Also my first computer, bought as a kit and I soldered it together. Mine lasted a long time. It was so limited though I learned Z80 assembler, which turned out to be really cool. The ZX-81 was a wonderful machine.
The ZX81 was also my first computer. Have to say I must have better luck because mine is still going to this day (although I did recently need to service and fix it).
Those were wild little toys; and people stretched them beyond all reason.