SammichSID went insane.

MIDIbox SID
1

I was at the end of the assembly manual, the part when you install the microprocessor + additionals ICs. I quadruple checked all the voltages, as stated in the manual and they were correct.

Uploader worked, and it stated that the MIOS was uploaded successfully.

But when I turn on the sammichSID, it goes completely insane. It looks like MIOS is working properly, the screen shows coherent messages - but it jumps from screen to screen, tries dumping patches, LEDs blink, all values change etc.

Seems like it gets false control messages. 

Anyone a suggestion how to solve this issue? Also, I noticed it gets worse if I touch the controls  - maybe it just doesn’t like me? 

2

I think I figured out what I did wrong. It probably has something to do with grounding unused analog inputs of the core.

3

The sammichSID doesn’t scan analog inputs, therefore this is very likely not the reason for this issue.

It seems to be related to the connections around the 74HC165 ICs, which scan the buttons and encoders.

Best Regards, Thorsten.

4

Check the resistor networks are soldered correctly and well on the control surface.  Post some high res photos of your boards front and back and we can see if any of the solderwork looks suspect.  If you take a look through the forum for people with Sammich issues - they are usually caused by poor solderwork or PSU spec.

5

The sammichSID doesn’t scan analog inputs, therefore this is very likely not the reason for this issue.

It seems to be related to the connections around the 74HC165 ICs, which scan the buttons and encoders.

Best Regards, Thorsten.

I must be retarted. I forgot the resistor networks and now I can’t find them in my stash. I thought these holes were for testing 

Well, off to a local electronics shop I go.

6

I installed the missing networks and remaining components, and everything seems to function as it should now! I’m glad I finally finished it.

Thank you for your input.

7

Fine! :slight_smile:

Best Regards, Thorsten.