Is the AKAI MG1212 and 1214 worth buying today?

Holy Cow deslog, those pictures make me happy. So cool to see the photos. I just ordered a 14d and it is awaiting for me in Nebraska. I will be able to check it out in 2 weeks. On Eject arm, yes, I imagine re-bending would work. It is aluminum which is a real "sticky" metal. If you want to take the easy way out, just lube the bottom and "help" the loading system to move smoothly with your hand when you use it. If you do use heat, i would personally think a heat gun, not a flame, would work best, just slowly working up to temp. Even a hair dryer. As for my recent work, I managed to burn up a display, which is NOT LED or incandescent. I think its fluorescent. Look super close at big display. It has wires like a toaster and honeycomb shape stuff behind it. I also burnt up the driver for the loading mechanism. Thankfully it is only a 6 dollar IC online. It is an actual motor driver on "system control board" with a heatsink. My fuse for the high voltage kept burning up (30v ithink) so i assumed the problem was on a 30 volt line. However since the motor driver IC works on a different voltage, I assumed that was not the issue. In hindsight, this IC was DRIVING the 30v circuit, causing it to go haywire and burn fuse (from what I can tell.
Currently, I have been building stand alone housings for tape mechanisms. Reason being, it seems an abusive situation to remove these things and back and forth 10x. This way I can observe and use in plain view. I have extension cords made and have operated this remotely, but am still in process of working all this out. I recently, FINALLY got the wave form I was looking for on my oscilloscope. Has to do with the erase coil. After I got the waveform, everything went South, as noted above. I will try to post specifics on another thread. Essentially, by swapping boards between machines, I found an issue with the 100khz oscillator, and the beauty of having multiple machines, is I was able to see that another machine suffered the same issue.
Rob
 
Wow. Your going to a lot of trouble and very patient. What is your end goal? Are you just enjoying the process of discovering how it all works and are you planning to record on it?

Dave from VST is an amazing resource. I have asked him many technical questions regarding different things to do with the Akai's and he has always been very supportive.
 
Hmm. Perhaps this is the thread I was looking for. Sweetbeats and I were trying to figure out my recording issue. Turns out that I found an issue which may solve this. As you said Sweetbeats, the oscillator could be the issue. So recently, by swapping boards from different machines, I found that a record/playback board from one of the machines was giving proper wave forms on the oscilloscope. This board was from the parts machine I got from you Sweetbeats. It is in poor shape with all sorts of corroded components, but for some reason, the "good" machine I got from you, as well as another I picked up afterward, had the exact same recording problem, while the parts machine was the only one with a proper functioning rec/pb board (unbeknowst to me at the time) The "good machines" would only give a very faint signal to tape when hit super hard. You were right. Although I have yet to record well to tape, the scope is showing progress. Turns out that two of the better looking machines, were not producing proper waveforms due to some problems surrounding "fusible resistors" number FR1 abd FR2 on rec/pb board. I am not a tech, so I dont know much about schematics, but there it is. Right near an IC that seems to be spitting out the 100khz wave for recording bias, there are the fusible resistors. One machine has both resistors blown, plus a diode plus maybe more. The other machine has the same issue surrounding this part of the board. I think only one resistor is blown here.
While there are variations in machines from year to year, my theory is that if I simply use an ohm meter and compare componets from one board to the next, the bad components cant hide forever. Its my only choice, as I am only learning about transistors and whatnot as I go. Some componetns are readily available on ebay or mouser, while some transistors are requiring me to find substitutes. If you would have gotten your hands in the mg1212 you could have done this in your sleep Sweetbeats. Anyone have secematics for the MG14d? or mg1214?
Rob
 
Yes. I just started recording on the one that partially works. I want to get 2 or 3 going so if I am in the middle of writing, I can do it non-stop. Thanks for the reminder. I love music first. The end goal, is to make a few good songs, rock/ metal. Not a crap load of filler, just some real inspiring stuff. Im 45 now, and all my music from the past, like when i was 25, the stuff done on an akai mg614 sounds very magical. The MG1212 will pry sound more polished, but hopefully retain whatever the mg614 had. I would hit the tape so hard. I love good music. Trouble is, I am not a good musician, bad tone ears etc......I CAN write and, given enough takes, perform well too. Recording is my only option to make good music. I saw guitarist Eric Gales say, something like, the notes your playing are only half, the other half is the sound (tone) it makes. If I can take hundreds of hours, soldering, singing and so forth, and have some kids mind be blown away, then I am only returning the favor that other musicians and producers gave to me.
Cool to hear about Dave. I need to meet that guy someday. I wonder if he would let me sit in and watch while he did a repair.
Rob
 
You could always ask him. He can only say no at the worst or you could pay him for his time and ask him anything you like.
 
