Toshiba 55U5766DB LED TV switches off after approx 10 seconds

[nevillet]

Hi All,

I am trying to repair a friends TV which switches off after about 10 seconds.  I thought the problem might be the Vestel 17IPS72 PSU board and i've checked all the electrolytics and the diodes.  All are fine.

The Vestel logic board is a 17MB120.

Any pointers would be most welcome.

Thanks

[m3vuv]

i would start by checking the psu outputs firstly,ie see if they all vanish when it turns off.

[nevillet]

Thanks M3VUV,

It turns out that the psu board is OK.

I've figured out a work around to make it work:  After switching on you select an external source, like a video file on a USB stick. Once it is playing you can return to the TV tuner and it continues to work fine.  You have to repeat the process after switching off/on.

A bug in the firmware perhaps?  No updates are available on the Tosh site.  From new in 2017 it was fine and has only developed the issue over the last few weeks.

[m3vuv]

certainly an odd ball fault!

[KRISTOFFER]

I found the following after some research. Novatek manufactured the NT72563 chip. Vestel manufactured main AV boards fitted with this chip. Vestel manufactured televisions containing these boards. Toshiba, JVC, Bush, Polaroid, Logik, Luxor, Turbox etc sold the televisions with their own logo on and start up logo as their own brand. Even when set to automatically update software, they do not. In 2018 the original software was adequate for on demand channels etc. Two years later they still have the 2018 software and applications software resulting in them turning themselves off then back on again. At this point they will take all other devices connected to your hub out.

The Vestel boards fitted with Mstar MSD93F3PK2 do update and continue to work. No one is accepting any blame. IF you are lucky enough to get a USB stick from your manufacturer with a software update, it will not work.