Before you fork out a wad of money, try cleaning the lasers lens as mentioned in a few other threads. Also ask yourself, "Are my disks scratched". ???
I nearly sent my PSX off to be fixed and on closer inspection found that the primary problem was/is scratched cd's. As per similar thread, I'm of the opinion that when the PSX gets a little long in the tooth, it may experience problems with reading CD's with scratches that were never an issue before.
I have had mixed results with repairing scratched discs with a 50/50 success ratio ???