Difference between revisions of "UnBricking TV by EEPROM Reset"
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[[Image:C550_reset.jpg|200px|C550/530 reset. line!]]
Revision as of 19:22, 27 February 2012
This is Erdem. As I bricked my D series device by miss service menu setting, I search for solutions to recover it. After with help of Jusiz we unbricked device with the same way of C series TVs...
Here I wanted to try to let you know how the process is working.
Firstly, this hack doesn't work if you bricked you device by firmware flashing... This hacks just removes service menu settings and let you give another chance to fix settings...
Also you needed to find correct values for your TV after resetting NVRAM like Model / Type / Tuner / Font Color and others. It's better to have screen shots of your service menu. You can also ask help from our forums.
EEPROM is a short of electrically erasable programmable read only memory, which is actually a chip. In Samsung TVs, all service menu settings kept there. You can delete and reprogram this chips millions time. So they are fast and reliable...
Reseting NVRAM (EEPROM)
For resetting TV, settings, you needed to remove EEPROM device from TV. But it's not required. In electronic world, if you disable communication of the chip, it counts as removed. So we just needed to kill communication of EEPROM. EEPROM on Samsung TV's communicating via common i2c protocol. That protocol carries data via SDA line and send clocks via SCL line. In our situation, both blocking SCL or SDA will works. But I decide SDA.
To do this, all you have to do that feeding (connecting) GND (ground) or VCC (3.3v) to SDA line with little wire... That's all. Since this lines are HIGH (v3.3) in IDLE, its better to hold it via VCC. You can also hold this lines via GND too. But don't try to connect both GND and VCC. It will be short circuit and probably will damage your board.
Hold the connection about for 20 secondes with the TV powered. It just try to read (wrong) settings from EEPROM, since it cannot read anything (refer to the warning message bellow), just start with defaults. That is what we want. Than releasing SDA line and shutting TV off will update the settings on EEPROM with null values, that TV could boot with it. After all, you can enter service menu and change the required changes.
Where can I found that EEPROM chip ?
- Its located near CPU at C and D series. On top, it writes some numbers and letters starting with 24256 or 24512... Here I place some screen shots from D series bellow. In my TV, 24512 EEPROM chip used. You can get the 24512 Chip Datasheet here. In picture, white triangle shows the first pin.
C Series EEPROM Location
please fill up missing models. Thanks!