GXS-700 Internals

Thanks to the great blog by John McMaster (uvicrec.blogspot.com) I knew of the intraoral dental x-ray sensors sold by Gendex and Dexis. I liked the post so much that I bought some of these that were offered at eBay as non-working or calibration files missing.
The driver provided by John allowed to connect to the sensors and play around, but the test for "dark" image indicated that the sensors where not working properly. This was not a surprise for the sensors listed as non-working, but I did expect that one listed as "missing calibration files" would work, as the original software requires the files to work, but John's software doesn't.
Some of the sensors seem to provide random noise while others provide a black image. Having non-working devices I decided to investigate if I could find the reason of the failure, as while some sensors looked like abused at least one looked like new.
One of the sensors was heavily abused with visible damage on the outside (this was unfairly listed as not-tested, despite the fact that the phisical damage was evident...beware of chinese Sellers!!).
This one did not enumerate when conected to a PC, so I decided to open it up, revealing shuttered sensor and scintillator glass, and also a bent PCB, which would be the main cause of electronic failure due to broken BGA solder balls.

You can find details of the Gendex GXS-700 sensor in the Wiki (another great job done by John McMaster) at www.siliconpr0n.org/nuc.

Despite the great detail provided in the Wiki I found out some additional information on the components of the PCB.

The highlighted ICs are:

• Actel ProASIC3 A3P250 FPGA (yellow)
• LTC2355 Serial 12-Bit/14-Bit, 3.5Msps Sampling ADC (green)
• MT45W4MW16PCGA 64Mb: 4 Meg  x 16 Async/Page CellularRAM (purple)
• CY7C68013A EZ-USB FX2LP USB Microcontroller (orange)
• LT3547 Dual Monolithic 300mA Synchronous Step-Down Regulator (brown)
• Microchip 24LC64 8KB serial I2C EEPROM (red)
• Spansion FL128PIF 16MB SPI Flash (blue)

The I2C and Flash contents (it looks like only a very small área is used) can be retrieved using John's software (more on this on next entry).