Were you able to diagnose what's wrong with your ZX81? Usually it's a simple problem, it just takes a while to diagnose. BTW, if you do want to get rid of it a

Were you able to diagnose what's wrong with your ZX81? Usually it's a simple problem, it just takes a while to diagnose. BTW, if you do want to get rid of it at some point, it would be nice if you could sell it on ebay or locally. The number of ZX81s left will just keep going down and they are quite decent for learning about electronics/digital systems.