|"Diamond Stealth S120 256mb AGP card"|
Apparently there are two possible models.
- the one I found in response 4, which IS a Radeon 9250 card
DIAMOND Stealth S120 AGP 256MB (home support page)
NOTE the category it's listed under
Products > Video Cards > 9250 > DIAMOND Stealth S120 AGP 256MB DDR DVI & TV Out Video Graphics Card
Note there is NO obvious Radeon 9550 printed on the box it comes in.
- and another model, which has the Radeon 9550 chipset
Diamond has no info about the 256 mb version, but there are ads.....
...and reviews for that version on the web that mention Radeon 9550.
I have encountered that several times previously - Diamond having no information about one of their models.
Support for the 128 mb version of it here:
NOTE the category it's listed under
Products > Video Cards > 9550 > ATI AMD Radeon™ 9550 DIAMOND Stealth S120 AGP 128MB DDR DVI & TV Out
Note the obvious Radeon 9550 printed on the box it comes in.
ATI AGP Graphics Cards - AGP Compliance Details
RADEON 9550 1.5V, 0.8V 4X, 8X
The Radeon 9550 chipset does NOT support 3.3 v, 2X mode
Which version of the S120 do you have ?
If it has Radeon 9550 on the box it came in it should work fine .
Did you REMOVE the AC power to the case / power supply AT ALL TIMES when you were plugging in or unplugging the S120 card ?
If you DID do that at all times, did you WAIT until the led that is probably on the mboard goes out BEFORE you plugged in the S120 card AT ALL TIMES ?
(Most mboards have an led that is lit up when the power supply is receiving live AC power, whether the computer is running or not. It's there to remind you that you MUST remove the live AC power to the mboard whenever you are plugging in or unplugging anything that connects to the mboard or the power supply inside the case. After you have removed the live AC power, it takes a short time for capacitors inside the power supply to discharge enough for that led to go out. )
AGP cards and AGP slots have two horizontal rows of contacts on each side that are staggered vertically.
If you didn't do BOTH of those things, the circuits on the card, and sometimes the circuits of the AGP slot, are easily damaged, when you plug in or unplug the card.
If the .
It's also VERY important the the AGP card is all the way down in it's slot and it's metal bracket is fastened to the case BEFORE you attempt to boot the computer.
If it's metal bracket is NOT fastened to the case BEFORE you attempt to boot the computer, merely plugging a video cable into it can easily move the card upward in the slot and damage it's circuits. (Been there, done that, once only.)
I found no manual for the Soyo P41875P, but any mboard that has the Intel 875P main chipset has the same AGP specs.
Intel® Desktop Board D875PBZ
Technical product specification
The AGP connector supports the following:
. 4X, 8X AGP 3.0 add-in cards with 0.8 v I/O
. 1X, 4X AGP 2.0 add-in cards with 1.5 v I/O
. AGP 2X opertation is not supported
. The AGP connector is keyed for Universal AGP 3.0 cards or 1.5 v AGP 2.0 cards only.
Do not attempt to install a legacy 3.3 v AGP card
You CAN plug in an AGP card that has a chipset that supports 2X / 4X , or 2X / 4X/ 8X modes into an AGP slot that does NOT support 2X mode at 3.3 v
Picture showing 1.5 v divider in the P41875P's AGP slot:
Picture of S120 9550 card - has the one slot for 1.5 v:
Picture showing the universal arrangement of slots and contacts on the bottom of an AGP card
ALL cards that support 2X / 4X , or 2X / 4X/ 8X modes have the two slots. SOME cards that support only 4X or 4X / 8X modes have the two slots.
Either arrangement of the slots on the bottom of the card will plug into the P41875P's AGP slot.
Cards with the two slots MAY NOT work in the P41875P's AGP slot !
Video / Graphics Card Problems
Search the page for: note well
"Note well that installing a 3.3V video card into a motherboard designed for 1.5V cards will usually destroy the mboard."