Bricked UE46B7020 ??

[james2810]

Hi everyone!

Hope someone can help me.

What happened:
[*] Actually I installed SamyGo already short after getting the TV in 2009. Mainly because of the aspect ratio fix
[*] Last sunday I tried to install the DTS-patch. Which actually worked well when started as a widget
[*] Then I tried to install it as a autoload-module with GDB-trick.
[*] I placed it in SamyGo.sh to start. But it seems that I placed it on the wrong place and doesn't work.
[*] After the next reboot I got stuck in a bootloop where it still is.
[*] Unfortuantely I didn't

The bootloop looks as following
[*] When plugin the screen clicks as usual
[*] Then the light reacting on remote control commands blinks then times
[*] The backlight turns on
[*] After some time it reboots and does this for a whil
[*] There is no reaction on remote control commands (poweroff, service menu, ....)
[*] There is absolutely no output on the screen

What I tried until now
[*] Tried with a USB-stick and usb.sh to rename / remove the SamyGo.sh-Script so that GDB is not started anymore
[*] But unfortunately it seems that I placed the GDB-trick before the usb.sh-if-condition. Therefore this doesn't work

[*] I build myself an Ex-link cable which seems to work when testing with a Voltmeter.
[*] Used putty with the written parameters (115200/8/1/N/N)
[*] When connecting to my notebook and screen I get absolut no output (except when the 3.5mm plug is not correctly inserted. Than I get some strange characters on the screen).

[*] Tried to reset the EEPROM to be able to activate the Debug for RS232 (btw. is there no output on RS232 because I didn't turn debug on?? So absolutely no output when on UART??)
[*] Therefore opened the TV and found it (layout seems to be the very same as written in Wiki for B6000).
[*] Also found a button which seems to interrupt the power-supply (is this the magic button?) When holding for a long time and releasing -> no change
[*] Connected SDA+VCC and also tried with SDA+GND.
[*] No success

No I am done with all my knowledge and information I found on this great page.

Hope that someone can give me a hint what I missed or what I could have done wrong.

Thanks in adavance.

KR,

James

[juusso]

to get tv back you need:
1) properly working exlink cable.
2) debug in service menu (oops, you did eeprom reset = you set it to uart even if it was on debug, but it wasn`t)
3) proper u-boot partition, which was deleted by postfeb firmware upgrade.

1)So exlink cable is well explaned and very very simple schematic, i believe you didn`t mix 3 wires each together...
2)main problem with debug. I doubt if it was/is ON. Even if you had it on initially, you have lost it by doing short circuit on eeprom. Bad experience w/o knowing the nature of the brick. No need to try each instruction found on wiki, things may be worse then...
Problem is, i guess, that your exeDSP crashes. At this point you won`t repair your TV via exlink. Console is locked and you have to input "debug" to get it unlocked. BUT unlock function resides inside exeDSP which crashes w/o letting you to unlock it and use linux shell.
3) Only the hope is your u-boot partition wasn`t deleted. If you do not know, post your firmware version.

[james2810]

Hi juuso!

Thanks for your quick reply

1.) Yes, I expect that the Exlink cable works well
2.) I tried to connect to the TV via Exlink before EEPROM reset. Actually no change (means no output before and after). But I also don't know if EEPROM reset worked (actually it is mentioned that then RS232 should be in Debug again)
3.) How can I find out which firmware version I have?? I flashed it last time some 6 years ago ... but most probably it is T-CHU7DEUC as this is what I still find ond my PC (T-CHU7DEUC 3000.G, SWU_T-CHU7DEUC_003000_I02_ES000DS000_091111).

[juusso]

Your firmware seem ok. No idea if u-boot is still here, but let believe it is. I think the only way to get debug on is to dump (micom?) and SoC eeprom and try to find which value is responsible about debug -> ON switch. To understand better what am i talking about, read topics (yes, only D and C series...).
viewtopic.php?p=38958
viewtopic.php?t=7117
B series was not investigated yet. Hope here no much differences...
You can unsolder eeproms, make dumps with programmer (like wilem programmer etc) or use arduino approach described there. Do your own investigation.

OR buy new/used mainboard, which i believe is hard to find nowadays.

[james2810]

Hummm .. this doesn't sound too promising ...
Is there no other chance to bring this guy back to life??

[juusso]

Any "magic button" on the mainboard which could switch debug to on? it may be not soldered in... some b series models have it and it may help you.

[james2810]

As I wrote there is a button .. but it seems just to be a reset button ..
How could I find it if it is not soldered??

[juusso]

Ah, right, on b7 series it does just reset... then no other way except described above. Imho.

[james2810]

shit .... any idea where to find a mainboard?? googling also doesn't look to promising ..

[juusso]

Check for part number on your mainboard (e.g. BN94-02706U) and search on the internet. I suggest you to check local samsung service first, maybe they can get it for you. Search for not only mainboard for exact your model, mainboards for screen 32-55inc are compatible. Also B7000 is ok for you, or any of B7 series. For example part number of B7090, this could be the case for you as well BN41-01190C / BN94-02764Q.

I`m not very sure, but mainboard from CI+ model has same connectors as yours and should fit and wok well (BN94-02764J). Etc.