Help a noob - Otari MX5050 8 Track....Track 1 dying

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rlcrosby

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Hi, this is my 1st post, I am pretty new to recording and in need of guidance.

I have an Otari 8 Track MX5050 MKIII 1/2 inch machine. Track 1 is cutting in and out. I have been able to record, but very little, if anything, is audible on playback. Nothing shows up on the VU. If I quickly switch between repro and sel-rep, audio comes in for a second and then fades out right away. Track 1 has played maybe 1 out of the last 5 times I have tried it.

The machine was recently de-magnetized and calibrated. During the de-mag, the wand briefly touched one of the heads. Could that have caused this? How do I go about trouble shooting?

Thanks for your help!
 
Have you tried cleaning the eraser head? Just put a little head cleaner on a cotton swab and rub it over the head. I have a can from like, the 90's that my daddy gave me, it's some tascam stuff, so I don't know where abouts you'd find that stuff now-a-days. Anyways, if some nasty looking black stuff comes off then the head was just really dirty. I don't think the wand on the de-magnetizer bumping the head would do anything. I bump the heads all the time while de-magin. But this is advice coming from another noob so, I could be wrong. I also have a fostex machine. :x
 
yeah, i clean the heads pretty diligently. it was suggested that i try cleaning the switches. do you know what i should use for that?
 
well, head cleaner is like, a non-water base alcohol cleaning solution i think... So I'm pretty sure (but still not totally sure) that any non-water base solution should work. But don't blame me if your deck stops working, again I'm a noob too, maybe even more so. :x
 
Hey guys - try to find contact cleaner or preferaby deoxit to clean switches (I believe deoxit has a lubricant).

Also - be careful when demagging! Bumping the heads (if you demag is not protected by plastic) can permanently magnetize the heads...

Good luck!
 
I have an Otari 8 Track MX5050 MKIII 1/2 inch machine. Track 1 is cutting in and out. I have been able to record, but very little, if anything, is audible on playback. Nothing shows up on the VU. If I quickly switch between repro and sel-rep, audio comes in for a second and then fades out right away. Track 1 has played maybe 1 out of the last 5 times I have tried it.

Sounds like a relay issue...

The machine was recently de-magnetized and calibrated. During the de-mag, the wand briefly touched one of the heads. Could that have caused this? How do I go about trouble shooting?

What kind of wand and did it have a protected tip? If the tip isn't protected and it touched the head it could scratch...if it has a prtected tip it is extremely unlikely that it could scratch and therefore it wouldn't be a cause to consider.

Have you tried cleaning the eraser head? Just put a little head cleaner on a cotton swab and rub it over the head. I have a can from like, the 90's that my daddy gave me, it's some tascam stuff, so I don't know where abouts you'd find that stuff now-a-days. Anyways, if some nasty looking black stuff comes off then the head was just really dirty.

When cleaning heads you want to clean ALL the headstacks, not just the erase head. Cotton swabs are fine but 100% cottom makeup remover pads are much more effective. New head cleaner can be found. MG Chemical makes an audio and video head cleaner, or easier yet is isopropyl alcohol in at least 91% purity. 99% is preferred but hard to find. Good quality denatured alcohol is another worthy alternative.

yeah, i clean the heads pretty diligently. it was suggested that i try cleaning the switches. do you know what i should use for that?

DeoxIT D5. That's the one without lubricant for metal-to-metal contacts. DeoxIT D100 is another good one to know about if the contacts are really scungy.

Hey guys - try to find contact cleaner or preferaby deoxit to clean switches (I believe deoxit has a lubricant).

No, only certain types like the DeoxIT FaderLube F5 have a lubricant. D5 or D100 are for metal-to-metal contacts in switches or connectors.

Also - be careful when demagging! Bumping the heads (if you demag is not protected by plastic) can permanently magnetize the heads...

No. That is false. Bumping the heads has nothing to do with megnetizing. The risk is that bumping the heads with a non-protected wand tip could scratch a head. Now, shutting the demag unit off when it is close to the headstacks? THAT can permanently megnetize the heads.

Another suggestion is to re-seat the amp cards in your 5050, but honestly I'd look to a relay problem. May be time to replace them. The relays on the amp cards handle source switching on the output side (sync or repro or input) and also engage the record amp section. If the contacts are tarnished or if the reeds are weak etc. etc. they won't switch and pass signal reliably or at all.
 
i don't know if the wand had a plastic tip. didn't know to look for it....but, my friend is very careful and superstitious about demagging, so i think it's probably safe to say that there was something covering the wand. he didn't seem worried at all when it happened.

i've been cleaning the heads with q tips and denatured alcohol. i'll get some makeup remover pads...and some deoxit d5.

how do i go about checking the relays?

thanks!
 
Well, you can't really "check" the relays, at least there isn't a straight-forward method of which I'm aware. You could check to see if the intermittent signal is present at the pertinent output of the relay but we're talking relatively advanced diagnostic stuff here (not sure what your experience/comfort level is). You'd need an extender card to be able to access the relay terminals on the amp card while the machine is operating and be able to read the schematics to identify which terminal of which relay you would want to test.

The behavior sounds like a faulty relay though and they are cheap and if you are into soldering stuff it is definitely a DIY-able thing.

BUT...you want to make sure the heads are all nice and clean and also make sure that the tape is running smoothly in the tape path and that the entire tape path is clean.

Try this too: with the tape running and the problem ocurring, does it make any difference if you gently and slightly push the tape down in the headblock (closer to the machine's face) or slightly lift it up (away from the machine's face)?
 
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