Philips 65PUS6503/12 with black screen

[Zaprodk]

I got a Philips 65PUS6503/12 with black screen. Mainboard boots up (i checked u.serv debug connector) and software seems to be good. Reacts to the remote etc.
Backlight is on and is bouncing up and down a bit during boot so that seems normal.
LCD panel is black, no image whatsoever.

I checked fuse on TCON, good. 12V supply gets to the panel.
Voltages on TCON:
U_H, U_L L_L VONE VCS1 VRD VCST HAVDD AVDD all practically 0V.

I ordered an identical TCON from a TV with a broken screen. This doesn't work as well. The TV with broken screen was so broken that absolutely no image could be seen, so i'm afraid that this TV was scrapped from the same problem and then the owner smashed it. idk. No returns on the TCON so i'm hosed. At least i have two TCON's that does the EXACT same thing here.

It seems like RT6929 is responsible for 1.8V and 3.3V (which is there!), 8.5V (which is missing), 17V (also missing) whereas the RT6936 i'm not sure what voltages it's supposed to make - the VH and VL i guess?

There's a testpoint from the main TCON thip (Samsung VTU61B2) called DCDC_EN that goes to the RT6936 and it only goes high (3.3V) when both flex cables is connected to the panel. No change in voltages, panel connected or not.

Any ideas what to try next?



Thanks!

[Diah]

Re: Philips 65PUS6503/12 with black screen

first test the panel by disconnect one ribbon at time... and if there U ribbon on the panel edge boards do the same each at time.. to terminate panel didn't damaged.

then the second suspect for this TV chassis "TPM186E" the "Saphi" firmware. many time found issue it cut GPU signal. to do this need install firmware with .pkg format.
here TPM186E_018.004.223.001 (Date published: 2019-11-05) upgrade_package.pkg format.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

As i mentioned i tried unplugging the ribbons for the panel, one at a time. Nothing changes. If both ribbons are not attached the DC/DC won't be enabled. I guess the TCON looks for the EEPROM on the panel boards.

There is a U-shaped ribbon as well that i didn't touch. I will have a try disconnecting that.

I don't think it's a firmware issue, but i will try a reflash anyway. It can't hurt to try.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

I tried downloading the upgrade_package.pkg and flash it onto the TV - twice even, no dice.
I tried unplugging the u-shaped flex cables on both sides. I can confirm that if even one of them is unplugged the DCDC_EN signal is not asserted from the main TCON chip, so it wouldn't be able to generate a picture. Apparently it checks that all H/V drivers are present before trying to power up.

I guess next thing is to hook up the scope to the LVDS lines and see if there is any hint of video being sent to the TCON at all.

I don't know the default function of the TCON - what would it do if it's supplied with only power - no I2C or LVDS data. Will it normally generate the voltages for the panel or does it wait until there is valid data sent to it?

// Per.

[Diah]

Re: Philips 65PUS6503/12 with black screen

did you feed it with HDMI signal to confirm you have sound ?

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

did you feed it with HDMI signal to confirm you have sound ?

No. I bought this TV as being defective so i've never tried connecting anything to it. I will try that next.

// Per.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

I tried plugging in a HDMI cable with source playing but i couldn't get anything to play. The speakers are silent. It's really hard to navigate it to the HDMI input without seeing what's happening.

I dumped the bootlog to some files here:
https://www.dropbox.com/sh/b5396s3d0...cVJH8s3fa?dl=0

// Per.

[Diah]

Re: Philips 65PUS6503/12 with black screen

when you dumped the boot log, did you forget your usb remain inserted ?

smart remote.apk to work on any android mobile with IR sender. under philips remote easily to switch the input to the desired port No.

you need to approve the sound before you do any things ells.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

The USB stick was removed once the firmware was flashed. No USB stick was inserted on any of these logfiles.

I don't have a remote with IR sender so that's out of the question.

I managed to set up a hotspot and let the TV connect. With the Philips remote app from the app store i was able to connect. The issue is that none of Philips' remotes have a button that send an absolute "External/HDMI" so the only thing i can do is press the "Sources" and it will bring up OSD and i can select with arrow keys. As in working blind.

So let's say i have no sound, this tells us that it's the mainboard that's faulty ... i sure hope it's not. Not worth replacing that.

// Per.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

I connected up a Chromecast on HDMI2 and tried playing around with the "Sources", arrow keys and enter/OK on the remote. After a minute i actually got OSD on the display for a few seconds and it disappeared again. When i select sources/Netflix etc. the backlight changes brightness. This must indicate that the GPU is running since it's adjusting backlight for the information displayed.

So this tells me that:
TCON is working - we have some other weird periodic error. I couldn't recreate seeing the OSD again unfortunately.

