Sasmung la40m81bd - Recapped

[Amraks]

Re: Sasmung la40m81bd - Recapped

Chip I flashed is IC1803 is a 24C256
No flashed firmware after the erase as the tv writes to the chip when blank chip is detected
Can get into service menu but its very hard to navigate being the picture is the way it is.

[nomoresonys]

Re: Sasmung la40m81bd - Recapped

That chip costs 1 dollar, I'd replace it with a new one, that will at least confirm or eliminate it as a suspect.

[Amraks]

Re: Sasmung la40m81bd - Recapped

yeah I have ordered 5 of them, seems weird that I have the off/on clicking fault now after erasing that chip.
chip sectors could be bad and its writing on the corrupt chip sectors creating incorrect settings for panel and the watchdog is now kicking in as it should be.

[Amraks]

Re: Sasmung la40m81bd - Recapped

Tried a new chip not fixing any fault

2 of these caps under the metal shield

44080
82
6FA

One reads higher than the other of the same value on my esr meter
.16ohms
.04ohms

Could this be my problem?

[Amraks]

Re: Sasmung la40m81bd - Recapped

Also found some of these caps on the mainboard are reading funny

100
16J
Which look to be the JC series in Samwha
some are reading
1.0ohms
.90ohms
.09ohms

there is a few of these caps all over the board it seems like the lowest readings are the rarest ones

[Davi.p]

Re: Sasmung la40m81bd - Recapped

Hi, i don't like the suggestions done here in this thread..
the video shows evidently a corruption in firmware data, the part on the flash chip or the data copied into the RAM, so best way to do for me is to begin with cap replacing, for the 3,3v that feeds the Flash 29AL032 are C1110,C1177, for the DDR 2,5v is the C1149, since before or after but very often fails also C1165,C1167 change also them. I don't know what it is HYB25D256 chip, seems another flash chip, anyway if the cap replacement doesn't work then a reflashing of the firmware (NOT THE EEPROM!!) is suitable but the file is unavailable.

[Amraks]

Re: Sasmung la40m81bd - Recapped

Ok I replaced them caps you have mentioned also took the liberty of replacing C2267 and C1140
this has made a bit of difference in the picture I can recognise some text in menus but it seems a little flashy still.

[Amraks]

Re: Sasmung la40m81bd - Recapped

Here is a new video
I have bought up some menus also I never switched it off, it did this by itself.
https://www.youtube.com/watch?v=WgGf9TVDFj4

[Davi.p]

Re: Sasmung la40m81bd - Recapped

ok maybe some caps are still bad on the mainboard, or there's a problem in the video RAM, for the shutting off then on surely the job done on eeprom is not a good thing, it must be placed back the original eeprom with original content, or right to try, delete the actual eeprom maybe with the short on pins 5,6 during the mains plug connection (stay so for 10 seconds), then shut off then on.. another common fault in theese boards is the soldering if i remember on the ST CPU.. if i'm right the ST governs the DTV (terrest. digit. tv). Try to warm it up for 30 secs at high temp, at least 300 °C, then try the tv, if its better then do a reflow.

[Amraks]

Re: Sasmung la40m81bd - Recapped

Not sure what's going on with that could still be processing video.
Try again soon.

[Davi.p]

Re: Sasmung la40m81bd - Recapped

What do you mean?? Try what? I think the most probable culprit is the ST chip and its solderings, the things are strictly related, PSU and Mainb. caps generate high ripple that causes the ST chip to get too hot then solder balls detaches itself.

[Amraks]

Re: Sasmung la40m81bd - Recapped

C2267 and C1140 there is a short to ground on these two caps hmmmm

[Amraks]

Re: Sasmung la40m81bd - Recapped

its weird its only doing it after board has been on

[Davi.p]

Re: Sasmung la40m81bd - Recapped

How do you measure this? first you have to measure in volt to be sure to not damage the tester, then you can measure in ohm with caution..

[nomoresonys]

Re: Sasmung la40m81bd - Recapped

ok maybe some caps are still bad on the mainboard, or there's a problem in the video RAM, for the shutting off then on surely the job done on eeprom is not a good thing, it must be placed back the original eeprom with original content, or right to try, delete the actual eeprom maybe with the short on pins 5,6 during the mains plug connection (stay so for 10 seconds), then shut off then on.. another common fault in theese boards is the soldering if i remember on the ST CPU.. if i'm right the ST governs the DTV (terrest. digit. tv). Try to warm it up for 30 secs at high temp, at least 300 °C, then try the tv, if its better then do a reflow.

WRONG, when these eeproms are replaced they use new blank chips.

[Davi.p]

Re: Sasmung la40m81bd - Recapped

I reorder things, i remembered bad, then the chip erasing it's been already done, but what it's been done after? 'Cause the tv usually needs an initialisazion, it's been made it ('cause before cap replacing the characters of the OSD was no readable)? So the chip has not been changed and the original content is lost.. now that characters are visible a little a service menu reset must be made, with TV initialisation after..

[Amraks]

Re: Sasmung la40m81bd - Recapped

I have gave up on this tv only solution would be a mainboard.

[Davi.p]

Re: Sasmung la40m81bd - Recapped

ok i've learned a thing, never put much effort in a forum!...

[Dannyx]

Re: Sasmung la40m81bd - Recapped

Your effort is much appreciated, as it can be useful to others out there

[vinceroger69]

Re: Sasmung la40m81bd - Recapped

I have gave up on this tv only solution would be a mainboard.

maybe search you local free adds etc or ebay for a cracked screen set if you cant find a replacement mainboard cheap enough.