[3DGraphics]

I recently acquired an Indigo 2 with IRIX 6.2 installed. The system worked fine with the previous owner.

I was able to have the Prom load but after that the screen would go black as IRIX started booting. I believed the problem was that the monitor was not sync-on-green. After trying mutiple monitors with unknown SOG status with the same result I finally got a confirmed sync-on-green compatible model yet the problem remained.

A few days ago I ran the Diagnostics in the prom. It ran for a few minutes and appeared to freeze, I walked away and shortly after noticed the machine restarted itself so I don't know what info showed on the screen. I ran the Diagnostics again, this time it froze for a long time and did not restart. During this time the LED alternated between steady green and flashing green. I manually restarted with the switch and the machine booted into IRIX. 

I played around and tested some stuff. I ran Alias 8.5 which seemed to work fine. I left the room for 35 minutes to eat dinner and when I came back the monitor was black with the indicator light blinking meaning no signal. I tried the mouse, keys, but nothing worked. The LED light was green. I'm pretty sure it wouldnt turn off by the power switch I had to restart it with the switch and then power off in Prom.

Today I tried again, it loaded right into IRIX. I was able to login into root via Unix Shell to change the date. I just explored the DesktopHelp and after about an hour tried to run the text editor Jot, I clicked the icon and immediately the screen went black indicating no signal detected. Again couldnt revive the system via mouse or keyboard.

After restarting the system it did not successfully boot IRIX and went from Prom to black again as before I did the Prom Diagnostics. I expect if I run the Diagnostics again I can get it to play nice, but only for so long.

I don't know if the system crashing when a certain program is loaded is indicative of a hard disk problem or what. There was certainly some jostling during transit as the hard disk ribbon cable had come completely disconnected from the connector near the processor. I tried making sure everything else was secure but I have no experience with such things and didnt see anything that looked wrong.

I have never used Silicon Graphics computers before so any advice would be greatly appreciated. Thank you.