I recently built myself a machine up from using a ASRock K7S8X motherboard and 512mb of DDR400 ram.

I purchased this on the 28th of August and all has been well until this last weekend. When my son switched the machine on this Friday evening all we got was 3 short beeps, so I switched it off checked all leads were connected properly and switched it on again. It then worked fine until Sunday morning when it reoccurred so I check the beep code list I have for the amibios, this stated that it was base 64K ram failure so I when out and purchased some more ram to check this - took the original ram chip out and put the new one in no difference so I am now wondering if this is the board.

I phoned the company I bought the board and ram from and spoke to a man who's first question was "had I checked the graphics card?". Now this may be a silly question but what has the graphics card to do with it? Does anyone have any idea before I send this back to the company for testing?

Three beeps is often a no video error code... switch it on and press num-lock and or Caps-lock. If the system is working then the num and caps lights should go on and off, they wont do that if the system board is knackered.
Reseat the video card or try a different one.

Thanks neeeeeeeeeek I will try it later - I'll put it back together again the trouble is I don't have a spare graphics card to check it on unless I can get my son to agree to let me borrow his, but the list of beep codes I have for the amibios show this as a memory problem.

As Neeek hinted, chances are the graphics card just needs taking out and putting back in, making sure that the contacts are seated properly...

Sometimes cases aren't particularly well built or the graphics card metal slot cover has been bent a little too low and the card gets forced out of it's slot just a teensy bit at the output end. It's a pain in the butt and as a result something as benign as a gentle nudge of the machine or kick of wires can result in the card shifting out of contact position.

Worth trying that first before getting another card.

Would be well worth stripping system back as far as possible. Remove any additional cards and all bar one stick of RAM. If possible, source some known working RAM. Essentially get it back to mobo, cpu, RAM (and possibly a single HDD (don't worry about CD/DVD or floppy)). Carefully reseat the graphics card, CPU and RAM (try the RAM in a different slot as well if possible).
You should then be able to eliminate at least some of the components. If it'll let you into BIOS, try any "Safe Configurations" and see if you can get it any further.

Thanks alot I'll try your suggestions. At the moment I have taken it all apart again anyway as I was going to send it back so I will try rebuilding it and see what happens. I might buy a new graphics card anyway as the one I have causes a flicker on boot up - driver conflict I think (it did the same on my son's machine - it's a Geforce MX440).

I'll let you know the results.

Well I tried all your suggestions but still no luck tried both stick of ram and no joy. Neither the number or caps lock came on so I presume that means it is the board since the second ram stick was only purchased yesterday I can only assume that this is ok. Oh well, looks like I'll have to send it back. I've got my laptop back now from the friend I had lent it to so I am now able to get back online at night (apart from by using my son's machine).