Server wont boot

My server 2003 crashed. Ive made no changes to it. When i restart, sometimes ill get video and then itll get stuck somewhere during loading. Sometimes no video. Sometimes it wont make it past the bios boot. Once it did and displayed ‘starting windows server 2003’. Another time i got an error saying ntldr is corrupt.

Any idea if this is a motherboard or power failure or is it a operating system problem. Will reinstalling server fix the problem?

thanks