The Short Answer: Yes a bad cpu can give you a good Power On Self Test Chime. What you do is keep downclocking the CPU till it eventually gives you video and boots. You may even have to go to the lowest setting your motherboard allows before it does gives video and boots. If a CPU has been heat stressed in the past, it may say that it is a 500 MHZ processor, but may work just long enough to pass the P.O.S.T. and give a chime, and then lock up (at its 500 MHZ settings). Lower clock speed = less heat = more likely to boot.
(For the archive). Thanks all that helped with this problem. Gus. On Jul 20, 2:19 am, Gus <gusr...@comcast.net> wrote: > System: G4 Yikes with 400mhz Processor clocked to 450 / 750 mb > memory. a PC keyboard hooked to the USB port. PC mouse hooked to the > USB port. > > I got this processor from ebay. Says it is a 500 mhz G4. DId a one > for one swap with the G4 on my Yikes board. (left jumpers at 450). > Chime, But no video. No turn over to open firmware. (no cd boot, > no disk activity at all) Cant zap pram (think it is because of the PC > Keyboard) But should I need to? Swapped the 400 mhz processor back > in, and I get video right away. Boot turns over to open firmware and > up it comes. I am not changing any jumpers during the swap and I I > have a no boot cpu and the original cpu that boots fine. > > STRONGLY SUSPECT I HAVE A BAD CPU. > > BUT!!! I am smart enough to know that I don't know everything. Is > there something I am missing with this G4 -> G4 swap? > > Thanks. > > For grins, I did drop the system clock from 400.. then up to 500 No > change with the 500 mhz g4, Still chimes, no video. > > Thanks so much you guys.. You have always been here when I have needed > help!!! > > Gus. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
