How to open my Tascam 38

  • Thread starter Thread starter WarmJetGuitar
  • Start date Start date
WarmJetGuitar said:
The old belt was kind of intact but way too loose and inproperly placed so I just cut it. The new belt looks well placed - I could see where the old one used to be and put the new belt there.
I don't know how to start the machine with the cover off because the control pannel is connected with a pretty short cable. I better figure out some way of checking that when I get home - sounds like a good idea.
Click to expand...

Ah yes, sorry. I was thinking of the TSR-8 which has the main cover separate from the control panel.

If you can power the machine on, you can test the capstan just by lifting the right-hand tension roller and making sure the capstan shaft turns.

Other possible causes include the pinch roller not gripping properly - though I think you ruled that out, severe back-tension problems (if the tension is loose enough for the roller to go down, the capstan motor will shut off) or possibly the tach roller if the 38 does use one for motion-sensing. I'll have to check the '32 schematics again at home and see if I can figure out how that works.
 
You should be able to leave the transport attached by just setting the cover gently to the right side of the machine. Then you can use the transport buttons. Or you could pick up a Tascam RC-71 remote somewhere. But as stated, you should see the capstan turn if you lift the right tension arm or press the edit button.
 
You dont take that motor out to replace that belt. Its been a couple of years since I did it but its a real easy thing to do by pulling the head block.
 
Okay, as an addendum to what I was saying before, if the 38 is like the model 32, it won't have a tach roller - tape motion sensing is done by a similar mechanism attached to the right reel motor shaft.
Just as a test, I'd make sure that the tape counter does count when you go into fast wind - if it DOESN'T, that could indicate a problem and would probably cause it to shut off or misbehave in PLAY mode, even if the capstan system was okay.
 
The counter is doing fine when going FF or backwards.
I did what FStrat said and put on a tape - it just says "clonck" and nothing happens. None of the capstain wheels is going anywhere, neither when pressing play or when messing with the tension arm. Is the main capstain motor dead or is there still things I need to check?
When I press play without any tape on the machine it starts running but still without any action from the capstain wheels.
 
You should be able to see the capstan turning. With the cover off, just press the Edit button in (or right tension arm up). The capstan should start turning. If its not turning and the belt is installed properly, then maybe its the motor or a circuit board.
 
Capstain ain't going anywhere (regardless of edit mode, manually held tension arms, etc.) - dead motor? Is there any chance the motor just need some lubrication?
The pinch roller tension seems a bit too tight, the right reel is much harder to move by hand when the roller is enabled so I better get the spring scale mentioned in the manual. However this shouldn't affect if the motor capstain is running in edit mode? Does the height on the capstain wheels affect if it can run?

Will it make sense to mess around with the PCB cables? Just unplugging and putting them back in place?
I'm considering taking it to a pro repair guy when I'm not short of cash - something that happens way too rarely :o
Sorry to bother you so much with all these questions, I'm just sick of dubbing vocals digitally and having to mix bass and drums in order to get stereo drums on the four track that we use. I must warn you that if this project fails a lot of questions about pinging is about to occur :p
 
Blown fuse, maybe?

Hey WarmJetGuitar...

I would check the fuses again and make sure none are blown. I *think* that the capstan motor may be on it's own fuse, and if that fuse is blown, most of the deck will seem fine, but the capstan won't move. I blew a fuse while poking around in my 38 and had the same symptoms.

Check the fuses by taking them out and testing them with a multimeter set on "Ω" resistance (Ohms). A good fuse should read a very low number of Ohms or a fraction of an Ohm, like 0.125 Ohms. A bad fuse will read "infinity", "OL" or something like that, depending on your meter. This means "no connection" or infinite resistance. That's the one you'll want to replace.

It's worth a try... Hopefully it'll be something simple.

-Tom.
 
Hi Tom!
Thanks, it sounds like something I better check. Have to find a multimeter, but that's the smallest problem. Next challenge is to locate the fuse without wrecking the recorder in the process. Any suggestions?
Thanks again for all your help - forgive me for my noobness.
 
IIRC, the fuse board is at the top, just above one of the reel motors.
 
Yep... You'll need to take the back panel off of the deck in order to get at the fuses. Actually, i think i took the back, front and top-sides off when i was working on my machine. It was just easier to get at everything that way.

