eeprom unbricking for C8790 models

[juusso]

Looks really good quality but i still can`t see what is IC7806, IC5091 and IC4011.
Those whit Z... aren`t our object. Look for AT, ATM, or just digits on the chip (24512 or so)

[bossi]

I have updated my posting and sharing of the pics and now it should be possible to read the
chips..
I see Z1021HAI | ZA0E37
Z1031AI | ZA0H38

but not the ZAL or similar..

and I have added snapshots made with "iphone" wich shows the Label of the chips....

[juusso]

IC4011 and IC4002 are blury and label still unreadable. sorry
can you take photos of them once again?

And check please is here any chip in backside of mainboard. you have to completely dissasemble mainboard for that goal.

[bossi]

I hope I have it now ?..
The Two EEPROM Chips on the Backside of the Mainboard are identified as well....
What to do now ?
Same like I found in the Wiki page ?..
PIN 5+6 bridged and 20 Secs Power on the TV ?

[juusso]

on the mainboard are at least two eeprom usually. one for SoC (we need to reset) and one for micom (we don't need to touch or touching it we don't get any expected effect). So you should check which is closer to the SoC chip on the front side and then yes, make short on 5-6 pins while boot TV. I probably would bet for https://www.dropbox.com/sh/hwqfncfymlut ... C00183.JPG but can't see proper location of chip and yellow fonts are also bad readable (try to don`t use flashlight). If this chip is wrong and it wont repair your TV, do the same on another, IC8505.

btw, better quality photo of whole backside is welcome...

[bossi]

i have shorten both ship.. , but loop still there

[juusso]

Can you make ExLink cable and check for the output? Sure we will get the debug output if you changed rs232 to debug in service menu before to brick. If not, then this not gives any info.

Don`t give up. Repeat procedure few times, optional you could shorten pins 5+8 (instead of 5+6). Be sure you unplug the power cord first time you power TV with shortened pins.

I wonder what does it mean "boot loop", is TV continuously rebooting? Is LCD black or you can see anything there?
Boot loop is usually happen not because of service menu settings, something should be done in filesystem (is your TV rooted?) or might did you do firmware upgrade recently?
How long does it take from power on until TV goes to reboot?The more info you give ten better. As you`ve asked for eeprom reset, we went this way, but can be the problem somewhere else?

[bossi]

What I do: (note: the TV isn't rooted or no other changes to the Service Menu like the "type"
1. TV back from FW 3015 to 0000 to have the ability to install 3005 again.. (The setup procedure after set back to 0000 are not closed) TV restarted into Service.
2. Back in service menu I must have change the "Type" setting of model type (told my wife.. here not to change..she has questions about other things and so..
when I come back to the TV.. I must have change the type.. while I have the Remote control in my hand.. when I talk with wife..
3. TV switched off.
4. After switching on... Boot sound comes.. picture black... nothing to see (nor gosthed letters.. or so)

addionally the TV must have broadcasted into my network.. The NAS Server gets maybe a UDP Signal.. and MAC-Address and Model type of the TV
were stored there.. The NAS server was installed after TV got's bricked.. so I'm sure .. (TV type actually C6820.. wich isn't compatible type for this TV.. that's really sure.

When TV are a longer time without Power Plug in.. It sometimes starts with a sound... and then noting.. only black screen...
and other situation.. TV starts with no sound and nothing happend.. Remote Control signal blinks... everytime.. but with no reaction... and so..

I changed this posting for better understanding what's goin on there... and also I'm not sure if bridging the PIN 5+6 on eeprom gives a better result, and TV goes back to his needed settings or so...

I also didn't know if it's possible to set back by a service technician... If possible.. I will invest it...I buy this TV for 1.600 ?.. and it's not so cheap.. to buy a new similar one...

[juusso]

I think one of backside eeproms are proper, just possible reasons of fail:
- procedure typos (bad contact of pins/no contact, bad pins chosen - 1st pin is always marked with < sign and so on)
- even wrong chip is chosen. I doubt about this, because there is no other eeprom on your mainboard at all.
- eeprom reset doesn`t solve your problem. This is almost same as if you chose "factory reset" in service menu.

0000 firmware is not for normal operation, you can`t watch TV, if possible feed TV with T-VALDEUC 3005 (tv must accept upgrade?). Sure if no loop, because situation can be really dangerous if reboot comes during the upgrade process.

- now i understood you`re able to get in to service menu if no reboot come? First what come to my mind, is - you have to disable watchdog (config-sub option-watchdog off). And maybe you can change model setting as well. Weird, i have to ask questions one by one to make the picture of problem, like physician..

[bossi]

you're completely right.... do you think it's possible to update do T-VALDEUC3005 without see something ?
I also think the machine tries to setup for the normal TV use.. Channel Settings etc..

but most of the time when I plug power in.. the machine sounds the boot... and then clicking and.. again.. sounds the boot.. and so on..
but.. when i found a right moment... it's possible to switch off with remote control.. one time i think i've entered the service mode.. but..
cant see somehting... ...

to create a exlink cable isn't possible for me.... when this will help..
I must now close the TV.. in the later afternoon there comes a little baby.. and eats the screws.. maybe...