Radeon X1300 Hardware Issues

Posted by Hans de Ruiter

It looks like my Radeon X1300 graphics card has faulty video memory. 8-bit and 16-bit screens have vertical lines in them, eight and four pixels apart, respectively. After performing a memory test, bit five of every of every eighth byte remains set to one, regardless of what is written. This defect is invisible in 32-bit truecolour mode since that bit is part of the invisible alpha channel. The Visiontek Radeon X1300 that I have has a 64-bit memory bus, i.e., eight bytes wide. Thus, this behaviour is consistent with a single data line being faulty; possibly a bad solder joint or something similar. Unfortunately the memory chips are fine-pitch ball grid arrays, so it is not something that I could fix. An x-ray machine would be required to even check if a solder joint was bad.

For the technically minded, the memory test wrote rows of all ones and then all zeros to memory, and then read them back. Writing eight bytes of zeros, i.e.:

00 00 00 00 00 00 00 00 in hexadecimal,

returned the following:

00 00 00 00 00 00 00 10.

This same pattern occurs throughout the tested memory area (I did not test the entire 256 MB). 

For now, I have returned to using the Radeon HD 2400 pro. The registers for sprites and overlay are the same for both R5xx and R6xx cards so those features can be added without any issues. 

Comments (0) | 16 October 2008