|"Is it possible for Sony to have made it so that only Sony parts can be used in there machines? "|
No, not in recent times.
Brand name systems builders of desktop systems almost always don't make their own mboards - they are supplied to them by major brand name mboard makers and often the only difference is just that the bios is a Sony version.
In fact you can often find the actual mboard makers model, and sometimes the maker, printed on the mboard in plain sight, often between the slots.
Look for that and tell us if you find anything.
"I bought a brand new Sapphire ATI Radeon 9550 256Mb AGP graphics card and put it in the computer. But it won't POST..."
If the AGP slot in the mboard is 4X/8X or 8X compatible ONLY, a card that has 2X/4X/8X capability may work, or it may not, despite the fact you may have no problem physically installing it in the AGP slot, depending on which main chipset you have. Cards with ATI chipsets almost always have a physical universal slot configuration on the contact edge that fits in universal AGP slots and in certain other slot types.
With certain chipsets using a 2X/4X/8X card in the 4X/8X slot will result in a card that won't work, and doing that can damage both the AGP card and the circuits connected to the mboard AGP slot.
The ATI 9550 chipset on the card is 2X/4X/8X compatible. Sapphire was poor information on their web site about their cards and all it may say is it's 8X or 4X/8X capable, but I know from previous research the 9550 chipset is 2X/4X/8X compatible.
Whether it is actually wired to contacts on the card edge that are for 2X is up to the clone card maker, but usually they do wire up everything.
It works in the other computer because that other computer's main chipset doesn't have a problem with a 2X/4X/8X compatible card and the AGP slot's circuits.
"...it doesn't like the first AGP Ti4200 i tested it with..."
Maybe for the same reason.
"There is no onboard video to contend with..."
So that's not the cause of the problem with the PCI card.
"...or an option in the BIOS to switch between AGP and PCI,"
When you don't have onboard video sometimes that option isn't in the bios - it's supposed to be detected automatically.
When you do have onboard video on more recent mboards, the onboard video may be AGP too, and/or you may have a different setting such as onboard video/video card in a slot, or similar.
There's also the possibilty very recent mboard chipsets may not support PCI video cards at all - I know some won't work with older than XP or 2000 operating systems.
Since the AGP card that does work in Safe mode okay, but has lines in normal mode, it could be the AGP circuits on the mboard were damaged by the same event that damaged the card.
You could try:
See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
While the the AC power is still removed to the system, using the same cleaning method to also:
- clean the contacts in the AGP slot.
- clean the contacts on the AGP cards, and any other cards.
- load bios defaults in your bios Setup, especially after you have flashed the bios, to make sure the information and settings the cmos is correct