I think i have a bunch of photos from when i was working on my machine, that show how to get at the fuses. Let me dig around for them tonight after work, and i'll post them.

-Tom.
 
After removing the back panel and unscrewing a board I can see ten fuses.
The manual mentions 17 fuses, but only ten with voltage strength (250V) and ref. no.
Anyone knows which one is for the capstain? Or do I just have to check them one by one with the multimeter?
The easiest would be if I knew which one is for the capstain as fuses is cheap and easy to get.
 
WarmJetGuitar said:
After removing the back panel and unscrewing a board I can see ten fuses.
The manual mentions 17 fuses, but only ten with voltage strength (250V) and ref. no.
Anyone knows which one is for the capstain? Or do I just have to check them one by one with the multimeter?
The easiest would be if I knew which one is for the capstain as fuses is cheap and easy to get.
Click to expand...

If I'm reading the schematics right, it's probably F505. But I'd check them all anyway if I were you.
 
I guess you do! Thanks James. It is easier for me to get a fuse than a multimeter so I'll try and replace it tomorrow and see what happens.
 
Just took a look at the schematic... Make sure you test F505, F506 and F502. They all seem to provide power to the capstan motor. Here are all of the fuse values listed in the manual:

Fuse: USA, Canada / Europe, UK, Aus. - Volts
-------------------------------------------------------------
F505: 3A / T3.15A - 250V
F506: 2A / T2A - 250V
F501-F504: 2A / T2A - 250V
F507-F508: 7A / T5A - 250V
F509-F510: 1A / T1A - 250V

Let us know how it goes!

-Tom.
 
All the fuses is fine - which points to the capstain motor gone bad, right?
So the guy in the electronics shop who is a tape head too (he even knew the secret handshake :D) and is always very helpfull offered me his 38 as parts, the electronic parts is gone which is why he'd given up fixing it but he is absolutely sure that the capstain is in good working order. He's asking 59£/67€/95$ for it - is that a good price?
I think it sounds very reasonable if the heads is working too.

So my questions is:

Anything else to check before buying a capstain? Could it by any means be related to the electronics? Just to summarize to new readers it says "clonck" and the pinch roller goes up when pressing play.

Is it hard to change a capstain motor? As far as I can tell it is the big round thing just behind the pinch roller.

Something that just crossed my mind: when I was messing with the recorder earlier the very small plastic things on the tension wheels disappeared in the process. What role do they play?
 
If it's not the motor, it may possibly be a problem with the motor getting power, e.g. a connection issue. Heck, it may even be the microswitch on the tension arm. If the motor is getting power but still isn't running it might perhaps be a drive transistor.

I've not needed to replace a capstan motor yet, so I'm not sure how hard it is. I think it's just bolted to the chassis. It would be nice if you could put a voltmeter on it and see if it is getting power or not - either way, a parts machine would be very useful if one is being offered.
 
The forum didn't like me posting this for some reason, so I'll try again.

If it's not the motor, it may possibly be a problem with the motor getting power, e.g. a connection issue. Heck, it may even be the microswitch on the tension arm. If the motor is getting power but still isn't running it might perhaps be a drive transistor.

I've not needed to replace a capstan motor yet, so I'm not sure how hard it is. I think it's just bolted to the chassis. It would be nice if you could put a voltmeter on it and see if it is getting power or not - either way, a parts machine would be very useful if one is being offered.
 
Yeah, could save me some money and trouble. I think the multimeter I bought should be able to do this. Now I just need to figure how to avoid frying myself or the machine in the process :)
 
WarmJetGuitar said:
Yeah, could save me some money and trouble. I think the multimeter I bought should be able to do this. Now I just need to figure how to avoid frying myself or the machine in the process :)
Click to expand...

The motors are all 24v, you'd have to try quite hard to kill yourself with that. Killing the machine is a little more likely, though when I shorted the erase head on my B77, it blew the internal fuse and then carried on happily once that had been replaced.

That said, I would strongly recommend if you work on the machine while it's running, that you be sure to have it plugged into the mixing desk as it may need this for grounding. On the TSR-8, I found that if the outputs aren't connected, the chassis may have half mains voltage (!). All of mine did this so it seems to be the way they're designed. I haven't tried it with my '32 though.

Regarding the measurements, a lot will depend on how easy access is to the terminals on the motor. On the PCB side they're likely to be inside connectors which will make things a pain.
 
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