n138ct@tamuts.tamu.edu (Brent Burton) (03/02/91)
I don't know how many people have been reading my barrage of updates on
my problem, but I hope everyone made it this far.
I received many replies with several hints and things to check; however, just
due to the sheer number of ideas, I was bound to miss one.
Last night, when the machine finally came back up, the voltages were measured
at the pwer supply while it was running and also when the machine wasn't
booting.
After poking around during a no-boot condition, I pushed the ribbon cable
on the power supply towards the center of the machine and the 7300 started
to boot. I then measured the voltages and they were correct. I released
the ribbon cable and pin 18 goes from -12.0V to +0.79 -- bad solder joint
or connection.
This was one of the earlier suggestions I received (thanks, Don!) and that
I just happened to miss over.
I think the bad connection is the actual pin on the power supply and not the
connection on the motherboard. I'll get it fixed now.
I'd like to extend my thanks to everyone who gave me ideas. Being a new
7300 owner, I was anxious to learn more about my system, but now I've had
a crash course with the hardware.
Once again, thanks everybody!
+----------------------+--------------------------+
| Brent P. Burton | n138ct@tamuts.tamu.edu |
| Texas A&M University | Computer Science/Physics |
+----------------------+--------------------------+n138ct@tamuts.tamu.edu (Brent Burton) (03/02/91)
Sorry for the excessive use (certainly not a waste IMO) of bandwidth.
I removed the power supply board and pins 17 and 18 had broken solder
joints (they really didn't have much solder at all). FIVE other pins had
cracked joints but they weren't broken yet.
I resoldered all the pins, checked the rest of the power supply's joints,
and started it up.
The system has been turned on and off several times and it has never failed.
It is currently running happily.
+----------------------+--------------------------+
| Brent P. Burton | n138ct@tamuts.tamu.edu |
| Texas A&M University | Computer Science/Physics |
+----------------------+--------------------------+