Simply put, this was a budget unit from new and it’s a poor idea to invest more money in it ,
The FMV of the unit in working order is a nominal amount that faces expensive pro tech time costs at prevailing rates. Add in the further cost of a replacement laser unit (…if you can even still source another one ,,,) and you under water cost-wise from the get-go.
MY TAKE
Accept that it has hit its end of useful life and the expected repair costs kinda kills a reason to plan any repairs, so just move on. You can easily find a better unit for the expected amount you will face to attempt repairs.