Sony KD-55X8505 not able to start

[PowerAmpFreak]

Originally Posted by Diah

you have BL_error on the sockt. if its goes high at boot then you need to be ready for the hard work BL LED

BL_ERROR show +2.4V at boot. The same with leds disconnected. But shouldn't it blink a led on the front ?

[Diah]

you need to take look from down side of the boards to see the OUT1+ & OUT2+ are share same source.. OUT1 (1-4)- are separated same to OUT2(1-4)-

and your caputre messurments of V high and low should be as following

each time you messure OUT1+ to OUT1 line 1- then line 2- till 4 same way to OUT2+ with its group
do in total you have 8 groups you need to messure each at boot to find one are different

so you need 8 time messure at boot

[PowerAmpFreak]

All 8 measurements gives a value of 1.2-1.5V only. CN6801 voltage is only 63V during boot and will not change. I guess this is too low to overcome all the series leds voltage drop.
By this I think also the BL diagnostic can't detect failure in BL since MB does not turn on the higher BL voltage...

EDIT: Tested each of the 8 led lines with constant voltage 90V and draw 40mA each so I guess the BL is OK

[William1967]

Try the recovery mode, If after the recovery mode the device starts up and works properly, immediately make a copy of the EMMC and load it into a new EMMC. If that does not work, the EMMC must be replaced and equipped with properly working software.
Have had dozens of these models all doing the same thing and all in need of a new EMMC, the part has reached an "END OF LIFE" status and therefore the bootloader can't start.

[PowerAmpFreak]

Originally Posted by William1967

Try the recovery mode, If after the recovery mode the device starts up and works properly, immediately make a copy of the EMMC and load it into a new EMMC. If that does not work, the EMMC must be replaced and equipped with properly working software.
Have had dozens of these models all doing the same thing and all in need of a new EMMC, the part has reached an "END OF LIFE" status and therefore the bootloader can't start.

Thanks for posting. How do I enter recovery mode?

The set won't even be in a normal standby state, nor reacting on any keys nor remote

Is there perhaps a jumper to short on the MB perhaps ?

[Diah]

unplug the wifi module socket on the IR reciever boards and trace the 3.3V

you can follow the 3.3V on MB (Page 136 service manual)

[William1967]

Originally Posted by PowerAmpFreak

Thanks for posting. How do I enter recovery mode?

The set won't even be in a normal standby state, nor reacting on any keys nor remote

Is there perhaps a jumper to short on the MB perhaps ?

Search the internet, there is a lot of info about "Sony tv recovery mode" for example here

[PowerAmpFreak]

Originally Posted by William1967

Search the internet, there is a lot of info about "Sony tv recovery mode" for example here

Yes, but the problem in this case is that recovery mode involves a remote sequence and since the set does not even recognize keys nor remote, it will be hard...

[dskall]

Have you watched any of Nick's TV Repair videos? He has a few on sony.

[PowerAmpFreak]

I am following the fault trace chart in the Sony service manual and many of the start-up failures does lead to -> Replace IC9017 which happens to be a PIC mcu P/N PIC16F527.
Anyone knows if this is programmed with firmware by the main mcu during start-up if the part is changed to a new one?
Or do I need to find the correct flash and pre-program the device?

[MICROTECHSERVICE]

sorry for late late reply as i do lot of these main emmc is at fault replace it should fix it

[nomoresonys]

@William1967 or MICROTECHSERVICE, do you get voltage on bl-error pin when emmc is the problem and can it come on with the android music but no display or backlights? or does that indicate a different problem?

[William1967]

Several problems can occur when the EMMC is faulty, the most common is no function or start up with only the Sony logo.

[nomoresonys]

ok, thanks.

[nomoresonys]

I see now, that's one of the most heinous acts of planned obsolescence I have seen, will never buy a new sony.

[nomoresonys]

my chip has density of 16GB and a storage capacity of 64GB, would it do any good as in last longer if I replaced it with 128 GB or would there be a problem?

[PowerAmpFreak]

In my case, as the OP, the set does not even try to start-up, either BL or any form of sign of life. All the voltages from PSU are OK.
@Microtechservice do you have the details for this set how to replace the EMMC ?