IBM 5110 help please

Merry Christmas. I’m a new member joined today. I have managed to purchased IBM 5110 few weeks back. It has been sitting in an attic for so many years of the previous owner. I gave it a good bit of clean and checked inside before turning on. I’m not computer geek but I have some knowledge of computer and technology. Beyond safe side I have checked and then turn the unit on. It’s started with fan spinning noice but nothing on the screen. Then I test the switches on the front panel and still nothing on the screen. I left it running for about 15-20 minutes and still no display. I was wondering if any one can assist me on how to get it working/ to identify the fault? I really appreciate any input. Thank you in advanced



Welcome! I will guess that you’ll get useful feedback if you post over on VCFed forums - many more machine-specific enthusiasts over there.

However, I see from the System Maintenance Analysis Procedures manual, in the 0900 section, that you should get characters on the screen some 25 seconds after power up:

So, if your system is in the best possible state, it might only be the CRT that’s not working. Perhaps you have an oscilloscope and can see if there’s a video signal from the BNC connector?

There’s a thread over on VCFed about a CRT problem:

I would think it fairly likely that there are other faults - I would suppose checking the voltages from the PSU would be a good start. Perhaps there is a CPU clock signal that can be checked, or address lines which can be probed. There’s usually a great deal to know, and it’s all very machine-specific.

(The Computer Maintenance Information manual might be helpful.)


Thank you for the info EDs, really appreciated.

Thanks for sharing these useful URLs. It seems the best test for me is inspect the current CRT carefully and test the unit with screen using BNC connection. This way I can identify the fault. Will hunt for a bnc screen and once I manage to get hold of one and test will post the result. Many thanks