• Recovering the SPD EEPROM device of the 240-pin DDR2 SDRAM module with corrupted SPD content.

If the SPD firmware which is stored in the SPD EEPROM device has been corrupted in the process of flashing or was not correctly selected and flashed for the certain memory module the system may not boot due to failed memory module initialization at POST. The major question of users who have corrupted SPD data is Уcan the module be recovered?Ф. The situation is very critical indeed, but there is a good trick to be used for resolving such issues.

Although a solution is very simple, it needs much attention from the user. First, your system needs to be placed into the hibernate mode. Second, you have to isolate with a paper tape all non-SPD EEPROM related pins on the module from being used when it is in the DIMM slot. After that, during hibernate mode, the module has to be inserted into the DIMM slot and the system should be transitioned into the normal operating mode. If the SPD EEPROM with corrupted firmware is not detected by Thaiphoon Burner you have to try to perform a hot plugging procedure for the module with isolated pins after POST is finished. Despite the hot plug is not recommended since it may damage the module at all, this may give you the final chance to recover the data.

Now let's see what inputs are used to access the SPD EEPROM device.


In accordance with the figure above, the following table combines the pins to be specified for accessing the SPD EEPROM chip of the 240-pin DDR2 SDRAM Unbuffered/Registered module. These pins need to be not isolated on the module.

Symbol Pin Number Pin Description
SA0 239 Serial Device Address #0
SA1 240 Serial Device Address #1
SA2 101 Serial Device Address #2
SCL 120 Serial Clock
SDA 119 Serial Data
VSSSPD (VSS) 118 Ground
VDDSPD (VCC) 238 Power Supply

If your system fails to run you may try to get it to boot by isolating pin 118. In most cases this helps to solve an issue with running the system.

The next figure lets you locate the SPD EEPROM related pins of the 240-pin DDR2 module.

DIMM's SPD pin indexes

There is also another way of recovering corrupted SPD EEPROM device, which consists in hot plugging a DIMM module without the need for pin isolation. So, after POST is complete, enter BIOS Setup utility to get as much time as we need to install DIMM leisurely. Insert DIMM making sure the connector edge of the DIMM aligns correctly with the slot and push down firmly until it snaps into place and both levers close. Now press the F10 key to exit. Upon exiting BIOS choose No to not save the settings. After that your system will not be restarted and Windows will begin loading.

Next run Thaiphoon Burner and make sure corrupted SPD EEPROM is found by the software and presented as the command like Read SPD at 5xh under the EEPROM main menu, where 5xh is an appropriate SPD EEPROM device address on SMBus.

If corrupted SPD EEPROM is not found, you can try to reprogram it by specifying a custom SMBus device address. For this purpose there is the Enable Customer SPD Device Address command under the Settings main menu of the SPD Data Write dialog box.

SPD Data Write dialog box

This allows you to enter SMBus address for the SPD EEPROM device manually.

SPD Data Write dialog box


Project by Vitaliy Jungle
Copyright © 2008 Showshock Softnology
All Rights Reserved

Company Location
Warsaw, Republic of Poland