Please help me fix my DVD Player!!!

!±8± Please help me fix my DVD Player!!!

Okay so a friend of mine gave me a DVD/VCR combo (Zenith XBV343) for free and all he said was the DVD player wouldn't read any discs. Well I've been trying to repair it and I'm a little stuck. I know the spindle/hub motor works fine, and I know the rail motor that moves the optical pick up (lens) along it's tracks works fine, but no matter what every time you put in a DVD it simply won't read it, it will either say disc error or no disc. I also notice the spindle motor "revving up" when it tries to read, it'll go up and down with no success, and when it gives up and stops there's a grinding noise as the disc slows down. However I'm not sure if these are normal noises or what. I've tried cleaning the optical lens and that didn't fix it, so i'm not sure where to look next. I would seriously appreciate any help, I'm willing to do whatever it takes to fix this. Oh and before anyone tries to tell me it's cheaper to buy a new one I already know this. I'm not trying to save money or anything, and I have plenty of DVD players. I just want to fix this one for the satisfaction of it. Thanks a bunch!!

Please help me fix my DVD Player!!!

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