That is what I did I took out cpu of known good unit. That is where I traced problem too. When I did bad unit then worked properly. So I had CpU rebuilt. When I put new cpu in to the lift that was good before since I left CPU from it in the original lift that was giving me problems. Now the lift that was good now has developed a problem with fans not coming on. There is a small voltage showing at the fan not enough to power them.
Even with brand new fans issue is still there.