Faders 1-16 stuck in the infi position

[Casey_Pittman]

Peter,

Yeah same exact problem in all 3. I know it's not the slot because I can move a working one to that position and it works fine.

I talked with Steve Edgar with S&X Pro Audio in Wa. and he says this is a problem he is used to dealing with and said more than likely it is this chip. Apparently this chip is very prone to static electricity and is a common problem.

Do your faders randomly stick or are the motors constantly on driving them down?

-Casey

[Petersueco]

Different faders shows different symptoms.

I do have 2 fader that the motor is keeping them at the top. Some other faders just get stuck wherever they are but you just have to touch them slightly and they react and slide over to the right position.

Thanks for the info.

Peter Holmquist.

[macleod]

Well after talking to some techs about the problem We have narrowed it down to a chip located under a couple of the faders that send the motor information. This would explain why they are only effected when changing banks not in regular use. I'll be sending the boards to this guy and when it is all said and done I will have 2 working spares, Yay!!

-Casey

All my faders are stuck/being pulled down and this sounds like the solution to my problem.
Can anyone confirm what chip(s) you are talking about???
I am suspecting it is U908 (AD8803 motor drive) and or U903 (74HC595 on-off motors) HELP !
(I have already changed the majority of the .1uF caps (2 were fried) as well as chips U3, U8 and
U11 on my brain board (and it still works ))

I got this d8b for a "song" because it would not boot up (error 43 etc..) so I am not afraid
to mess with it. These chips are really inexpensive and not that difficult to replace.

Yes, I have changesd the Mobo battery, corrected the BIOS, formatted and installed a new(er)
hard drive, upgraded the memory, removed, tested, cleaned and reseated all ribbon cables
and reinstalled the OS (3.0) and service packs. and only 2 screws leftover
If I can fix this fader problem I will consider upgrading to OS 5.1.

[macleod]

Woo Hoo.......Found and ordered the AD8803 chips (66 cents each. $8 shipping)
Sharpen up the soldering iron nurse, we're going back in.

[Casey_Pittman]

Where did you find it for .88 cents? Digi-key charges 7.00 bucks for this thing!

-Casey

[macleod]

My appologies Casey, you are correct they are $7.70. I'm confusing them with the CD4051 chips I also ordered. I tend
to throw extra stuff in my cart until my purchases amount to the shippoing costs (at least) Makes me feel better. I also have extra stock of useless parts just in case I want to build a complete new unit.....
The AD8803's were the problem BTW. Changed them in the first two fader banks and voila, no more stuck faders.
The 9 way fader bank uses the AD8804 (which I did not throw in my cart) There's foresight for ya.

Gordon

[Casey_Pittman]

No problem Gordon, I have 3 bad fader boards and if this is all it takes then I'll dish out cash and do it myself! How difficult was it to replace?

-Casey

[sverred]

well, I'm glad I finally found this thread...

I now have two consoles with these exact symphtoms, where the motors in the first 16 faders only keep them in OFF-position.

I think I might have found a reason for it as well, as it became like this when I switched CPU/PSU from the one console that was allready like this. That cpu might send some "bad power" or something, 'cause when I changed back to the original CPU, it didn't work on that anymore either... My guess is that it lies in the powering. (BTW: They did not become like this at the same place, so it is not in my house power, if so.)

Chip's ordered - will post how it works out!

Edit: Casey, did you get your d8b working after changing these chips?

[Casey_Pittman]

Casey, did you get your d8b working after changing these chips?

Funny story, I bought the chip, de-soldered the faders that were in the way, cut away the leads from the old chip and cleaned the pads. But when it came time to remove the chip from the board, it was glued down.
And upon trying to remove the chip I pulled up the trace on the PCB that was sooooo conveniently run through the footprint So at this point I'm still running without the first 8 channels. Ahh well live and learn, patching is my friend

-Casey

[sverred]

Shit, I was waiting for a "It was easy, everything worked out well" reply... Did you talk to mr. macleod about this?