American seller
member for over 20 years

How can this be BETTER than NEW?
The original rechargeable NiCd barrel battery (prone to leak and cause damage) has been removed and the CMOS battery circuit upgraded to a modern CR2032 lithium battery — easy to replace, widely available and inexpensive. No more danger of damage from leaking battery! The charging circuit has been disabled (CR2032 is non-rechargeable) and the reverse current blocking diode has been upgraded to a premium Schottky for longer battery life (measures only 0.08v drop). The board itself is in pristine condition with zero corrosion.

RARE Soyo 25P2 486 AT Motherboard, ISA/VLB, 256K Cache
UPDATED VERSION — Supports 486DX4/100 (see screen captures)
SiS 85C471 chipset, Award BIOS
Manufactured March 1996
All cables (FDD, IDE, Serial, Parallel) INCLUDED.
FULLY TESTED
GREAT CONDITION!

• As an OEM, we purchased Soyo motherboards directly from Soyo for our own PC production.
• This board was removed during a routine upgrade decades ago and has remained unused, packed in protected storage ever since.
• Sold without CPU and RAM so you can configure as you wish.
  • CPU core voltages supported: 3.45v, 5.00v
  • FSB supported: 25, 33, 40, 50MHz
  • VLB wait states supported: 0, 1
  • Up to 128MB — 1, 2, 3, or 4 banks of 72-pin FPM SIMM
• Fully tested using Ultra-X professional diagnostics (see test results attached).
• NO CORROSION.
• Includes — universal floppy cable, supports both 3.5" (pin connector) and 5.25" (card edge) floppy drives.
• Includes — dual IDE cable, supports two drives.
• Includes — IBM parallel and DB9 serial header cables.
  • Note: Not widely known is there are TWO standard configurations for COM port headers: DTK and Everex (AKA staggered and sequential) which are completely incompatible with each other. Using the wrong header cable won't work at all (the signals will be on the wrong pins). Most online sellers do not identify the type they're selling, which can lead to immense frustration if it's the wrong type. The included DB9 header cable is correct for this board.
• Printed copy of full manual — High resolution scan of original manual with all jumper settings. The updated jumper settings to support the DX4 and other new processors are incorporated into the manual.
  
• 30 day warranty.

You will receive exactly the item you see in the photos.

Shipped via fast USPS Priority Mail with full tracking. Shipped from a USPS SCF (Sectional Center Facility) so delivery anywhere within the U.S. is only a few days away (excluding the occasional USPS misdirect).

NOTES ON TESTING:
• All low-level core functions are tested with Ultra-X professional diagnostic software specifically designed to test these early motherboards.
• Tests included a burn-in loop of more than 10 minutes (see attached report for list of tests performed).
• Memory slots fully populated so all memory slots are tested.
• For practical reasons, I cannot test every slot, memory combination, processor, header, port, or configuration, etc.

RETURNS:
• Sold with 30 Day Warranty — If the board fails or a defect is found within 30 days of purchase, I will stand behind the product.
• Please contact me with details of any issue so we can resolve the problem or work out an appropriate solution.
• I will provide a reasonable amount of technical assistance if you have questions concerning the configuration or proper use of the item.
• Buyer's remorse returns must be in original condition, in original packaging, and may be subject to a deduction to cover the cost of retesting.
• Generally, the original shipping cost will not be refunded.