// Per.

[Diah]

Re: Philips 65PUS6503/12 with black screen

when you did flashing firmware which sign you can tell it flashed... did the tv reboot ?

same the apk i mentioned for you there are 2 option after you choice brand remote if you
want via IR or net work.

BTW you have ARC HIDMI on the TV. this will sync the port automatically if you connect it to ARC source.

all of us we hope the easy things... but testing need to be reasonable and one by one.. not as your way went to buy t-CON

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

It printed a lot of dots in the debug interface while reading from USB to RAM and then started to flash in hex 40000 blocks. Took a couple of minutes. After that it rebooted.

I'll try the app you mentioned.

[Diah]

Re: Philips 65PUS6503/12 with black screen

It printed a lot of dots in the debug interface while reading from USB to RAM and then started to flash in hex 40000 blocks. Took a couple of minutes. After that it rebooted.

I'll try the app you mentioned.

it did flashed...if you failed to have sound.. you need to consider on BGA issue at he MT chip

[Maalobs]

Re: Philips 65PUS6503/12 with black screen

The coldboot.txt log shows a fully completed boot-up sequence.
I inspected all the lines that mention "error", "warning" and "fail", I found that there is a lot of them but I couldn't identify anything relevant.
The log is unfortunately very noisy, it has lots of errors because of generic configuration that's irrelevant in this system, and just plain syntax errors on Linux commands.
I saw nothing that pointed to hardware errors, and the system clearly doesn't fall into protection mode.

In the turnon.txt log, if you search for "sam_mode_errors", you'll find the Error Buffer which appears to be empty (000 000 000 000 000), so nothing has been registered there.

The service manual is available to download from this page:
https://www.electronica-pt.com/esque...ileinfo/70261/

Maybe it's a red herring, but if it's easy to try, then why not see if you can force the system to tell you any helpful diagnostic information.
It says in section 5.2.3 that you have to be in Customer Service Mode to get layer-2 error codes from the blinking LED.
And to enter CSM, it says in section 4.4 that you have to enter the code 123654 from the remote control.
My experience with these codes is that you have to be in the Home menu for the code to trigger (you're working blind so wait long enough for the system to start properly, then press the Home button once and wait a second, then enter the code).
Maybe in this way you can force the system to show you an error code that you can look up in the table in section 5.2.3?

After section 5.3 there are a few flowcharts for troubleshooting, have you followed them?

Also, the backlight bouncing up and down at boot, that doesn't sound normal to me.
My 6000-series doesn't do that, nor does another 6000-series TV that I have seen.
It sounds rather like a series of boot attempts after the first ones have failed, but then again, your bootlog shows no indication of such events.

As for IR remote control; when I fixed a friend's TV (he only had a Bluetooth remote control), I went to a local shop and bought a generic Philips RC, and after I was done with the repair I returned the RC to the shop and said it was the TV that was broken and not the RC. Naughty me!

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

Well no one will believe me now, but after seeing that OSD image for a short while i sat for a long time, pressing source/ok and the TV clearly reacted. One of a sudden i got image again, and it stayed on!

After getting image it became clear that the previous owner had disabled the speakers, so that's why it was silent.

I did a factory reset and it pulled an even newer firmware down from Philips' website which it flashed.

The TV seems to be working properly, but i really don't like it working out of nowhere - this could correspond with BGA issue - i would rather not reball the BGA if i don't need to.
Or could this be software corruption that "fixed" itself after the reflash? I don't really believe it ...

// Per.

[Diah]

Re: Philips 65PUS6503/12 with black screen

Or could this be software corruption that "fixed" itself after the reflash? I don't really believe it ...

// Per.

my post #2 , you need to believe its firmware..the most stable firmware with out any issue the one i linked to you.. so would be good if you stay at it and block the update,

since you found the speaker was out , then no BGA.. i thought only on BGA because no sound.. and its not normal some one make the sound goes out via other source.

enjoy.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

Oh i didn'get the point about the firmware you linked was more stable. I will downgrade it again then.

// Per.

[Diah]

Re: Philips 65PUS6503/12 with black screen

Oh i didn'get the point about the firmware you linked was more stable. I will downgrade it again then.

// Per.

if you are going to downgrade. dont forget to make hard reset from service menu. so you will get clean system.

[nomoresonys]

Re: Philips 65PUS6503/12 with black screen

I wouldn't tamper with success, if it's not broke at this point I would just disable/block auto updates as suggested.

[Zaprodk]

Re: Philips 65PUS6503/12 with black screen

I wouldn't tamper with success, if it's not broke at this point I would just disable/block auto updates as suggested.

But it already upgrade itself to a "bad" software version, so why not downgrade to the good one again?

// Per.