresonys]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I think if you get the part U-12 and take it to a trusted electronics or tv shop, it's like a 15 minute job with proper tools and solder paste etc. Maybe call ahead and describe it. They shouldn't charge too much less they be crooks.

[NewAtThis]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I'll make some local calls and see what I find out. I saw the EEPROM sold for ~$30 as a kit with 2 caps. Thank you again, nomoresonys.