I do NOT accept work on any machine less than 166mhz, and do not like working on those.
The old machines tend to give erratic problems like the mouse not working on one boot, the sound on the next.
Very old machines are likely to have been struck or shocked by high voltage, seen it several times and they give different symptoms each boot as seen above.
Units with failure to boot, no video etc, I accept them for inspection.
I will hook them up to kbd, mouse & monitor and if I cannot determine which direction to head, I give it back at NO CHARGE.
If the customer insists that I attempt more detailed teardown, it's $20.00 per hour, $20 minimum.
Usually on older stuff, I'll wind up using the good components to assemble a more modern machine.
I still sell 400mhz machines, I sold one 233mhz this year and the customer is very happy with it. It was CHEAP.
You can sometimes spot "problem" customers.
1st time users are best avoided.
People you work with who complain about all the utility bills etc, avoid them like the plague.
One whiner at work has asked for pricing for a year, he did not want to spend over $300 MAX.
Then went out a got a new Dell for $1200.00, I was so GLAD