DINX4 MIDI when touching connectors

[normen]

Hi!

I am new to this forum and would like to ask a question.

I am building my second LC MidiBox and have some problems with my DINX4 (V2, from Mike).

I have connected 2 DINX4 modules and two LCD's to the core.

Now on both of the DINX the "upper row" (looking from the bottom of the board with the copyright note up right) of connectors does not work. So on both boards just four of the connectors of each chip seem to work properly.

The connectors on the upper side send their midi values randomly, especially when touching the connectors.

I checked all input resistors on both boards and could not find the problem.

Any help yould be greatly appreciated

Regards,

Normen Hansen

[normen]

UPDATE:

I installed the I/O test from http://ucapps.de/mios/srio_interconnection_test_v1a.zip and I cannot measure the +5V on the upper row as well. So it seems there is some connection problem.

Giving the unusual error pattern (the shift registers work, just not the connectors on one side) I still hope there is somebody who can point me to a solution.

Thanks,

Normen

[cimo]

the only solution i can see is you checking your hardware, shortcuts, missing contacts bad soldering, if you feel like upload an high res image of the traces

Simone

[stryd_one]

Welcome aboard man. It sounds like you've left the top row floating (unconnected), I think you've missed out one of the jumper wires to the power buss there.

Cimo's on the money as usual - a pic would be great.

[normen]

I will check everything again but could this explain that both are not working? Maybe I forgot to install one bridge in general? Is there a "suspiciuos bridge" that I could have forgotten? On top? Those on the lower side seem to be ok.

[stryd_one]

There is a specific one, but explaining it will take me longer than it will take you to check all of them :)

[normen]

Hi again. I seem to have all 10 bridges in place and they all look good. I will measure all to see if there are any cold soldering spots. Meanwhile I took some photos of the boards.

Of course checked all the spots that soldering-wise look a little "wild" more than 10 times :)

Regards,

Normen

Edit:

The cables soldered directly to the bottom of the board are there because there was no hole in the board so I could not use the pin-row. (Photos are DINX#1 bottom and DINX#2 top)

[cimo]

[normen]

People, thank you very much. I found the problem.

It was in fact a bridge on the top (thank you for saving me a lot of time). The long bridge connecting to the resistor ends was faulty.

The funny thing is.. I had 3 DINX modules which I all exchanged with each other to find the faulty one. I made the same mistake twice! One end of the bridge was not going far enough through the hole and thus did not get any tin on it. On two boards! the exact same thing :D

Regards,

Normen