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Quadra 840AV Locking Up

ianj

Well-known member
I've given the case a few decent cleanings lately, but I'll go in there again and try checking for metal particles and such.

Regarding all this hard drive stuff - I'm pretty sure I set the jumpers on the new drive right. It came with one jumper, which I put on the pins marked for "ID BIT 0," which I assume is the one I want. It sounds like there's a lot of ifs with internal SCSI devices here; could I just disconnect the entire SCSI chain from the motherboard and run it with just the floppy drive to eliminate that potential for error, or will it refuse to start up without that attached?

 

wally

Well-known member
Re: disconnecting SCSI and trying the floppy alone, I believe what you are proposing is a sound experiment: try it. Most 68K Macs will show the blinking question mark floppy icon if the floppy drive is empty, and will try to boot from the floppy disk alone if you have a valid one inserted for your particular model. What I find appealing is that you can easily try it repeatedly under a wide variety of situations, from a cold start, many consecutive times, and after sitting on for hours, and the behavior should be identical each trial if the motherboard and power supply are good. If you get discrepant behavior on power ups, there are fewer suspects. You can also try with no floppy drive, and look for consistency, and try a hard drive boot up, no CDROM connected, and without the floppy drive connected.

 

Maccess

Well-known member
Have you checked your RAM speed? The 840AV requires 60ns RAM, most other quadras get by with 70ns RAM. Your RAM could be failing.

 
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