JVC JLC42BC3000 screen froze on "JVC" logo.

[Langston]

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

I found one for sale-
https://secure.m.newegg.com/ShoppingCart
Is it a simple de solder and re solder? How do I program the nand flash? Thank you!

[Langston]

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

ISTM that the NAND flash IC would contain the firmware for the TV. Therefore you would need to copy its contents.

If the problem is indeed the flash IC, then ISTM that it may be affected by bad blocks. One way to recover from this would be to update the firmware, but that would require access to a factory utility.

Edit: AISI, the NAND flash contents would be copied to SDRAM at bootup, and program control would then be transferred to the code in SDRAM. The SoC would not need to access the NAND flash again until the next boot. This means that the TV should keep running without issue after it has booted. If this is indeed what is happening, then that would point to the flash as the culprit.

Once I freeze the NAND and boot the tv it works properly until I turn it back off.

[fzabkar]

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

ISTM that the NAND flash IC would contain the firmware for the TV. Therefore you would need to copy its contents.

If the problem is indeed the flash IC, then ISTM that it may be affected by bad blocks. One way to recover from this would be to update the firmware, but that would require access to a factory utility.

Edit: AISI, the NAND flash contents would be copied to SDRAM at bootup, and program control would then be transferred to the code in SDRAM. The SoC would not need to access the NAND flash again until the next boot. This means that the TV should keep running without issue after it has booted. If this is indeed what is happening, then that would point to the flash as the culprit.

[Langston]

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

Nand Flash.

Were you able to do pin point cooling?

Thanks, I'm doing my best to try and only cool the Nand flash. I taped the surroundings off but i'm sure its not 100% pin point. If I purchase a Nand flash is it a simple re-install or do I need to load it somehow with info? Sorry I'm very new to electronics.

[budm]

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

Nand Flash.

Were you able to do pin point cooling?

[Langston]

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

That looks like to be switching power supply or switched Power MOSFET, and those two are the filter caps, they look like to be 22uF 16V.
Can you read the P/N of that 8-pin IC?

I detached the board and looked underneath to find this HYNIX SEMICONDUCTOR H27UAG8T2BTR-BC. I sprayed it with upside down air can and sure enough it boots up as normal. Any idea if these are available and if so are there any special instructions for installing or is it just a desolder and re-solder swap? Thanks for any help! Much appreciated.

[budm]

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

That looks like to be switching power supply or switched Power MOSFET, and those two are the filter caps, they look like to be 22uF 16V.
Can you read the P/N of that 8-pin IC?

[Langston]

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

Usually the bad cap will have high ESR when it is cooled and the ESR will go lower when it is heated up.
So right now it is a matter of pin pointing the bad part/s which is not easy when the board is crowded with parts.
There are parts on the bottom side of the board also.

I've attach a picture and circled the spot where freezing temporarily fixes it. I also noticed there are two aluminum electrolytic capacitors in the circle CE15- "14.4" and CE24 "3.1" both caps say 14 220 16s on the top.

[budm]

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

Usually the bad cap will have high ESR when it is cooled and the ESR will go lower when it is heated up.
So right now it is a matter of pin pointing the bad part/s which is not easy when the board is crowded with parts.
There are parts on the bottom side of the board also.

[Langston]

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

U18 (80-PIN IC), what is the P/N as printed on the top of the IC?
CE39 is the SMD lytics cap.

Thanks, I've isolated and sprayed U18 with no luck. Im very new to this and am not sure what the IC is. Could it be a bad SMD capacitor reacting to the cold?

[budm]

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

U18 (80-PIN IC), what is the P/N as printed on the top of the IC?
CE39 is the SMD lytics cap.

[Langston]

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

I wonder if the HDMI chip is locking up the processor. How hot does the chip get?

Thanks budm, Which is the HDMI chip in the picture you provided from shopjimmy? Also what is the round (capacitor??) CE39?

[budm]

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

I wonder if the HDMI chip is locking up the processor. How hot does the chip get?

[Langston]

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

an eeprom MAY work again if cooled good enough. That trick doesn't work on every eeprom, but it does work on a large percentage. You can apply that trick too on a bad eeprom that you want to read out and then program a new eeprom with the retrieved data. So you don't need to go ".bin" hunting.

I've isolated the area to this corner of the board near the HDMI inputs. Still can't pinpoint the exact problem. If I freeze individual components it doesn't boot but if I freeze the whole corner it boots and works properly. Any idea what component would be fixed by freezing on this corner?
See attachement-

[CapLeaker]

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

an eeprom MAY work again if cooled good enough. That trick doesn't work on every eeprom, but it does work on a large percentage. You can apply that trick too on a bad eeprom that you want to read out and then program a new eeprom with the retrieved data. So you don't need to go ".bin" hunting.

[Langston]

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

try to freeze the eeprom (can of air upside down) and turn the TV on. See what happens...

Your on to something! I first tried freezing the eeproms (or what I think are the eeproms) and no luck so in frustration I sprayed the entire board plugged it in and the logo went away and it went on to "no signal" and worked perfectly. I used the power off button and it turned off normally. No again it is stuck on the Jvc logo. I tried to isolate the problem by freezing in sections and trying to turn it on but no luck. What could this mean? Thanks!

[CapLeaker]

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

try to freeze the eeprom (can of air upside down) and turn the TV on. See what happens...

[Langston]

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

I was able to talk to Ablemantv but as suspected this is how they make a living and he is not willing to tell me the solution. Also they do not sell an eeprom for this tv. I really don't want to give up but Im running out of options..

[vinceroger69]

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

not that i know of? they store user data etc, so come pre programmed etc although some times you can re programme them yourself.

[Langston]

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

maybe send these a email see if they do one for your main board
http://www.ebay.com/itm/EEPROM-FOR-J...item3a814cdf0e

Thanks! I sent them a message this morning. Is it possible to test an eeprom with a multi-meter?