broke my tascam 464 by switching tapespeed while playing

[jasonkick]

Hey guys hoping to fix this on my own and wondered if anyone has an idea of what went wrong here...

I was playing with the pitch control of my Tascam 464 (4-track cassette, very similar to the 424), moving it around pretty fast (tracking a synth and needed some bend), accidentally hit the tape speed switch while it was recording and suddenly it seems to have caused the playhead to not engage. No matter what tape I put in, when I press play, the play button will light up green, the head will rise up, and then it will promptly disengage (the light then turns off).

Rewind and fast forward are fine, and when there's no tape in and i put my fingers on the upper mechanisms (not sure what they're called) to "trick" the machine into thinking a tape is in, then the play function will start running as usual.

And yes, it says in the manual not to switch speeds while the tape is running, but it says it only has these consequences: resets tape counter, cancels out operation modes and memory points, none of that has anything to do with this.

Any idea what happened? Something similar must have happened to someone at one point.

Thanks, love Tape Op and the Message Board, have been a big reader for years.

Jason Kick
Audio Engineer
San Francisco

[themagicmanmdt]

switching speeds like that for a circuit might have had a sizable spark or sudden large current draw going on.

is the rubber roller moving towards the capstan?

does the capstan spin?

[jasonkick]

thanks for the reply.

yes the capstan spins, the play function is just shutting off a second after i press it.

i contacted tascam and they can't provide advice over the phone, so i may have to send it in if no one hear has any ideas of what to be looking for.

[jasonkick]

"no one here"

[themagicmanmdt]

so, here's what i'd start thinking about:

the play function is connected to a logic system, which might be anything from engaging a solenoid/relay to a circuit that is engaged with a voltage or transistor (or IC chip) then turned off by the stop circuit.

the next steps would be:

is a full schematic available? do you have the manual? does it have a schematic as well as a PCB layout of the parts?

if so, then it's starting to look at the way the area that the logic function works. sometimes, it's obvious that a cap is blown on the board, and can be swapped out. usually, a bad cap also means that a transistor went with it. that can also mean that the cap failed due to a resistor drifting out of spec.

so, yeah, it looks like it's a tascam call. an independent tech could look at it, but it would also involve them really spending time learning the machine's logic (litterally!). it might be simple, though!

unless you've had some XP with circuit tracing, electronics theory and puzzles, i'd say send it to tascam, or find people who work on tape machines, analog gear, or maybe synths... that's the kind of mindset to look for in a tech for this...

hope i shed a light...