I am looking for a capstan motor for my MG1214. I assume the bushings wore out so the spindle doesn't turn. Anyone with parts?
 
I believe this thing not only requires power, also some circuitry that regulates power because motor must turn at an exact speed. A feedback that tells motor to speed up or slow down.
 
It physically wont turn when you try to crank shaft by hand? Its completely seized? There are plenty of places that work on motors. You could start with an electronics shop.....or even a place that repairs motors for bigger stuff could recommend some place.
 
It physically wont turn when you try to crank shaft by hand? Its completely seized? There are plenty of places that work on motors. You could start with an electronics shop.....or even a place that repairs motors for bigger stuff could recommend some place.
Thanks ! I will do a deeper dive into it.
 
Alright. I recently got back into my machines. Heres what I know. Out of my three power supplies, only one works. One of them shows the full volts sitting on my table with a meter,, like around 38v, but when it is installed in machine and the play button is depressed, lights go dim and voltage drops to 18v. A good working power supply loses about 1.5 volts when play button is hit. This is for the 35v part of power supply i am refering to. So, as I am trying to fix these power supplies, I noticed that they are tucked away under a board and looks to me like it would trap too much heat there. So, I am going to install fans inside. The first one I did is at the bottom where you can remove a cover to access belt. I made a new cover, put a fan in it, then lit some matches and watched the smoke flow through power supply area. The way I did mine, I can no longer set my machine flat on a table because the fan sticks out. The ones I am doing next will be in the machine. Will it be too noisy? Doesnt really matter, as I can turn on and off as needed,

So I got my new MG14D recently. Thing looks like new. I put a shirt over it to keep dust out, left it on and when I came back a few hours later, It was so freakin hot. I felt bad and stupid, but I learned the massive amount of heat that can be generated even at idle. Thats my new focus: Cooling. So the MG14D looks SOOOOOOO much different inside. Massive heatsinks, and just so much more to it than I would expect. Definately not simply cutting the mixer section off an MG1212. More recording cards etc......The 14D is going to be great. I will be able to take tapes from the 1212, and play them in 14D. The 14D has all direct outs!

Also, I recently fried something on my SYSTEM CONTROL 2 board. It got super hot when I was working on it. Turns out the two motor controllers on that board burnt up. There is one with a heatsink and one without. I bought new ones, like BA6108 or something like that, and they work! I got a temperature gun, and checked the temps at first start up. Heres whats cool........When play was depressed, you could watch the temp rise in the chip (one without heatsink) and fall when stop was pushed. These chips simply do stuff like hit the brakes when stop is pushed, and just allow better motor function.

So thats where I am at. The power supplies, from heat or that dang battery, are a big problem on these machines. Secondly, just an all around good idea in my opinion, running better cooling with airflow or upgraded heatsinks should help.

Also, because too much soldering can mess up the boards, I installed transistor sockets, I can now rapidly replace burnt transistors and zener diodes. BIG help when trouble shooting.

The picture above where the transport is out of machine works really well. I have three working transports that can be swapped in and out in like a minute. All the springs and guts can be viewed as well. It was pretty simple to do and works well. Looks like crud, but personally I am fine with it.
 
One more thing.........I finished two songs and put them on a cassette. Took them out to my wifes car, and man the bass was ALL THERE. Flipping back and forth between the radio and my tape had me convinced that these machines are indeed pretty frickin cool.
 
Hi, I'm starting a restoration of an MG 1214, looking for the precise output voltages to be read from the trafo, could anyone share the service manual?
 
Yeah. I have schematics for mg1212. I am also picking up an mg1214 in the next couple months. I'm a little busy today. I have three power supplies on my bench and have just recapped one. All mg1212s. In fact, I need a little help with power supply schematics myself.
 
I am an electrical novice. I know on schematics it says the 35 volt output. ......but by the transistor it is supposed to read like 39 volts. Not sure why. On one of my working machines, this voltagedrops only around a volt when play is engaged. On one of my bad power supplies, this voltage drops considerably when tape is rolling
 
Thanks, I'm an amateur too. I'm getting 11.5 - 27 - 6.7. That reads a bit low, might need a rebuild, caps are all good although a bit tired.

Atm based in Europe. Would be awesome to have your schems.
 
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