MZR-900 struggles to read discs

[chrisr]

As per title really. I've owned my MZR-900 from new (2001? dunno tbh) and it's been superb, but since a small mishap late last year when a bottle of water leaked in the bag that it was in, it's struggled to read discs that are loaded in to it. What usually happens is that the disc carries on spinning, there are sounds that suggest that the unit is attempting to locate and / or read the TOC, but it doesn't make it. Gentle tapping on the case with a finger tip will usually encourage it, but sometimes the disc needs to be reinserted 2 - 3 times, and the finger tapping exercise repeated, before it finally gets the TOC.

Once it's got it, it works perfectly, until the next time it needs to read the disc - if it's been left to go into close down for example.

I've had it to bits, sprayed a fine Teflon lubricant around the mechanical components, given the lens a blow but it looks clear anyway, and tried to blow any dust etc out with a camera lens airbrush. This all had zero effect on the problem. It looks clean, it works properly once the TOC is read. There's no pattern to using new / old / pre-recorded discs. Any suggestions? Is it just down to age? It may be just coincidence that this started when it got wet, but sensibly that was the likely cause.