View Full Version : Booting up the AT&T PC 6300

September 17th, 2010, 07:29 AM
Well, after two years of sitting in it's original boxes, I finally got up to West Virginia to pull the old PC6300 out for a run. I wasn't expecting it to work, but after a quick inspection of the motherboard and daughterboard, everything -looked- OK. So needless to say I put it all back together, assembled the system together, and grabbed my bootdisk.

After a loud click of the power switch, the familiar whirring of the HUGE fan, and up on the screen the quick system check pops up. 128K, 256K, 384K, all flash on the screen, working up to the 640K I have in the system...Then it freezes. Ugh. Every AT&T system I've ever owned has done this to me. After a few years of great service, they have all slipped in to this state. Freezing up at the system diagnostics, freezing when I leave them sit, or even in the middle of a program. And they all share the same thing. I can usually reset the system a couple of times and get a successful boot. And with ALL of them, if I flick the case, or bump it, they freeze. I reset. This time, I flick the case when it's testing the RTclock. Freezes. I carefully insert the boot disk, close the door, reset, and stand still. It successfully boots to AT&T MSDOS 2.11. I am able to type on the keyboard, run the nostalgic "Tutorial" and even copy a few disks.

My attention is called elsewhere, so I turn down the mono monitor and go about my business. I come back a few hours later. I wanted to leave it run awhile. But sure enough, all I type on the screen is "GWBA" and it freezes. Ugh. A bad storm was coming, so I just shut it down and unplugged the system.

Have any of the other AT&T PC6300 or Olivetti owners dealt with and/or solved this issue? If not, I guess I'll be breaking out the lengthy tech manual and start diagnosing. This system means the world to me, as it's the most complete system that I am aware exists. Complete with boxes, packing materials, receipts, maintenance records, and even loan documents to get the system.


September 17th, 2010, 03:38 PM
Dry solder joint/s ?
See http://www.tegger.com/hondafaq/mainrelayoperation/badmainrelay.html for an example.

September 20th, 2010, 12:26 PM
Are you booting off a hard drive or the floppies when it freezes? Basic troubleshooting would be disconnect things (hard drive) and see if it doesn't lock up and maybe find the faulty part unless it's an already bad cap or power supply issue (load based).

September 25th, 2010, 05:34 PM
Floppy disks. No HDD in this system, but I've seen the same thing in HDD systems. I'm going to do some basic testing of the PSU when I get the chance, and do a close visual inspection of the circuits when I get the chance.