no post no beeps

Hi all
I have just got a (promised as working) second hand mobo.Its a gigabyte GA-7VT600 socket A. I got it coz the ATX power connector on the previous machine was partly melted but it still booted.I moved the PCU AMD Athlon XP2600 into the 'new' board and connected it.No beep .I connected a speaker,no Bios but fan spinning and some hard drive activity,clicking. RAM light is on too.512mb of DDR 2700 RAM. Have tried RADEON 9200 and RADEON 9600 vid cards.Have re-seated CPU after cleanining it with Isopropynol and using new compound.Have tried booting without RAM,without vid card.Have laid mobo on cardboard outside of case using various combinations of the above.It is doing my head in! Icant get it to boot into the BIOS.
There is on 'jumper' on the board which has a off n on switch.I have tried both.Are there any other jumpers on this board that I can change to try to get it to ,at least ,boot to a BIOS?
PS
the vendor has assured me that this board is OK.
Please help...............Thanks

 

I would test your power supply or swap it out. It may have worked with the previous power supply but not the one your using, you said the connector was melted. It may not be making contact, check the pins/plug for a good connection.