samsung le40s71b

[senndogg]

Re: samsung le40s71b

@scenic. i dont knwo whats inside this eeprom. soon i'll read this, but if it is corrupted that means i would have to download it somewhere and rewrite, right?
@randtek. yes i did. but has no affect. the t-con remains a possible fault for this tv. i suspect that the faulty t-con dont let the tv start properly.

[Scenic]

Re: samsung le40s71b

The problematic EEPROM stores all the user settings (volume, brightness, sound settings, channels, ...). If it gets corrupted, it causes all kinds of stuff to go wrong.

On one of the Samsung LCD TVs I've fixed, the faulty board powered up, but all the settings were just totally messed up, like contrast was set to 255 out of 100 max. and it restarted every ~15seconds on its own.

"Resetting" that EEPROM (deleting it's contents) makes the TV rewrite the default values to it. No need to program it manually.

If the EEPROM trick doesn't do anything, it's basically a gamble. Main suspects would be the mainboard (which can easily be replaced, even though it costs quite a bit) or the LCD panel itself, which would make the whole thing uneconomical to repair.

My guess would be the mainboard. It could be a faulty cache memory chip (usually a little SD-RAM chip close to the main CPU) on the mainboard causing this glitched up display, rather than the T-Con.

Judging by how the mainboard already has problems with staying on (like the previous Samsung LCD I fixed by replacing the mainbaord), I'd say the mainboard somehow got damaged (lightning via antenna cable? failed firmware update?!) and it causes the restarts and messed up display.

[senndogg]

Re: samsung le40s71b

The problematic EEPROM stores all the user settings (volume, brightness, sound settings, channels, ...). If it gets corrupted, it causes all kinds of stuff to go wrong.

On one of the Samsung LCD TVs I've fixed, the faulty board powered up, but all the settings were just totally messed up, like contrast was set to 255 out of 100 max. and it restarted every ~15seconds on its own.

"Resetting" that EEPROM (deleting it's contents) makes the TV rewrite the default values to it. No need to program it manually.

If the EEPROM trick doesn't do anything, it's basically a gamble. Main suspects would be the mainboard (which can easily be replaced, even though it costs quite a bit) or the LCD panel itself, which would make the whole thing uneconomical to repair.
My guess would be the mainboard. It could be a faulty cache memory chip (usually a little SD-RAM chip close to the main CPU) on the mainboard causing this glitched up display, rather than the T-Con.

Judging by how the mainboard already has problems with staying on (like the previous Samsung LCD I fixed by replacing the mainbaord), I'd say the mainboard somehow got damaged (lightning via antenna cable? failed firmware update?!) and it causes the restarts and messed up display.

thank you scenic, this might be the answer i was looking for!!!!!
the eeprom trick (i have done more then once these days) every time causes a different strange behaviour. for example yesterday the samsung jingle went off. now it just restarts in silence. i must find a board just for a try. there is a 80$ in ebay, but not worth for trying.
thank you once again scenic (rep+ from me) and i can consider this thread closed till i'll have a similar mainboard in my hands. cheers!