novation drumstation broken

[nochtanseenspecht]

just got one broken.. it is a v1.0
knobs don't work, previous owner said it had to do with with the power supply.
i have another powersupply wich is good.
on the regulators i messure 4,8V, so that should be fine. i allready changed the caps at the power inlet.
the midi to dinsync works, so thats nice, and also i can trigger the notes with my keyboard.
only cant edit them. could it be a software problem ? i noticed the little window on 1 of the eeproms wasn't
completely covered.. would that matter ? any help would be apreciated !! 

[Gordonjcp]

Are you sure that the power supply is correct?  It may need to be an *AC* supply for the internal power supply to work properly.  Get a pic of the board around the power socket and regulators, and I'll see if I can work out what's what.

Other than that, you'll probably find the knobs are selected by... a 4051 multiplexer.  Guess what?  It's probably dead.

[nochtanseenspecht]

thanks Gordon !
i will take a look at it + pics later on, i just closed it up again.it hangs between its new friends and does its job for now 
exept for the knobs, everything works fine, even the switches for conga, toms etc function..
i'm about to test how it respond to cc's.. if i can shape the sounds that way i can live with it i guess..
at least it's a very cheap midi-sync converter so far. and the 808/909 sounds are tasty..

but if i open her up again i will check for the 4051 multiplexer..  just hope it is not smd, like the rest 
could i just swap it for a new one you think ?i see it's a very cheap component 

anyway thanks a lot for your help ! i have now an idea where to search for the problem

[nochtanseenspecht]

well, all parameters respond to midi cc, so that's nice.. think i go play with it for a while before i open it up again

[natere2ster]

Did you get the unit working ok?

Just curious as I am having a problem with my power supply (different unit altogether) but am interested in voltage regulators and power rails (seems the first step to check in any unit!).



Cheers,

Nate

[nochtanseenspecht]

no, but for me it is ok.
i remember i checked for a 4051, wich wasn't there
their factory psu are known to be weak, first try another adapter with more mA
if that doesn't help, measure the regulator output
good luck !

[nochtanseenspecht]

ok she broke again
seems to be a faulty smd condensator or either one of the regulators.. but thats ok
anyway i checked what ICs are inside, and apart from the opamps and DA converters
i found :

HC138  (2x)
HC574  (5x)
ADSP2181  (1x big square IC)

i hope Gordon reads this ; could any of these ICs have something to do with the problem mentioned in the first post ?
Cheers David

[Gordonjcp]

Check the rails derived from the power supply, and see if the outputs from the pots seem sane.  Any chance of a couple of decently high-res pics of the board?

[nochtanseenspecht]

hey thanks Gordon, i fixed it some time ago, the non functioning knob problem still exist,
but all works fine over midi. i guess i just live with it, it is not my main drummachine anyway