The switches have all been checked. I'm not sure what you mean about the hook that keeps the doors closed. The doors do not close at all in flight, but will close while on jacks either with mule or hand power. The gear handle does not neutralize, and I do not get an up-lock light. Thanks for the reply. Any other ideas?

George, sounds to me like the door manifold valve is not cycling, you do not say if the nose gear is going up fully, then doors not closing ,or if the nose gear is not going up fully, which will get in the way.
the 'mule' that the shops shops use, is it a piper one or a real Cessna/copy deal with flowmeter etc designed to operate an early 210, as the other brand is just a pump and does not let your engineer know what is really happening in your system
also how long since the door mod? did this cause the problem?

Alain, we didn't get a reply from George Cole back then, so I presume he fixed his problem and didn't need to have our help, or it helped.
If you wish you can email me and maybe I can assist you with this, as I don't check this forum very often. I am an engineer in Australia, with a little bit of Cessna knowledge,
about 40 years.