HISENSE H55B7500UK has backlight no picture

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

you first start trying with N1 group.... if no result bring back the cable as original and try N2

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

the reading not normal.. because the amount of LEDs at each Group are same amount.

i think now this happen.. at time the TV on. there are error at BL... main boards didn't complete the booting normally... but after at start up script of BL ON order the BL turn on... but its little late maybe in 1-2 second....

i never faced such issue .. its really interesting to discover the reason and terminated it..

so i will suggest the following to try... as you are not expert at electronic,,, so i will make it easy DIY
take any Normal house Flammable Lamp... ( like table lamp ..etc ) doesn't matter the watts.. but not less 20 ..... each group cutting the N of them and put the lamp in between... to act as as Resistances .. ( it will dummy the power boards as the group working fine )... if our thought correct... you will see at least Hisense start up Logo on screen

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

When i plug into wall socket
1p 1n 15-11v
2p 2n 34-29v
When i turn on the tv
1p 1n 103v
2p 2n 104v

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

do the measurement method 2... P1 N1 .... and P2 N2 at plug in wall socket.... record the high and low

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

High vol 1p and 2p 144-130v in 10s when i plug into wall socket.
Low vol 1p and 2p 126.8v when turn on the tv

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

Do you mean 2 groups of led backlight?

sure,,, there are 2 way to measure..
do first put yours DM on 250V DC. black probe on TV chassis.. and the Red Probe of the Red wire of each Group... turn on and notice the high V and the low at start up .. write yours result here

second method of measurements... DM at same Level DC ... each group black on black as well the Red on Red.... then turn on

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

Do you mean 2 groups of led backlight?

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

i would suggest start from Zero to trouble shooting... start with LED BL... yes you can see light... but you have 2 Group need to measure the currents of both and compare them

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

we don't know the history of this TV.. actually when you do testing the T-CON and panel standalone should display color pattern ,

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

of course.. its still working link.... go to 55 and then B7500 download all version.. to have them as archive for you

Do i need to check voltage on panel edge buffer boards?

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

I found this in other topic, can i use it

of course.. its still working link.... go to 55 and then B7500 download all version.. to have them as archive for you

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

To all owner of Hisense here are the customer service Firmware archive
Password : Hisense1234

enjoy

I found this in other topic, can i use it

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

I used heatgun to heat cpu in 2 mins and nothing happen.
Can u give me the firmware to try flashing

call hisense and asking for it... they will give you link

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

I used heatgun to heat cpu in 2 mins and nothing happen.
Can u give me the firmware to try flashing

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

go hard play on MB.. check any low volts you have for emmc or DDR or cpu.... if all fine...take out the heat sink.... and do what you can to heating the cpu to touch again in it place if you did trying flashing the firmware.... good luck

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

i saw your movie.... try to disconnect the WIFI BT module and turn on.. if the same issue you have issue at MB.. emmc dead or Firmware ... try to write firmware again via USB... am sure 5V at USB you have because T-CON 12 V you have measured before... if this didn't help then replace MB or packing it LOL if u have BGA station then refleo main CPU

Yes, i m having 5v on usb port.
I tried to disconnect the WIFI BT module at the first but it didn t help

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

i saw your movie.... try to disconnect the WIFI BT module and turn on.. if the same issue you have issue at MB.. emmc dead or Firmware ... try to write firmware again via USB... am sure 5V at USB you have because T-CON 12 V you have measured before... if this didn't help then replace MB or packing it LOL if u have BGA station then refleo main CPU

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

you don't have any u ribbon cable... did the tv after blinken stay at blue led on ???? if yes try feed it with HDMI signal from HDMI port with remark of CEC to check if there any sound

No led on after 6 times flashing@@
I already tried all 3 hdmi port and still didn't hear anything

[Diah]

Re: HISENSE H55B7500UK has backlight no picture

you don't have any u ribbon cable... did the tv after blinken stay at blue led on ???? if yes try feed it with HDMI signal from HDMI port with remark of CEC to check if there any sound

[snowangel27]

Re: HISENSE H55B7500UK has backlight no picture

take out the speaker... and reach the panel edge buffer boards see if the left and right had at the middle U ribbon cable... if yes disconnect it from one half and turn each time

Which one?