Fader Trouble

[bigatrock]

I have 3 4800s. One is fully functional. The faders wont move on thier own on the other 2. When I put faders 1-8 from one the trouble units into the good unit they worked fine. Also on one of the trouble units you can actually hear a noise coming from the faders.

 

[skier]

What you report makes sense. It'd be difficult to believe that all the faders on both units had all failed, unless they were victims of a lightning strike or some such. One or several failed faders — possibly — all of them? Not likely. The far more likely cause is something like a failure of some common element of the fader driver circuitry. But, without a schematic or other info related to how the system is designed to operate, there's no way to know how Tascam implemented fader driver circuitry.

Similarly, the problem could also be related to some corrupted microcode that implements fader movement. But again, without the code to review (as with the schematic), we can only guess as to how the circuit or code is designed. This lack of information essentially makes our mixers a "black box" for which we can only speculate as to how it operates or as to the cause of such a problem.

HOWEVER, it may pay for you to contact Tascam to get some estimate as to what they might charge to repair one or both units. They can't know what's wrong for sure, but they likely have seen some similar problems over the years and should have more than an inkling as to what is likely to be the cause. They may even suggest some testing you can perform so as to give some insight as to cause of the problem. Then, you can make a decision as to whether or not the estimated price of repair and related shipping make sense to consider.

 

[Arjan P]

@bigatrock I would suggest you run a diagnostic test on the faders. Use the Diagnostic Test mode as illustrated below. To get into this mode (also factory reset here), power up the mixer while holding down SHIFT and OUTPUT ASSIGN 1 and 2 butons.

 

[skier]

Great suggestion! And I didn't know it.

Arjan, I can find nothing in the user manual about diagnostics. And I just looked at the Tascam site and found nothing like that there. Is there another manual or a service manual available somewhere? Or perhaps something someone has posted here regarding additional info for the DM mixers? TIA!

 

[bigatrock]

Thanks for the reply guys. I have run the diagnostics and reset both machines. No activity. Takes about 2 seconds and the test is done. Eventually I will contact Tascam after I'm tired of experimenting.

 

[cmaffia]

http://www.tascamforums.com/threads/service-manuals.55/

 

[cmaffia]

Also there is a fellow forum user who parted his DM3200 and is selling perfectly good parts for replacement. He has both sets of fader banks up for sale if it ends up you need to replace.

http://www.ebay.com/itm/Tascam-DM32...533061?hash=item2f008a6645:g:t6cAAOSwDKtY1fCC

 

[skier]

http://www.tascamforums.com/threads/service-manuals.55/

FANTASTIC! Thank you cmaffia! I've explored the diagnostics to which Arjan provided the Easter Egg code and they will be useful. But I also want the entire info cache of technical/service manuals to help resolve any future problems I may experience. I appreciate it!

 

[cmaffia]

I just reread the original post. If the fader bank works in your fully functional unit then it's not the fader bank. The problem would have to be somewhere before it and from what I see from the schematics, it looks like that would be the main PCB.

 

[cmaffia]

I'd also check the cable connecting the fader bank to the mainboard as well by swapping that from the bad unit to the good if possible but I'm putting my money on something is up with the fader controller portion of the mainboard. Other than not moving on their own, do the faders function? Can you see them move on the LCD display? Do they raise and lower input volumes?