Problem with my AIN 8 Pots Fault

[potain]

hi Midibox Mans. Ilove this project, is its really my first box its runs. my project have a pic18f452 with mios e 128in128out64pots aplication. now i only have one expansion AIN and DIN. but more later my midibox have 2 ain and 2 din. now i connected 36 pots. 32 mued and 4 not multipxeder.

my project runs with cubase 3sx. its fine. relly fine, but have one problem. 8 potentiometers dont work. this potenciometers are connected in the first mul. Today i replace all multiplexers, and test all connections, but this problem persists. have explication?

maybe i'm a noob, but i search in the forum board and dont catch this problem.

Very Very sorry for my english is really bad.

thank you to all

EDIT for add pictures about this project.

Edited December 9, 2009 by potain

[J Martins]

Well my friend potain, just a reply to put a flag for other dudes help you.

I'm sure you doublecheked all the whole project, and with my low skills on this project my only thoughts are focused on the PIC or again in the multiplexers or maybe in your wiring method.

Can someone suggest something to help my friend potain?

[stuartm]

Check the voltages on the potentiometers (on the Vd input against ground, not the sliding contact).

Should be 5V.

If not, check the Vd pin of J7 on AIN against ground, should be 5V.

Try to exchange the multiplexer lines that go to the Core J5 (A0 to A7), put the cable of the non-working potentiometers multiplexer to another input, i.e. put the cable that goes to A4 to A5 and the cable that goes to A5 to A4 (if the potentionmeters on the A4 or A5 line do not work).

/edit: If I understand your posting correctly, the potentiometers not working are connected to the IC1 multiplexer of the AIN, so try to exchange the A0 line to another core input as described above.

Just try to systematically remove or exchange things until you get it working. That way you might find our if the fault is in the pots, their power supply, the AIN, the cable to the core or the core itself (I hope not!)

Edited December 15, 2009 by stuartm

[potain]

Check the voltages on the potentiometers (on the Vd input against ground, not the sliding contact).

Should be 5V.

If not, check the Vd pin of J7 on AIN against ground, should be 5V.

Try to exchange the multiplexer lines that go to the Core J5 (A0 to A7), put the cable of the non-working potentiometers multiplexer to another input, i.e. put the cable that goes to A4 to A5 and the cable that goes to A5 to A4 (if the potentionmeters on the A4 or A5 line do not work).

/edit: If I understand your posting correctly, the potentiometers not working are connected to the IC1 multiplexer of the AIN, so try to exchange the A0 line to another core input as described above.

Just try to systematically remove or exchange things until you get it working. That way you might find our if the fault is in the pots, their power supply, the AIN, the cable to the core or the core itself (I hope not!)

thanks for all reply's

I Catch the problem... so, its really stupid! very stupid

the problem is the first wire, this wire as been connected in the core, and the first MUx, but have one union in the mid, and this union has been connected to the Ground! :( is this the problem, if signal is ground, the value is 0.

thanks for your help.

iam a really noob, in this projects.

now I made the second AIN, in Dot board, and have 64 pots connects,

the next step is made onde more dinX4 for have 64 pots and more later i post the finnaly pictures.

thanks a lot!

[stuartm]

Great news!

Glad we could help, and don't worry, everybody starts as a noob ;)