Tascam 388 channel 1 not recording

lawsonfeltman said:
Head cleaning wouldn't effect this issue, but the heads are clean as a whistle.

Using Quantegy 457.

To reseat the amp cards I need to remove the bottom panel, yes?

Is that just as simple as unscrewing all of the screws on the bottom and removing the panel? Anything to be aware of before I remove those screws?

Thanks a lot
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:facepalm:

Sorry...I re-read your post...I read too quickly and missed the key issue.

Okay, just do this: connect a source to channel 1, set your trim as appropriate, raise the channel fader to the shaded section, raise the buss master 1-3-5-7 fader to the shaded area, route to group 1-2, pan hard L, now check if the signal is present at the buss 1 output jack. Report back.

Don't do anything else other than this test just yet.
 
Hi guys, after cleaning the heads we found only channel 6 and 7 to be able to record, the others recorded really really faintly. The other issue is that the tape is screeching as it plays, causing the recording to distort and screech too. Any ideas anyone??
 
sweetbeats said:
:facepalm:

Sorry...I re-read your post...I read too quickly and missed the key issue.

Okay, just do this: connect a source to channel 1, set your trim as appropriate, raise the channel fader to the shaded section, raise the buss master 1-3-5-7 fader to the shaded area, route to group 1-2, pan hard L, now check if the signal is present at the buss 1 output jack. Report back.

Don't do anything else other than this test just yet.
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Hey Sweetbeats,

Thanks for your response. I did the test you outlined, and sure enough, no signal is present in the buss 1 output jack... all the other busses are rockin. What's the next step? Should I pop off the top cover and have a look at the card and try a reseat?

Cheers
 
No. I suspect it has nothing to do with amp cards. It is in the mixing section. When I have time I need to look at the schematics to develop the next test to narrow where the problem may be.

And stop using sticky tape!!! :eek: :D
 
sweetbeats said:
No. I suspect it has nothing to do with amp cards. It is in the mixing section. When I have time I need to look at the schematics to develop the next test to narrow where the problem may be.

And stop using sticky tape!!! :eek: :D
Click to expand...

Thanks much. Looking forward to sorting this problem...
 
lawsonfeltman said:
Hey Sweetbeats,

Thanks for your response. I did the test you outlined, and sure enough, no signal is present in the buss 1 output jack... all the other busses are rockin. What's the next step?
Click to expand...

And if you do that test on any of the other mixer channels 2~7 you get signal out of all BUSS output jacks including #1, yes?
 
sweetbeats said:
And if you do that test on any of the other mixer channels 2~7 you get signal out of all BUSS output jacks including #1, yes?
Click to expand...

Yes, I just confirmed that signal is present at the BUSS OUTPUT #1 when shipping from any channel other than #1. For some reason, channel one just doesn't want to go to bus 1.

Any ideas for a remedy?
 
I suspect you have a corroded connection or bad solder joint or solder trace on the "M. BUSS PCB" or maybe on the input PCB. The M. BUSS PCB is a long PCB that runs across the bottom of all the channel cards and master section cards. You can't miss it when you take the bottom cover off the 388.

  1. Unplug the unit from the power source.
  2. Switch the power on and wait a few minutes minutes (yes I know its unplugged...we're just draining the power supply for safety).
  3. Tip the 388 on its side and make sure it is stable.
  4. Remove all the screws fastening the bottom panel to the chassis.
  5. Set the bottom panel aside.
  6. Locate the loooooooong PCB assembly. That's the M. BUSS PCB.
  7. Locate pin #1 of the connector P104 on the input PCB. That's where signal routed to PGM BUSS 1 goes out of the mixer strip to all its possible destinations. Its the connector closest to the channel fader and I *think* pin #1 is the pin also closest to the channel fader. P104 on the input PCB connects to P701 on the M. BUSS PCB.
  8. Gently exercise the connection between the input PCB and the M. BUSS PCB.
  9. Look for any obvious damage to the traces leading to and from this connection, and if you have a magnifying glass and can look in there, see if the solder joints for pin #1 on P104 and P701 look janky.
  10. If you can't see any obvious damage or jankiness, and you have exercised the connection, plug the unit in, turn it on and do the previous test again.
  11. If it still isn't working, exercise the connection while trying to pass audio and see if you get any signal to pass intermittently.
  12. Report back.

Do you have a multimeter? It doesn't need to be a fancy one...any basic multimeter will do. I'm asking because you may need it.
 
...

I've worked many small repair miracles just pulling & reseating cards & connectors over many years & various pieces of gear. Many times over. Countless times. It's always one of the first things to check when you go in deep. Contacts will often tend to open or go flakey with age, tarnish & just sitting around. Using a contact cleaner when you're in there can't hurt either, but most often a good reseating does the trick.
:spank::eek:;)
 
Hello all,
I have just bought the greatly coveted Tascam 388 off my friend. I am relatively new to tape machines but I am adamant to fix it up myself and any repair/service is likely to be more than the price I paid for it.
So far:
I have cleaned the heads with high-percentage alchohol and cotton buds.
I loaded brand new tape.
I have tested the transport.
I have checked all the inputs are working.

Firstly the transport has some problems including a screeching noise some of the time while it is playing. As well as this, to rewind or fast forward it requires some encouragement, that is, pulling slightly on the pinch roller.
All of these do not appear to be major problems.
When I have come to record through the mic and line inputs it sounds fine as I am monitoring it but when I listen back the sound is either very faint or very noisey, screechy, distorted and nasty. This issue makes the machine unusable so I must fix it!
Can someone please advise me on how I should start to look for the problem?

cheers
 
Is the tape making good contact with the head during playback? I've seen a lot of stuck or partially stuck tape lifters on Tascam machines.
Also, unfortunately there is no such thing as brand new Scotch recording tape (3M left the business sometime around 1995/1996). Can you let us know the tape model number? Depending on the type, it too might be sticky.
 
The scotch recording tape was sealed in a packet (That is what I meant by new). Since I have put the new tape, the sound recorded has got significantly clearer. It has also stopped making that screeching noise, which I think was coming through the heads and was being recorded. This has lead me to think that the problem was not in the heads! What is the best and most reliable tape to buy for this machine?

I am also unable to record on Channel 8, but I am unsure if this related to the issue.
 
So is this new (old stock sealed ) tape working? With the previous schreeching noise is it possible you had sticky tape?
 
Thanks J.harv is this the one RMG LPR 35 1/4" 549m Trident - Thomann UK ? That looks very good. Are there any major sonic differences between this and older brands of tape?

Yes, it appears the screeching has gone away with the new tape. It is still a significantly lower fidelity than I have heard form another 388 and I still have not got track 8 to record properly. Is it very common for one track to go bust?
 
izaakbinet said:
Thanks J.harv is this the one RMG LPR 35 1/4" 549m Trident - Thomann UK ? That looks very good. Are there any major sonic differences between this and older brands of tape?

Yes, it appears the screeching has gone away with the new tape. It is still a significantly lower fidelity than I have heard form another 388 and I still have not got track 8 to record properly. Is it very common for one track to go bust?
Click to expand...

Thats the stuff. I couldn't tell you about any sonic differences between this and older brands because the new stuff is all I have ever used.
Your track 8 problem could be because of the wear in the head. The tape cuts a path in the head over time and the edge tracks(1&8) can suffer from this. The new tape is probably cut a little wider than this wear pattern and tracks 1 and 8 won't make the best contact with the tape. My 388 did this for a while. But after using the new tape for a while, it actually made the wear pattern a bit wider and the tracks now play good.
 
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