ok - I looked at service manual and could not figure out much. so I opened the owner manual and it says if you are not able to control speed enough from the knobs, there is another two screws below the platter to control the switch. This sounded like good news and I was determined to carefully screw it. Oops I meant unscrew it.
So I found a small screwdriver. Pulled off the mat. Pulled the platter with less force, then with slightly more force - and ultimately the platter came off. I tried to find the screws but they were not visible. So I decided to unscrew another set of 4 screws that held back a thin metal plate. Removed it successfully. Below it I could see what those two screws for 33 and 45 are. First I adjusted them to the reverse direction of the knobs. Patiently screwed back the metal plate, then put back the platter, then rubber mat, played 45rpm - played perfect. Ok so I have not screwed up what was working. Tried 33rpm and it was slower. ok - so I now decided to turn it the other way round, the same direct as knobs outside. I kept the suspense for the last
Unscrewed everything, turned the screw anti clockwise, screwed back, and then put the platter, rubber mat and then played again. Well it did get a little faster, but still not listenable. So all effort gone waste. But the speed is slightly faster than earlier.
I then decided to measure how much difference is there in RPM. It is currently 25rpm (actually I counted for 2 mins and it came to 50 - to reduce least count error). At slowest pitch value (adjusted by the know on the top and the inner screw is still at max rpm) it is 24. Damn was it 24 or 22? Can't really recall. But the difference is quite audible - I tried giving the rotation a helping hand, by putting my finger on top of the record label, and helping in rotating faster. Did not take much help to reach the right speed.
So to summarize - nothing is solved as yet.
Good thing - Platter rotates quite smooth. Speed also seem to be stable. And the table can rotate faster - it works for 45rpm. So maybe some adjustment somewhere can make the platter rotate faster. The adjustment just needs to be pushed more.
Bad news - it doesn't work as yet. I don't know if I will be able to make it work.
Could the IC be out? I doubt the IC is out at it seems to work fine for 45rpm. Why I think so? Because the logic on the chip should be generic, and not rpm dependent. How much feedback current voltage is provided would control the pitch in %age relative terms. It could be a variable resistor that could be the problem? This is just a guess from an optimist who thinks his TT may work again, and from a pessimist who thinks engineers/ programmers won't bother writing logic for two different speeds.