Soundcraft SCM 381-8 tape deck problems

[Rob Flinn]

Hello folks,  I was lucky enough to be given a Soundcraft SCM 381-8 tape deck recently that had been in storage.  I haven't plugged it into anything yet but the machine is in remarkably good condition, with very good heads, but I have a couple of issues.

The machine plays, fast forward, & rewinds with no problems.  I can arm 7 of the tracks to record but track 6 won't arm.    When I actually try to put the machine into record the take up reel doesn't operate & the machine tries to spool the tap off on to the floor.  This is odd because it's ok in playback.  I have service manuals , but despite being an oldie I have never had to fix a tape deck before, so I was hoping someone might have some experience that could put me on the scent.  Thanks.

 

[abbey road d enfer]

Hello folks,  I was lucky enough to be given a Soundcraft SCM 381-8 tape deck recently that had been in storage.  I haven't plugged it into anything yet but the machine is in remarkably good condition, with very good heads, but I have a couple of issues.

The machine plays, fast forward, & rewinds with no problems.  I can arm 7 of the tracks to record but track 6 won't arm.    When I actually try to put the machine into record the take up reel doesn't operate & the machine tries to spool the tap off on to the floor.  This is odd because it's ok in playback.  I have service manuals , but despite being an oldie I have never had to fix a tape deck before, so I was hoping someone might have some experience that could put me on the scent.  Thanks.

You definitely need to study the logic board. Lots and lots of CMOS gates.
IIRC the logic board is quite accessible (I'm not 100% sure, I've only worked on the 2" machines).
You need to unload the tape and immobilize the two tape sensors, as if tape was present, then you can check the voltages.
First check the logic board for debris, most of them had no solder resist.

 

[Rob Flinn]

Thanks Abbey.

There are 3 boards that do the logic.  They are stacked next to each in the remote, which is basically the front panel of the tape deck mounted in an external box and connected with a 25 pin Dsub cable.  The cable is definitely ok becuase I tested it with my Palladin tester.

I think the channel boards are the same as the 2" but the rest of it is different boards.

 

[abbey road d enfer]

Thanks Abbey.

There are 3 boards that do the logic.  They are stacked next to each in the remote, which is basically the front panel of the tape deck mounted in an external box and connected with a 25 pin Dsub cable.  The cable is definitely ok becuase I tested it with my Palladin tester.

I think the channel boards are the same as the 2" but the rest of it is different boards.

Quite different indeed. Do you have easy access to the boards for probing?

 

[Rob Flinn]

Quite different indeed. Do you have easy access to the boards for probing?

Yes it is possible to probe the boards.

I did some RTFMing last night & I think I may not have threaded the tape the right side of the take up spool sensor (palms forehead).    I need to test it again with the the tape on the right place & hopefully this will sort out the issue of it spooling the tape on to the floor.  Weird it didn't do it in playback though.

 

[radardoug]

You say you were lucky to be given this deck. Thats not luck, thats masochism! If you have a boat, you now have the perfect boat anchor!

 

[Rob Flinn]

You say you were lucky to be given this deck. Thats not luck, thats masochism! If you have a boat, you now have the perfect boat anchor!

Haha.  Would you care to eleborate on it's bad points for reference Doug ?

 

[radardoug]

The Soundcrafts were never great decks and I think they were out of their depth in building them. So lots of problems with the mechanical design and the electronics.

 

[Rob Flinn]

The Soundcrafts were never great decks and I think they were out of their depth in building them. So lots of problems with the mechanical design and the electronics.

Yes, I get they were more of a "budget" option.  I was just going to get this going to give myself a bit more experience before I tackle my Telefunken M15a.  I was also given this machine but it needs a lot more work than the Soundcraft which is in very good condition.

 

[bill_face]

Hey. Did you get this going? I'm after one of these (or a similarly sized 1" 8 track machine)

 

[Rob Flinn]

Hey. Did you get this going? I'm after one of these (or a similarly sized 1" 8 track machine)

No, I never found the time. It's still on the shelf.