TEAC A-1250 7.5 IPS playback slow

So I am back to the same old question: Why is there a difference between the two speeds? 3.75 IPS is correct, (around 3000) but 7.5 is slow, (around 2625). There is no drag, everything has been cleaned, lubricated and lubricated again as well as trying a new belt and start / run cap. I also used jumper leads to jumper across the speed switch contacts in a troubleshooting measure to eliminate them. There was no change.
It is possible that there may be a problem with the capstan motor windings that are powered when the tape speed switch is in the 7.5 IPS position.
 
is the frequency selector switch in the correct position ?
also the line voltage selector needs to also be set correctly . as according to the manual if set wrong will mess with back tensions .
section 6-6 in the manual

Thank you, yes, I have checked both of those. Frequency selector set at 60 Hz and voltage at 117 VAC.
 
Ok, so you obviously have an electrical issue with the high speed section of the capstan motor. Did you perform the test that dnash asked you to do in post 16? It is very important to do exactly as he suggested, all four spark killers must have one leg lifted at the same time so they are completely out of the circuit then see what the motor does on high speed. Simply bypassing the contacts on the speed switch without simultaneously taking all four spark killers out of the circuit isn't really proving anything. It could be the motor winding but it could also be a failing spark killer allowing current to bypass the speed switch (more likely). Only way to tell is by eliminating the spark killers and see if the high speed corrects itself. If it doesn't then see what it does in reverse play mode.
 
I removed the one bad spark killer that smoked and melted but haven't tried removing them all, (or lifting one leg on all.) That was my next thing to do. I will do that next.
Thanks to everyone for all their suggestions and help.
I will advise. Didn't even think of trying reverse mode.
 
i wondered about reverse mode too but presumed it would have been tried .. will maybe rule some things out whatever the outcome .
 
BINGO!!!!! We did it!! (Notice how I said we - couldn't have done this myself.....) Removing the 4 spark killers did the trick. Both high and low speeds are now right on and sound great. Thanks to all.....
Now, moving on. Can anyone recommend a source for the film version of those spark killers? Do they really have to be 400V?
 
Replace all four with the RC snubber network that dnash linked you to in post 13, simple as that. Yes they have to be rated at 400v or above and they need to have the same impedance and mfd value as your existing devices.
 
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