Dell Dimension 8300 Upgrade

[vaio-fx]

I have a Dell Dimension 8300, it is used as a secondary computer. I would like to upgrade it to PCI-Express x16 and seeing as it has stopped working, now seems like the time to do so. I have found a new motherboard which has PCI-E, it is a motherboard from a Dell Dimension 8400. From the photo it looks as if it is the same size and shape as my current one. Does anyone know if it will actually work? By the way, the problem with the PC is that when I turn it on, the lights come on, fans work but there is no picture on the screen. I have tested the screen, its fine, also tried spare, graphics card, hdd, ram in it with no success, so i guess it the mobo anyway. Thanks for any help.

 

[Computer Head]

Should work... they appear to be sister units and they both are Intel boards. Should work.

 

[vaio-fx]

Thanks. Anyone know if its definately the motherboard thats gone? I still want to upgrade it, just dont' want the new one to arrive and find that it still doesn't work.

 

[lhuser]

They all look different, but usually, all Dells should fit each other, unless you put an ATX board in a MicroATX case. They have the same rectangular BS for mounting.

 

[vaio-fx]

From the look of it, the 8300 and 8400 are almost identical. The motherboard look identical too, except the 8400 had PCIE and 8300 has AGP. One thing I'm unsure about though is which cpu socket the 8300 is. The 8400 is LGA 775, my 8300 currently has a 3GHz Pentium 4 HT, so I was hoping I could just swap it accross.

EDIT: its a 478, so I ever need to repair current setup, or get a new CPU too.