Centris/Quadra 610 Reboot Issue

[tatdude806]

OK I couldn't find anything on this topic, or not close at least. I have a Centris 610 with the Quadra 610 MB upgrade (16mb ram, 512K Vram, 500mb HDD, System 7.6) :approve: . When I power it on, I get the happy chimes, a happy mac, hard drive starts pulling data then it reboots 5-10 seconds after happy mac shows up xx( . After reboot, Chimes, Happy Mac, then it boots completely up. I am not sure what this is. All the caps on the board are good, the pram battery is brand new, and there is no other issues. Am I making a big deal of this, or is this a legitimate problem that someone knows something about?

 

[coius]

Is there an extension/INIT that loads at that time? Possibly in there due to maybe someone installed an upgrade that if it's not presently there, it might force it to reset and load without the extension/INIT plug in.

I know some G3 upgrades for the PCI series powermacs did that. It would start to load, then reboot (and it installed the firmware into the PRAM to support the upgrade) then it would reboot. Try booting off a floppy/CD and see what it does. It might be something loading. Also, check the power supply. It might pull too much power when the hard drive spools up and the power supply cuts short causing it to restart. Remember, the startup of any machine is usually the worst load ever put on the power supply. This is because so many things (floppies/HDD/components) starting up and surging the power at the very instant they start powering on, and they usually do it all together at once.

So either try booting from a CD, or get out your multimeter and start testing the DC out from the powersupply and when it restarts, see if there are any anomalies right before it reboots.

 

[Charlieman]

Take a look at the power supply and psu fan. If the fan is sticky, it can pull down the psu or trigger the thermal sensor.

As Coius mentioned, there are lots of INITs that force a reboot (eg PRAM reconfig utilities).

 

[tatdude806]

Ok well it is not the power supply, tested it and it checks out fine. No issue from floppy... (No CD rom in this one) Should I zap the pram or just start digging til I find the one that is causing the issue? And I should mention this occurs before I ever even see the MAC OS screen.

 

[coius]

Zapping the PRAM is usually one of the first steps in troubleshooting. You might want to pull the drive and any upgrades. If there is a network card in there, pull that. Try pulling the harddrive and booting from a floppy. If it reboots off the floppy, you might have an issue with capacitors where they drop out.

I seem to recall that caps fail in weird ways where they will take a while to start up, or they will require running and then restart just to get them to work. or they will run fine for a while, and then all of a sudden you get stability issues.

Not sure what to tell you, but start with zapping PRAM and pulling all items except the board and a floppy. that will tell you more than guessing

 

[Byrd]

Also check your SCSI IDs/termination, and try an complete OS install. Does it do the same with extensions disabled? (hold down shift at startup)