Akai MG1214 Technical problem

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Stef7

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Hi all,

my MG1214 (bought used two days ago - for own usage) doesn´t record anything on any track (whether CH1-12 nor sync or Controltrack), while the playback works without any problems (even the Controltrack) .Technical seen it -must- be impossible that the entire recording head is defect, since each recording Track has -so seen- it´s own connector. When i set the tracks from "PB"to "REC", i´m also able to hear a "click" from the relay of the concerning track. The fuses right-handed at the device are all ok, the mixer also works. Noone also screwed on the PB/REC-Head.

So i think there are only two possible defects: The recording head needs it´s own voltage source (which i don´t believe) -or- the tape itself is defect. Therefore I am momentarily somewhat helpless.....

It would be great, if someone would be so nice and send me by email the Service manual for the 1214 - i´m not able to order it here in Germany, since no Akai support exist here :(


Many thanks!

Greetings

Stef
 
Does the cassette have a record safety tab, (like a consumer VHS tape cassette), that is in the safe position?

Check that out and let us know.

Cheers! :)
 
Nop, unfortunaly not. The Machine itself starts recording, but it doesn´t record anything. Sometimes, but really only -sometimes- i hear with max. Track/Master Volume a very very quiet, distorted output from -my- previous recording. So i think someone must have screwed on the Azimuth. The MG1214 has two screws for that, once the "Control" Azimuth for the Clock signal, second a screw for the Playback -and- the Record-head, but the Record head doesn´t move when i tweak on the screw, only the playback-head.

So something must be wrong with the position of the record head, but how i should correct it, if the record head doesn´t move?

-Or- the overall mechanic is bent, sometimes the tape has transport problems when i perform rewind/fast forward. But if this has a big influence on the tape operation, is the big question....

The best thing would be to buy a complete new Tape-Drive, but 1) from where, 2) the price would be way too high....

Greetings

Stef
 
If the record head doesn't move, then how could the recording azimuth be off? In essence, it can't. Nor would I suspect head alignment as the prime suspect.

I'd look at track arming and mixer assignments first to make sure I was operating the unit correctly, 110% before I suspected machine error.

If you are absolutely sure it is not a case of operator error, (no offense intended here), then I might look at things that are common to all of the recording channels like master bias oscillator adjustments and internal faulty wiring harnesses that hold connection for all 12 channels.

If the heads were out, there would still be more then what you described or at least stuff shifting one channel up or down on the headstack...IE; recorded on track 2 but plays back on 1 or 3.

Good luck.

Cheers! :)
 
This wouldn't hurt either!

A trick to go around the problem of finding new tape is to open up the shell of an existing cassette and load in some fresh Quantegy 456 onto the spools and close the casing back up...you're NEVER going to find fresh, new, ready to go tapes for that unit so you must be inventive. :cool:

Cheers! :)
 
The Ghost of FM said:
I might look at things that are common to all of the recording channels like master bias oscillator adjustments and internal faulty wiring harnesses that hold connection for all 12 channels.
Click to expand...
Funny you should mention bias oscillator, I had a similar issue with my old Akai reel to reel.

Would pay to check the signal going to the record head with an oscilloscope and make sure there's a bias signal getting through - if not then check relays etc. You'll need a circuit diagram.
 
Hi,

i´m absolutely sure that i don´t made any mistake while setup , according to the 1214-Manual (available at Akaipro.com) it works -more or less- like my old Yamaha MT8-X: Choose the record Track (12), switch the mixer input (Ch12) to "line", perform recording, rewind, set the mixer input source (ch12) to "track", perform playback. I´ve also tried it with the "bus"-settings, but it also doesn´t help.....

We´ll see....the good thing on the 1214 is that it can record up to 14 Tracks simultaneously, never had before a recorder which was able to do that and i -strongly- hope that i´ll get it back working; recording with the MT8-X was the hell! Sync-Track here, ping-pong there andandand.....

About the Casettes itself: I believe that it could also work, if i use the tape of a VHS-Casette...

Many thanks!

Stef
 
About the Casettes itself: I believe that it could also work, if i use the tape of a VHS-Casette...
Click to expand...
Nope! ;)

Wrong formulation for audio.

You must use an audio tape formulation which has the correct thickness, bias requirements and oxide coating formulations.

Cheers! :)
 
Oki ;-)

But now i have a almost bigger problem:

First it happened that the reel of the tape transport (which moves the tape ifself over the heads) started to move upwards and didn´t stop automatically. All three switches, which control the transport itself, switched correctly. After a while the entire drive didn´t work anymore, so i think that the motor driver itself or the entire controller board (mounted right-handed on the drive) is defect. The control buttons doesnt work anymore , nor play/rew/ff/rec etc, it is simply -death-.

I have -no- chance to figure out what´s the problem without the schematics, i even cannot test the Motor driver, cause no datasheet exist of it....

Stef
 
...

Verify the fuses again, & verify the heads are spotlessly clean.;)
 
Hi,

All fuses measured, they´re all ok....

Without schematics/circuit diagram: No chance! The Motor driver IC (which i believe that it -is- defect) is a UPC1043C (not any longer produced by NEC).

I don´t know -what- control performs -which- function, i don´t know any voltages...

Greetings

Stef
 
Hi,

no, it wasn´t this IC, i´ve found the error: Two BA6109 Motor drivers, once for the reel, second for the loading motor.

But, as always, the next component is defect: The main processor called HD6805V1P, controls nearly everything, no matter why this happened (got very hot after a while). Proably i will order it over Virtual Sounds Technology, Pasadena.....so i´m not able to repair it, as long this part isn´t replaced...

But i would still need a Service manual / Circuit diagram-doesn´t anyone have it??

Many thanks

Stef
 
Tapes and stuff

HI how goes it with the mg1214 ?

I have a functioning one in my studio but no tapes any ideas? Are I believe that you can get them but where from I don't know!!!

When I ordered it the couriers lost the box with the tapes and power lead.

anyway if you need any voltages / inages of circuit let me know.


Russ :cool:
 
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