Hisense H60N5705 automatically switches off

[_max_]

Hisense H60N5705 installed in a conference room, turns off automatically a few minutes after being switched on.

Problem occurred suddenly, during a video conference. Switched on again by the remote control, it continued to work for a while and then switched off again.

Power cable and HDMI cable checked.

No changes by connecting the TV to another source but, even if it is left on the OSD menu, it stays on for a few minutes and then switches off.

So they took the TV (a 60' which is not easy to handle) to the lab and asked me to check it.

I still have to open it up, but I don't have the schematic diagrams and should proceed by trial and error, although I imagine a problem with the power supply stage.

How do you suggest I proceed, since I don't do TV but RF ?

Thank you for any help,

[Diah]

1- be sure at the menu setting. automatic switch off are disabled.
2- reduce the LED BL level setting below 30% and check if it remain on longer
3- if 1 and 2 didn't bring change then check after connection cable reseated, joint solder crack at PSU

[_max_]

Thank you Diah for your reply!

1- be sure at the menu setting. automatic switch off are disabled.

Yes, this is disabled. As wrote, the issue appeared suddenly during a video conference. Never happened before and nobody changed TV settings.

2- reduce the LED BL level setting below 30% and check if it remain on longer

Ok, I will try this.

3- if 1 and 2 didn't bring change then check after connection cable reseated, joint solder crack at PSU

I guess I have to open it, even if I have no schematic diagrams...

[_max_]

Is there any place where I can find the circuit diagram of such TV ?

[EazyBone]

They aren't really offered to often anymore.

Did you check the backlight to see if it was good? Led tester?

[Andrew F. Ali]

Try resoldering the PSU.

[_max_]

Ok, thanks for your hints. I will try soon

[_max_]

I did not found any broker CAP in the power supply stage, nor burnt or open component:




In the CPU SMD board I did not found signs of hot parts:



With the TV is switched on, temperature of single components are in the range of 35-40 °C, only the radiator shield is close to 46 °C.

When the TV switches OFF, there is no noise or sparks visible.

I would proceed by replacing ALL the electrolitic caps in the PSU unit.
What do you think?

[EazyBone]

I think that's a waste of time and money.

Recheck the cracked solder joints as diah said. Test the Backlights with led tester if you have. Tvs will shut off when bl's fail. Google especially shuts down, Roku tends to keep going.

[lotas]

If the TV constantly goes into reboot or standby mode:
Disconnect the TV power supply and supply +12V from the power supply to the motherboard. Check the power-on.
If the motherboard stops rebooting or turning off (you can see it by the LED indication), then you have problems with the backlight.

[Andrew F. Ali]

Resolder the PSU especially the bigger joints even if the look OK. Start with the Transformer legs and Main Cap legs.

[_max_]

If the TV constantly goes into reboot or standby mode:
Disconnect the TV power supply and supply +12V from the power supply to the motherboard. Check the power-on.
If the motherboard stops rebooting or turning off (you can see it by the LED indication), then you have problems with the backlight.

It does not go in STBY "constantly" but "sporadically".
Difficult to supply 12V directly to the mobo, but I can try.

[_max_]

Resolder the PSU especially the bigger joints even if the look OK. Start with the Transformer legs and Main Cap legs.

Yes, good idea.

[Storyteller12]

Check backlights as everyone stated. If that checks out these Hisense with android are known to have a high rate of emmc failures

[nomoresonys]

Try to do tests and report results. Now what was the result of the tests in post #2??, you gave no result for #2, reducing backlight level. Even if you do the test and there is no difference report it, everything helps to narrow the problem down.

[_max_]

Try to do tests and report results. Now what was the result of the tests in post #2??, you gave no result for #2, reducing backlight level. Even if you do the test and there is no difference report it, everything helps to narrow the problem down.

In response to POST #2, there is no point in adjusting the brightness levels and there is no point in reloading the factory settings either.

Check backlights as everyone stated. If that checks out these Hisense with android are known to have a high rate of emmc failures

I don't have any specific tool to test the panel because, as already explained, I don't do TV repairs for a living.

How can I ‘check' the functionality of the panel or emmc failures?

[nomoresonys]

NO that is not correct, what IS correct is there IS NO point in trying to help some people, bye bye and welcome to my ignore list.

[Storyteller12]

NO that is not correct, what IS correct is there IS NO point in trying to help some people, bye bye and welcome to my ignore list.

Exactly, can’t ask for help and then tell us there’s no point in doing things we mentioned. There’s no point in helping if you can’t follow simple directions.

[nomoresonys]

Exactly, can’t ask for help and then tell us there’s no point in doing things we mentioned. There’s no point in helping if you can’t follow simple directions.

+1000

[CapLeaker]

Exactly, can’t ask for help and then tell us there’s no point in doing things we mentioned. There’s no point in helping if you can’t follow simple directions.

Gets my vote too.