Hitachi 42HXT42U blue diode and restart

[Ralph Green]

Hi all.
I have this one to have a look. This is Hitachi 42HXT42U with Vestel 17IPS20 PSU. It will powers up, logo shows up, than it goes to black screen standby diode blinking orange/blue. After few seconds goes off for few seconds and all will starts again. Any ideas what is wrong whit this TV?

I can get PSU but I need to be sure that the PSU is failing.

[tom66]

Re: Hitachi 42HXT42U blue diode and restart

Worth checking voltage on PSU primary side, across 450V cap.

[Ralph Green]

Re: Hitachi 42HXT42U blue diode and restart

Can you tell me where is this cap please?

[tom66]

Re: Hitachi 42HXT42U blue diode and restart

Top of board, two large caps marked 450V. Check across either. Careful, mains voltage, high voltage, potential for shock.

[Ralph Green]

Re: Hitachi 42HXT42U blue diode and restart

392V on both.

[tom66]

Re: Hitachi 42HXT42U blue diode and restart

Ok, check the voltage to the LED string (single pair red/black), and the lower voltage rails, 12V/24V/etc.

[Ralph Green]

Re: Hitachi 42HXT42U blue diode and restart

165V to LED

There is no marks on PCB with voltage value. Is there any diagram available for this mode?

[tom66]

Re: Hitachi 42HXT42U blue diode and restart

If the LED backlight comes on, the LEDs are probably ok. You should check if the voltage remains steady though, or if it drops/increases, as the backlight flashes.

I don't have a schematic for this but there are usually ones available for Vestel sets.

[Ralph Green]

Re: Hitachi 42HXT42U blue diode and restart

Just checked voltage with backlight on.

[Ralph Green]

Re: Hitachi 42HXT42U blue diode and restart

Sorry guys but I need to fix this TV. What should I buy? PSU or Logic board?

[mahcin]

Re: Hitachi 42HXT42U blue diode and restart

Hi,
I have similar problem,
any one can help please?
Red standby light is flashing all time, TV turns on for about 10secs, then off, and on again...and again.... when start up, I have 170V on LED socket and is quick dropping to 142V, and when is switching self off then 100V

checked 450V caps, and only about 60V there, checked all diodes (outside board), checked both 450V caps (outside board)

still unlucky, could it be transformer?

[mahcin]

Re: Hitachi 42HXT42U blue diode and restart

I'm getting 3.3v/5v/12v/24v so it has to be live problem, I think, if I disconnect LED socket, then is constantly ON without restarts

[promo7uk]

Re: Hitachi 42HXT42U blue diode and restart

RED / BLUE STANDBY LIGHT FLASHING = software fail.. u10 & u13 i believe,, i have loads fo firmwares for these,, but prob is you need NBoot file. model of board + screen model and serial. to pair them. right pain in the arse, ive got one at the minute akk voltages completely dead,on mainboard..

nboot is file that boots tv,, normaly when crappy apps added to tv causes tv software / firmware to fail.. www.ohmsupplies.co.uk try him he does firmware to fix it on either usb or via email. and these come with nboot.

or you can try this on vestel.. put on usb formatted to fat32 then once inserted in tv and u press stanbdy press ok on remote straight away keep it pressed till red/blue led speed up flashing once this happens.. wait ,, hopefully it might fix your issues.. ive done a fair few like this ,, but more serious cases you need the nboot from ohmsupplies.

Vestel mb82-2 firmware V.084 this is just basic firmware for MB82-2 mainboard and will not change bootloader aka nboot where your screen data is located ,,put this on your usb stick. and pop in tv, press power on , then press ok ,, wait lights should flash faster,, red/blue.. wait ,, till they slow down,, hopefully this may fix your issue.. hope this helps. if not msg me what mainboard you have il help u out as unshure on this model..

file is on my mediafire account,, hope this helps.
http://www.mediafire.com/download/53...ware_V.084.rar

also worth checking

D214 D215 THEY CAUSE BACKLIGHT ISSUES, AND C525 1UF 50V ALSO.. WORST CASE, LED DRIVER CHIP TPS61199 3£ OFF EBAY

###############
http://electronicshelponline.blogspo...-software.html
http://www.gmfok.com/firmwares/tv/vestel.html
also more here,, make shure screen is correct else once flashed ,, could screw up viewing,

[ReeceyBurger123]

Re: Hitachi 42HXT42U blue diode and restart

Thats for the info, however you dont need the exact firmware flash just the core update folder. I did the 40" version today, restaring all I had to do was reload the core update several times and fixed

[charley91]

Re: Hitachi 42HXT42U blue diode and restart

Hi have Hitachi 42HXT42U with Vestel 17IPS20 PSU and having reboot problem shows Hitachi logo then powers of and power led blinks red/blue put another working mainboard in set and still doing the same any help would be much appreciated.
Thanks in Advance

[charley91]

Re: Hitachi 42HXT42U blue diode and restart

sorry I replaced PCB board with working board

[ReeceyBurger123]

Re: Hitachi 42HXT42U blue diode and restart

Right understand that the Mb causes this.