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UnBricking TV by EEPROM Reset

Posted: Sun Oct 12, 2014 1:11 am
by fredrock46
I'm not sure I'm doing this right but I'll try anyway. I came across an article here on SamyGo that explains the exact procedure that what I want to try on my TV.
It's titled UnBricking TV by EEPROM Reset.
The only problem now is that I see this forum is dedicated to Samsung TV's and mine is a Vizio. I believe the procedure would be the same but I don't know which two eeprom pins I should bridge to try it. This is a Vizio SV422XVT TV and when I plug it in the logo flashes orange/white but it won't come on. I can't find parts for it and I have tried everything else so this is probably the only chance I have left to get it to come on. I'll attach a picture of the main board. Maybe someone can tell from that which pins I want. Again, I know this is probably the wrong site for this but I can't find another. Thank you for any suggestions or site referrals.

http://wiki.samygo.tv/index.php5/UnBric ... PROM_Reset
It's in the section titled "Resetting NVRAM (EEPROM)".

Main board picture is here: http://www.shopjimmy.com/media/catalog/ ... 120150.jpg

Re: UnBricking TV by EEPROM Reset

Posted: Sun Oct 12, 2014 9:41 am
by juusso
Post labels of all 8-pin chips here. If you read forum, you know what you have to look at. Btw, check the other side of mainboard too.

Re: UnBricking TV by EEPROM Reset

Posted: Mon Oct 13, 2014 2:39 am
by fredrock46
I circled the 8 pin chips in red. The one closest to the VGA connector is U33 and has ATMLH952 printed on it.
The one I think likely to be the eeprom is circled with 3 red. It has 25P80V 7B248 PHL printed on it. It has two names on the board U68 and U75.
There is only one 8 pin on the other side of the board. U73 labeled L333G5201

I,m not quite sure what you meant by labeling them so I'l post this now and if you need more info let me know. Thanks for helping me with this.

Re: UnBricking TV by EEPROM Reset

Posted: Wed Oct 15, 2014 2:03 am
by fredrock46
I guess I didn't post the info you wanted. Can you tell what I should do?

Re: UnBricking TV by EEPROM Reset

Posted: Wed Oct 15, 2014 10:42 am
by juusso
fredrock46 wrote:I circled the 8 pin chips in red. The one closest to the VGA connector is U33 and has ATMLH952 printed on it.
No, it`s voltage regulator, don`t touch it.
There is only one 8 pin on the other side of the board. U73 labeled L333G5201
I don`t know what is this chip for, can`t find any references for it.
The one I think likely to be the eeprom is circled with 3 red. It has 25P80V 7B248 PHL printed on it. It has two names on the board U68 and U75.
I bet for this chip, more likely it is Micron IC, FLASH SERIAL 8MB, 25P80.
Manual and pinout: datasheet, page 7. I don`t know this type of memory, but i quess it should be enough to block data output from device. Maybe VCC(pin8) + Q(pin2) should be ok? Or VCC and C(pin6). Also very interesting what the HOLD is used for. According description it should block the chip:
The Hold (HOLD) signal is used to pause any serial communications with the device without deselecting the device.
During the Hold condition, the Serial Data Output (Q) is high impedance, and Serial Data Input (D) and Serial Clock (C) are Don?t Care.
To start the Hold condition, the device must be selected, with Chip Select (S) driven Low.
Decide by yourself. Don`t burn your TV :)