Hisense 55'' Issues Mainboard or Power Supply?

[dabushar]

Hi Guys, i have a tv i bought a mainboard for (a hisense 55H8E) because it just stopped working. When i replaced with the new motherboard. The TV comes on displays the logo and starts up fine.

When i load or connect an input or play a youtbe video the backlight disappears but the audio and video remain. Anyone Experienced such? I have attached some pics of the old board the new board the power supply and the model.

If anyone can assist id be grateful.

[neilc6]

Any issue with the backlight is usually the LEDs failing or intermittent. You can try turning down the backlight level and see if they stay on longer. Running at 100% is what causes them to fail.

[Davi.p]

In the options menu try to disable something like "dynamic dimming" or similar, then retry with your videos... but still a leds problem remain..

[Diah]

Originally Posted by dabushar

Hi Guys, i have a tv i bought a mainboard for (a hisense 55H8E) because it just stopped working. When i replaced with the new motherboard. The TV comes on displays the logo and starts up fine.

When i load or connect an input or play a youtbe video the backlight disappears but the audio and video remain. Anyone Experienced such? I have attached some pics of the old board the new board the power supply and the model.

If anyone can assist id be grateful.

this had nothings to do with backlight issue.... hisense had option only audio.. to cut off BL. and widwine key for youtube content.. so..
yours replacement boards belong to different model.. size.. need to write firmware again by downgrade and then upgrade to register yours screen and T-CON. or try first with service menu option ( Clear Flash )

its so easy from the photo you can see the replacement boards had double ram.

[dabushar]

Originally Posted by Diah

this had nothings to do with backlight issue.... hisense had option only audio.. to cut off BL. and widwine key for youtube content.. so..
yours replacement boards belong to different model.. size.. need to write firmware again by downgrade and then upgrade to register yours screen and T-CON. or try first with service menu option ( Clear Flash )

its so easy from the photo you can see the replacement boards had double ram.

Thanks @Diah, The replacement board is the exact same but a diffrent region, the board is from the US. The Original is from Africa/MiddleEast. SO i think therein lies the problem. I think the replacement board is draawing to much current from the power supply and since the inverter cant handle it, it drains the mosfets below thus shutting off the backlight.

I was looking at the power supply for the US Hisense and its different. I think thats why its not working as it should. I have attached it.

My Question now is: Can i lift the IC's from the new board and change the ones i have circled on the new board. My guess is the TCON is the one that died and since its on the mainboard the whole board will not work.

If i transplant the IC's, Would the old board work? Or is the something else that should be replaced too?

Thank you

[Davi.p]

The top one is an audio.amplifier, the other ones can't be focused well with so an unclear photograph. the theory of the different drawn of power supply in mainboards is not realistic for me, the boards differences are very little in electrical level, i think and i'm convinced, you have a bad led intermittent. It is not easy.to diagnose this way but the only way like i did is to let the tv run at the lowest level backlight and wait when it no more light up, then.test every led.

[dabushar]

Originally Posted by Davi.p

The top one is an audio.amplifier, the other ones can't be focused well with so an unclear photograph. the theory of the different drawn of power supply in mainboards is not realistic for me, the boards differences are very little in electrical level, i think and i'm convinced, you have a bad led intermittent. It is not easy.to diagnose this way but the only way like i did is to let the tv run at the lowest level backlight and wait when it no more light up, then.test every led.

With the Replacement Board the TV starts very well, Backlight only disappears when you try any load (hdmi,aerial,youtube) When you restart the TV It starts up fine. Sorry about the bad photos. What i know about the leds is one is bad they all dont light up.

[Davi.p]

If the video input requests more light since it's a dynamic dimming maybe, then an half shorted led goes short circ. Check for the PSU connector signals to force the bl-on whitout a mainboard.

[Diah]

Originally Posted by dabushar

Thanks @Diah, The replacement board is the exact same but a ......If i transplant the IC's, Would the old board work? Or is the something else that should be replaced too?

Thank you

Short answer NO. !!! are you going to develop Main boards !!
you have now just issue with soc I2C address which its designed & a signed by firmware.. so..

1-before we lost in BL subject.. you need to tell me whats wrong / Fault you have with yours original main boards..
2- with out any source ..log in your service menu and upload photo on pages:
A-Design - MAINCHIP SSC
B-Design- DRC & PAGAIN

3- check on Factory page all Key written and marked with OK

[Diah]

Originally Posted by dabushar

Thanks @Diah, The replacement board is the exact same but a diffrent region,
Thank you

NO. different NAND / RAM = different soc I2C at firmware.

[dabushar]

Originally Posted by Diah

Short answer NO. !!! are you going to develop Main boards !!
you have now just issue with soc I2C address which its designed & a signed by firmware.. so..

1-before we lost in BL subject.. you need to tell me whats wrong / Fault you have with yours original main boards..
2- with out any source ..log in your service menu and upload photo on pages:
A-Design - MAINCHIP SSC
B-Design- DRC & PAGAIN

3- check on Factory page all Key written and marked with OK

I removed the heatsinks and took a better photo. I have shared the photo below..

Original - https://ibb.co/C6YdvVk
Replacement - https://ibb.co/NSFJJCX

[Davi.p]

No different nand / ram... only cpu heatsink mounted in different way that covers chips.

[dabushar]

Originally Posted by Davi.p

No different nand / ram... only cpu heatsink mounted in different way that covers chips.

What if i give the backlight a signal and another direct inverter so that when switched on the backlight comes on irregardless of the source on the power supply.?

[Davi.p]

I don't undrrstand, do what i have suggested earlier.. if you are not familiar post the silkscreened table of the pins on the power supply..

[Diah]

Originally Posted by dabushar

I removed the heatsinks and took a better photo. I have shared the photo below..

Originally Posted by Davi.p

No different nand / ram... only cpu heatsink mounted in different way that covers chips.

original set A6100 series replacement boards come from H8000 series.. hisense not so dumm to sell TV witj just heatsink flip up.... we are not judging by looking on beautiful woman with same eyes and lips... but the hearts (FW) are different. this why i asked to see her hearts value. LOL

[nomoresonys]

Save yourself from pulling all your hair out and just get the correct mainboard.

[dabushar]

Yes, I think i will just have to get the correct mainboard for the A6103.. I saw the power supply for the american version and it's totally different. So the structuring of the backlights is very different, so my power supply wouldn't suffice. Even if I add an external inverter, it still would have some issues, Thanks for the help. You guy's are awesome..

[Davi.p]

When you will spend extra money for a new board and you will see that is not enough? And with a test of few minutes you have the answer maybe.. testing the BL can be a very easy task.. i don't understand you.

[dabushar]

Originally Posted by Davi.p

When you will spend extra money for a new board and you will see that is not enough? And with a test of few minutes you have the answer maybe.. testing the BL can be a very easy task.. i don't understand you.

I already tested the backlight, i tested the board off the TV with other BL strips. Its shuts down.. I took photos of the TV working and loading content below
https://ibb.co/KzqLTrm
https://ibb.co/56Z3NtF
https://ibb.co/S72Zqw2
https://ibb.co/mR1fjmk
https://ibb.co/LtJrN8C
https://ibb.co/pJj1tHB

So problem is the different mainboard... Below is its power supply..
https://www.ebay.com/itm/Hisense-Pow...-/223495628051

as you can see the power supply has an extra board on top for connection to backlight board.. Only found this recently

[Davi.p]

ok this is a good test, so with external strips its shuts off after how much time or in which condition?