Moving from computerised to normal amateur telescope?
A Celestron Nexstar 130 SLT is not suitable for spectroscopy and the only photography that it will be mush use for would be afocal or DSLR imaging of the Moon (or Sun with a suitable filter).

For more serious work you will need a equatorial mounted scope with a better focuser.

Exactly which one to choose will depend of your budget and what you want to do.

When you say the computer does not work can you be more specific.