Tech question about my 388

  • Thread starter Thread starter Sickstring
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Sickstring

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Hi all,

I have a 388 that hasn't been used for tracking in several years but has always performed admirably. All tracks play back fine save for occasional dropouts on a few channels where I have to tap the pan pot to get the signal back. I have recently gone over the pots and switches with some deoxit to rectify the problem, albeit with limited success.

Last night I tried recording and I am not having any luck with tracks 3 and 7. I have spent some time on this message board and gotten some great tips but I am stumped with this problem. Could it be the audio cards even though tracks 4 and 8 still record perfectly? I thought it might be the record function switches, but even if I bypass those and listen with the monitor button depressed I still get no signal or response from the VU meters on channels 3 and 7.

I would have just popped the cards out and reseated them to be sure but I have read that it is possible to cause more problems if it is not done correctly. I'm nervous about doing it if it isn't absoloutly necessary.

Any other suggestions?

Thanks in advance!

scott
 
Sickstring said:
Hi all,

I have a 388 that hasn't been used for tracking in several years but has always performed admirably. All tracks play back fine save for occasional dropouts on a few channels where I have to tap the pan pot to get the signal back. I have recently gone over the pots and switches with some deoxit to rectify the problem, albeit with limited success.

Last night I tried recording and I am not having any luck with tracks 3 and 7. I have spent some time on this message board and gotten some great tips but I am stumped with this problem. Could it be the audio cards even though tracks 4 and 8 still record perfectly? I thought it might be the record function switches, but even if I bypass those and listen with the monitor button depressed I still get no signal or response from the VU meters on channels 3 and 7.

I would have just popped the cards out and reseated them to be sure but I have read that it is possible to cause more problems if it is not done correctly. I'm nervous about doing it if it isn't absoloutly necessary.

Any other suggestions?

Thanks in advance!

scott
Click to expand...

Over time, as you noticed, pots and other connections oxidize. The card edge connections do also. The best thing to do is to pop the cards one at a time and use a pencil eraser and a good de-oxidizer spray to clean all connections. Re-seat the cards and see what happens. Clean the heads only in the direction that the tape travels and demagnatize them. Allowing any tape deck to sit for too long can make it a real bear to get it running again (the worst of which is the destruction of the motors over time). The motors bearings can develop flat spots if allowed to sit for too long as the weight of the internals slowly compresses the bearing races.

Good Luck.
 
Quantagee,

Thanks for the reply. I guess I hadn't considered oxidation on the cards. That sounds like a good place to start. Fortunately, I have kept the machine running fairly regularly just listening back to old tapes and such, I just haven't recorded with it in awhile. This is just dumb luck on my part, 'cause I didn't know it was bad to leave these machines sitting unused for long periods.

Thanks again!

scott
 
well i think when you record on those channels you must select the red button and pan the signal left...did you do that?
 
Pulling the cards didn't help

Mikey, I did go through the proper setup for recording. As I mentioned, I get signals on every channel except 3 and 7. That is why I am so perplexed. I pulled the cards and put some deoxit in the slots, although the pins were still shiny, but that didn't seem to help.

Any suggestions pertaining to the logical place to look in the signal path? There are no loose switches or wobbly faders that I can tell. I'll admit I don't have the manual and I'm sure that ain't helpin' things. Is it wise to pop the panel that houses the channel strips to take a look inside?

Thanks again in advance for your replies.

scott
 
Sickstring said:
Mikey, I did go through the proper setup for recording. As I mentioned, I get signals on every channel except 3 and 7. That is why I am so perplexed. I pulled the cards and put some deoxit in the slots, although the pins were still shiny, but that didn't seem to help.

Any suggestions pertaining to the logical place to look in the signal path? There are no loose switches or wobbly faders that I can tell. I'll admit I don't have the manual and I'm sure that ain't helpin' things. Is it wise to pop the panel that houses the channel strips to take a look inside?

Thanks again in advance for your replies.

scott
Click to expand...


It still sounds like it is electronic in nature. Tracks 3 & 7 are not both outside tracks. If it were tracks 1 & 8, I would point to the heads. But, stranger things have happened.

If you recorded fine a long time ago, and played tapes up until now, then the only thing that it could be, if not electronics, is extremely dirty heads, or extremely worn heads. Usually, worn heads don't "go away" like a switch. They degrade slowly. But, if you played tapes for a long time, and never recorded, you would never know the heads were degrading. Time for a head check I think. The record head is in the same path as the play head and subject to the same wear. You could pull the headstack and send it to JRF for them to see if the heads are bad (or need a re-lap). How many hours are on the heads? Do you know?

Go to JFR's website and compare your headwear to their drawings. Maybe you can narrow down what kind of wear you have and figure out what the problem is. Without having the machine in front of me, there is no real way to find your problem.
 
I appreciate your diagnosis, Quantagee.

I have had this machine since '95. I don't know how many hours were on it before I got it but I have only gone thru about ten reels of tape since I've had it. I don't know off the top of my head how many hours that is, but it can't be much in ten years. I probably recorded with it last about three or four years ago.

The reason I don't think it's the head is because I'm not even getting an input signal for 3 & 7 so it starts sooner in the chain. I just gotta get the manual 'cause I'm driving blind at this point.

Thanks for all the help!

scott
 
Sickstring said:
I have had this machine since '95. I don't know how many hours were on it before I got it but I have only gone thru about ten reels of tape since I've had it. I don't know off the top of my head how many hours that is, but it can't be much in ten years. I probably recorded with it last about three or four years ago.

The reason I don't think it's the head is because I'm not even getting an input signal for 3 & 7 so it starts sooner in the chain. I just gotta get the manual 'cause I'm driving blind at this point.

Thanks for all the help!

scott
Click to expand...

That is good news. Get out the Oscope and meter and have at it. It should not take any time at all to solve the problem.

Good Luck.
 
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