A system timer failure is rather uncommon. The 4 beep POST code can also mean, on a AMI BIOS motherboard for instance, that there is an error in the first bank of RAM.
Check your SIMMs / DIMMs to make sure they are seated properly and fully. If no change swap out the memory in the first position for another one and try again. Slowing down the RAM system in the BIOS Advanced settings may also help in getting a response. Your mileage may vary...