Onkyo C-7030 CD player giving "no disk" after disk inserted

I am having a problem with my Onkyo CD player. Often when inserting a home-burned disk (and very rarely a commercial disk) the disk spins up but then gives the error "no disk" (or sometimes error "99"). Occasionally I can get the disk to play either by putting it momentarily on top of our wood stove to heat the CD, or by physically putting a bit of upward pressure on the CD tray after loading the disk in the player.

I have tried cleaning the lens with one of those commercial CD cleaning disks, and sometimes that seems to have an effect, but only at the specific time. The next day the problem is back. Also sometimes resetting the player to initial specifications then re-inserting the disk helps. In short, it seems all very mysterious. The CDs play fine on the other players we have in the house and the car. Anyone have any ideas of how I might try to fix this, or is the laser just crapping out?

I realise that perhaps for many people, CD players are a thing of the past. But we are music lovers with many, many hundreds of CDs and would be grateful for any ideas!

I fixed the problem by installing a new laser module. I wrote a guide while doing it :-)