How do you fix an audio cassette tape that plays through most of the tape but slows down or stops completely through certain area of the tape. This has happened with two tapes so far. Maybe for 5 to 10 minutes or less about two thirds through the tape on one of them and towards the end of the other. Both tapes are older AMPEX 90 minutes tapes. I am trying to record some 20+ year old live recordings of one of my bands onto my computer hard drive and then preserve them on cd's or dvds. I have cleaned the heads etc of the tape player. These tapes haven't been played for years. I've been saving them for this purpose. The player is an AIWA HXPRO with low hours that I bought from a studio for this particular purpose.
I have taken cassettes apart and replaced tension springs before but I don't want to mess this up and wasn't sure if someone could tell me the best way to proceed would be.
Thanks for your help!

Marty Prue, February 2007

Try placing the "sticky" cassette in a container with some silica gel (not IN the silica gel); comes in pill bottlles, used to dry flowers, gun shops often have larger containers of it. Removes excess humidity from tape.
Then try...
fast forwarding and fast reversing through the entire tape.

kyle uhland, December 2007

first test on a differemt deck. if they play ok, chances are the pinch roller in the aiwa needs cleaning or replacing.
if still sluggish the tape binder has broken down, this is tricky as ampex used whale oil between approx 1975-1983 in the manufactuing process, which has not aged well. you may have to 'bake it' - google tape baking.-
good luck.

romko, February 2007