I'm not clear about the system you have. A wyse-50 is just a dumb terminal. Sure you can use a wyse-50 with any version of unix. But you say that your unix system comprises just a wyse-50 and a motherboard. That seems very strange. Virtually every version of unix will also require a mass storage device such as a disk.

But in any event, the info you posted is all about the wyse-50, so I guess that you are certain that the wyse-50 is failing.

Dumb terminals just don't cost enough to justify repairing them anymore. There are currently several wyse-60's for sale on EBAY for $10.00 each and no one is bidding.