JVC LT-40V953 standby light flashes and stays on but no picture

[filippia1981]

Hi I have to solve an issue with a JVC LT-40V953 that when switches on the standby flashes 10 times and then stays on but I do not get picture. I have checked the backlight with backlight tester and they are ok. I have replaced the PSU card with new one but still the same issue.

I think it is the EEPROM that need flash but I can't find the bin file for that tv.

I don' t know if I m right. Can someone drop me an idea what should I check and inform me where can I find the bin file?

kind regards

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

I have replaced the PSU board with a new one. I can post pictures and a short video with the issue but I do not know how to post them

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Attach pictures of the whole backside of the tv, to see how they are all connected and of each board, does the tv have a stand alone tcon board? If so test that you have probably around 12 volts on each side of the fuse on the board, black probe to metal chassis ground, if you haven't already.

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Tomorrow I will upload more photos from all tv boards. I have checked the t-con board fuse but not getting the 12V

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

You tested it as in this video, correct?: https://www.youtube.com/watch?v=iuHrnvAKlGw

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Here's another, see if you have those 12 volts there on the LVDS ribbon cable, if not check those components he's checking on the mainboard: https://www.youtube.com/watch?v=ocqnqmBxiqY

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Should have said 12 volt coming from the ribbon cable there by the connector where he's checking.

[arizanotlari]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Not same model, for testing : https://yadi.sk/d/tY8HSS_8Z0a-0Q

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

My mistake. I measured the 12V at the T-con.
I cannot upload the photos. it does not upload the photos

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

The URLs from my google drive are:

https://drive.google.com/file/d/1iXi...ew?usp=sharing


https://drive.google.com/file/d/1iCZ...ew?usp=sharing


https://drive.google.com/file/d/1i70...ew?usp=sharing

https://drive.google.com/file/d/1evS...ew?usp=sharing

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

1

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

5

[R_J]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Monitor the voltage ACROSS the black and white wires going to the led's when the tv is first turned on, Does it go up to about 160v then drop down?
You could also check the voltage at D504 when the tv is first turned on.

Also check if you have BL_ON-OFF voltage (3~5v)

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

So are the backlights on with no picture showing or are they off?

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

BL_ On-Off 3.3V

LED connector 72V and dropping (Voltage across black and white)

D503 voltage 172V and dropping (D504 does not exist on the board)

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

When I switch on the TV standby flashes 11 times and then the standby stays on constantly. No picture, no backlight, no response to remote, no sound.

What I have noticed today is that after the 11 flashes the backlight flashes once and then nothing

[dick_barton]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

BL_ On-Off 3.3V

LED connector 72V and dropping (Voltage across black and white)

D503 voltage 172V and dropping (D504 does not exist on the board)

Check the black wire to chassis voltage and then white to chassis looking for the peak voltage at switch on.

It is looking like a probable led or led connector fault

[nomoresonys]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Indeed, then unplug backlight connector and test for around 400 volts at the big 450 VOLT filter capacitors, check in standby which is plugged in but off then check when powered up, meter set at 200 or 600 vdc meter probe on each leg, be VERY CAREFUL only touch it with the meter leads, 450 volts CAN EASILY KILL. Don't do it if you are not comfortable with it.

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

Indeed, then unplug backlight connector and test for around 400 volts at the big 450 VOLT filter capacitors, check in standby which is plugged in but off then check when powered up, meter set at 200 or 600 vdc meter probe on each leg, be VERY CAREFUL only touch it with the meter leads, 450 volts CAN EASILY KILL. Don't do it if you are not comfortable with it.

Because I am from Greece, I got the part that I have to unplug the led and measure the 450V filter capacitors. I did not understand the rest of the paragraph what to measure

[filippia1981]

Re: JVC LT-40V953 standby light flashes and stays on but no picture

check in standby which is plugged in but off then check when powered up, meter set at 200 or 600 vdc meter probe on each leg

Because I am from Greece I did not understand that part of the paragraph. check in the filter capacitors legs when the tv is standby on but off and then when it powers on?