Usually, everything works fine. Occasionally (twice this week already) my monitor goes black. The computer is still running fine, I just can't see anything. I replaced the monitor hoping to solve the problem, but no luck.
When this happens, I disconnect from power, then reboot. At re-boot, I make it past the memory test OK, but before it can finish booting up, before testing extended memory, all goes black. Boot up continues, I just can't see it.
After several re-tries, it will finally boot up complete with display.
Today all ran well for 16 hours, then, while doing a backup -- black screen appeared. Earlier this week it happened when I touched the spacebar to terminate the screen saver (Razzle Dazzle).
This is a 486 dos set up, about 6 years old, used as a cash register.
I had a pretty old RGB monitor; replaced it with a new thin flat screen Samsung.
Any ideas? If you're getting ready to tell me to buy a new computer, I worry that my DOS cash register program won't work under windows. It's a perfectly excellent program that I don't want to give up. Windows seems so touchy; DOS has been rock solid for our store situation.
Thank You all for your ideas, I'll just have to wait for the problem to happen again to try your remedies.
One more symptom I just remembered: One day, twice in a row, as it was booting up, it reported that the memory test failed. At the third try to boot up, all went well and has been OK for a week. Was that just a quirk or maybe related to my blackout problem?