In bios on my old Pentium based motherboard

[Philippine Mango]

Hi have an old system which is pentium based with a AMD K6-2 450MHZ processor and recently I have been having problems. I haven't used this system in a while and I start up the system and it get's to the desktop but then later does a hardreboot. For a while there was no video on the screen and I opened it up again and powered it on, now there is video but I got to the bios and as I was navigating to change some settings the text changed from for example an "A" to an @ and other wierd character changes then the computer froze. I'm now asking what should I do and what could be the cause of this problem, I have 3HDDs and 1 optical drive. 3SCSI drives and 1 IDE, the floppy drive doesn't work anymore and I have no idea what to do.