Here's the description and pictures for my A7M266 5-FID multiplier modification for Palominos/Tbreds, first described in the amdmb.com Asus forum. I've now confirmed that this mod can support a 2700+ Tbred and XP-M.

To do this mod, you'll need basic soldering skills; a guide can be found here. If you're still not confident of your soldering skills, please do not perform this modification, as you might completely destroy your motherboard and/or processor. Please turn your computer off first and then proceed with modification. This is a risky procedure, and I take no responsibility if anything bad happens to your computer system.

The original circuit for the 5-FID board is described in John Carcich's site. For this mod to work, the L1s need to be closed.

The following parts were used:

• PCB and 10 100 ohm 0.25W resistors from Radio Shack
• Jumper pins from an old unused PCI IDE card (alternatively, you may choose to use a dipswitch, such as a Tri-State
• 7 stripped IDE cable wires or other types of thin wires (<22g) that you may find
• a soldering iron with a pointy tip

Modification

1) I started by constructing the 5-FID board, shown below.

When completed, I checked all soldering points carefully for mis-terminations and short circuits.

2) The next part involved soldering the 7 wires from the 5-FID board to pins AN27 (0.5x), AL27 (1x), AN25 (2x), AL25 (4x), AJ27 (8x), Z30 (VSS) and X30 (VCC), as shown below. I then checked for possible short circuits by measuring the resistance between the neighbouring pins. The A7M voltage regulator circuit produced a VCC/VSS resistance of 15 ohms.

3) The 5-FID board can be mounted anywhere (please check for possible short circuit when placed near metal chassis); mine is secured onto the topmost RAM hole via a 1 cm nylon spacer. Finally, I checked for connectivity between the pins and the 5-FID board, and remeasured resistance to adjacent pins, making sure again there's no short circuit.

I've used a Tbred A1800+ initially to test the mod.

Results

Thanks for dropping by and happy modding!!

First written 5 Dec 2002

Updated 20 Jan 2003: 2700+ support and overclocking.