Hisense H55A6500UK backlight, sound but no display

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

Glad to hear it.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

So just a quick update on this to close it off!

T-con arrived and fitted and all working as it should be.

Thanks again!

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

To be honest I was already working along those lines getting a cap from a tcon I have lying around, matching size/shape/color but have managed to source a replacement tcon for £3 incl p+p so think I shall wait for delivery.
Bought a main too for £6.50 incl p+p but may not need that now! So for the cost of a tcon alone I'll have both in case they are needed.

A very BIG THANKYOU to all once again for contributing!!!

BRILLIANT WORK LADS!!!

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

Good to hear, not sure if it's best policy but there's a guy on youtube that looks around for a cap in his scrap boards that's about the same size physically and uses it, can also measure it with a multimeter I guess.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

I dared! And it powered up, panel looks good too, Yippee!!!

Powered if off quick.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

So, it would seem C177 was shorted.
Removed C177 and the cap is shorted.
The short across the other caps and the M8R340 has gone.
Also on the reverse side, VD5 showed as a short, but also now gone.

But what to replace it with? Its tied to the 12v rail. 0.1uf???

Dare I try it without this cap attached?

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

it is possible that one of these caps are responsible for the short circuit.

+10

[dick_barton]

Re: Hisense H55A6500UK backlight, sound but no display

Short across caps C238, C239, C177 and C176.

It is possible that one of these caps are responsible for the short circuit.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

yh done that, no difference!

[neilc6]

Re: Hisense H55A6500UK backlight, sound but no display

Power up the tv with the tcon to panel ribbons connected one side at a time to confirm you dont have a panel fault.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

Yh, I think buying a replacement T-con might be the best way to go!

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

That looks like a match, not sure on the postage, it just gave the rates to the U.S. when I clicked it: https://www.ebay.co.uk/itm/LVDS-TCON...EAAOSwgZ5cXu1e

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

M8R340 or MBR340, top right. DMM on diode setting get a reading of 120 one way only.
On the pcb pads get a short.
Sorry, picture upside down.

T-con disconnected from main and panel.

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

Are those shorts there with nothing connected to tcon?

[dick_barton]

Re: Hisense H55A6500UK backlight, sound but no display

Is the MR340 the correct number?
https://tinyurl.com/y788q8ep and it appears to be a mosfet
Where is it on the tcon? top or bottom?

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

Yh 12v on both sides of fuse and 1.8v on vcc1.8 and 1.2v on FRC_1.2V1.

Appears to be a short across VD8 - MR340, even with one side lifted the short exists between the pads, not the diode.
Short across caps C238, C239, C177 and C176.

[nomoresonys]

Re: Hisense H55A6500UK backlight, sound but no display

See if there's voltage on each side of tcon fuse, pos. probe on each side, neg. probe on chassis ground.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

Yh, the backlights are definately on and bright.

Disconnecting the T-con ribbons to the panel boards one at a time makes no difference, still no picture/menu.

[dick_barton]

Re: Hisense H55A6500UK backlight, sound but no display

The backlight voltage appears low as per what's written on the psu.
Can you clearly see the backlights are up nice and bright from the back of the panel?

I have seen that you say the backlights and sound working but no picture.

[notallbad]

Re: Hisense H55A6500UK backlight, sound but no display

Theres 18v on VAmp on XP805 connector and 125v for the backlights on connector XP701.