JVC LT24C340 Blue Led but no go.

[Turnip]

Hi Folks,

Have one in using SSB MSDV3222-ZC01-01 where it seems stuck in S/by. Tried disconnecting the Tact buttons but no difference - Maybe an Eeprom issue ? - Any thoughts - Chris.

[downunder]

Hi Chris,

Does PS-ON voltage present when you attempt to turn it on? Do PSU voltages come up if you force the PSU on?

Or am I trying to teach you to suck eggs?      -   Bruce

[Turnip]

Thanks Bruce,

First time I've met this 'everything on one board' set. Power supply seems basic with just 12v output with 5v and 3.5 v from Buck converters - All seem OK, even the M/Proc gets slightly warm and the DVD shuffles a bit at plug in.
First thought it might be leaky Tact buttons so isolated them trying use RCU for power-up - No dice so suspect that U6 Spi-Flash GD25Q64 might be corrupt - Read it for fun, full of stuff that means nothing at all to me - Guess a hopeful bin or a panel from the Flea - Seems plenty of panels about - Chris.

[Turnip]

Just an update,

Ebay panel sorted it - Thought read the SpiFlash from replacement panel - Might be useful - Chris.

[jellytot]

  Thanks for the flash dump Turnip. I had this same model tv that just displayed the jvc logo and then a blank screen and nothing else. Used an RT809f programmer to reflash, handy tool didn't have to remove the back cover.  Firmware looks like it got corrupted. 

[Turnip]

Nice one JT,

Checked around about the RT809f programmer and some folks can't suss how it works (Well I can't anyway) as seems info is mainly in Chinese.

A short course would be useful as great to flash corrupt Eeproms with the set back in place - Chris.

[jellytot]

Yes the chinglish is hard to follow and a real pain using google translate. what worked for me on this set not sure about other sets and models though.IT was relatively straight forward. you connect the RT809F using vga port on the tv. select the auto detect and up comes the micro and type of flash, select read and it takes a dump, likewise you just select file and write to spi flash. also if it locks you out it advises what to do i.e. short pins 3 and 8 of spi and select read or write and when it starts you can remove the short. This worked fine on this set  I have only recently got it so am still learning.  there is software in english for the programmer and seems to have regular updates.

[downunder]

Ironically I have just received a JVC LT40N530A where the red LED flickers as it turns on (this could be normal), tv comes on with the JVC logo screen, then it cycles between no screen and JVC logo for some time before it eventually fires up and works properly. Like yous, Chris, everything is on a single board. I suspect the eeprom but don't have a reader. Might have to check out the flea.                 

Bruce

[Turnip]

Hi Bruce, seems typical with Chinese JVC sets (and most other Chinese wonders)

Amazed though that a 40 inch could have a similar single board format - Guess LED's are really efficient even if they only last a year or two - Chris.

[downunder]

Further to this:

Was having trouble locating a supplier for this board, so I decided to cook it.

Unfortunately, the oven timer was out of action and I forgot about it, so it was cooking for around 1.5 hours.

All the electros had popped but I decided to try it anyway. Surprisingly it worked but the mains filter caps went up in smoke.

Changed all the damaged caps (9 in total) so now it's on soak test. Hopefully, sometimes you gotta get lucky.

Bruce

[murtagh]

Thanks for the flash dump Turnip. I had this same model tv that just displayed the jvc logo and then a blank screen and nothing else. Used an RT809f programmer to reflash, handy tool didn't have to remove the back cover.  Firmware looks like it got corrupted. 

Thank you..