Congratulations detective!

I have "Now that's what I call Music 10" on cassette that's from 1987 and it's an EMI tape that does exactly the same on all 4 of my decks!!

Shiny capstans usually aren't a large problem. I would blame the pinch wheel. The capstan actually drives the pinch wheel (outside the tape), which pulls the tape.

Rawn RE- Grip works great on worn pinch rollers. The only time it will not work is when you run into a Sony deck with pinch roller melt. Pinch rollers should be cleaned at least every 20 to 30 hours of use. Also different tapes require more torque than others. Maxell cassettes run smoother and require less torque than cheaper tapes. You also want to FF and RW any tape that has not been played for a long time to help loosen up the tape pack .

I can’t believe I find you. I have the Excelia XK-009 (Europe)and it is a very important and sentimental deck. My brother had inherited and I grew up playing this since 1989. I even recorded guitars with it way back. Now I am an audio engineer and I use it for digitizing or preserving cassettes. I can not stop opening electronics and try fixing them. I had a very hard time putting new belts long ago but now watching your videos are tremendous help. I can’t thank you enough. I am having the opposite issue. The pinch rollers are too tight. As soon as I disengage them it plays fine. I am very curious what could fix these Aiwa’s.

Maybe a thicker pinchroller will help.

I had same problem before locust infestation from the east My 20 years old cassetes had same issue especially LG CD Gallery 1. But my LG cames in transparent case and i remembered heareble flutter right from first record back then. But all others and TDKs plays well. I also realised what i probably badly cleaned capston after lubrication. Thanks, one problem demilished

I think your problem is with the pinch rollers a good cleaning with IPA and maybe some rubber renew to soften them up and it should work.

Another important problem about the welded cassettes is THE TAPE ITSELF ! Especially for these EMI / Capitol (and few other companies) Canadian tapes from the 80's ... they all end up to suffering of sticky shed syndrome , probably because of the tape formulation that can degrade over the years . Especially these ''bubly edges'' welded cassettes (like your David Foster / Naked eyes cassettes ) have this kind of tape . Even if they play well for now , it won't last unfortunately for these tapes 😔 Another company that have this ''tape problem'' is Polygram (especially tapes from the 70& 80's , again ! 😅 ) and ALL his associated labels distributed in Canada (Mercury / Banzai / Vertigo / Polydor / RSO / Casblanca / etc... - and the ones with welded shells especially )

you see where its says "XDR" on the tape ? i have several "XDR" tapes all giving me the same issues , not a single deck plays these , single or dual capstan decks from various brands. i took the take out of the welded case and transferred to a TDK case, a Maxell case and a BASF case. still would not play. cleaned the tape itself front to back with IPA 99.9% , still nothing , i baked the tape , still nothing . what i finally did was lube the tape with dry teflon , that worked wonders and now the tape plays again its not the case, its the tape material loosing its lubrication and starts sticking to itself , and all "XDR" tapes seem to start doing this after e "few" years (30 or so)

Maybe not the right thing to do on an Excelia...but I have often fixed similar problems with a brown Scotch-Brite-pad on capstans.

Maybe this is quite silly and not good for all decks. I lightly sanded those capstans and now they are playing those problematic tapes. Not all, of course, but it works.

it wont play the tape because it is wound too tite