mbseq v2 unstable / periodically insane behaviour

Testing/Troubleshooting
1

Hi

After 4-10 minutes my seq start acting weird, it is not the wires or something like that, cause it all start well…

When powering on the unit, the vesion and all shows in the display, and all funtions/leds/lcd’s behaves normally.

however after some minutes of use(can be up to 20 minutes, it suddenly goes loco on me…

.buttons is no longer mapped to the normal function, and lcd & leds blinks and shows nonsense values.

It transmits weird stuff on the midi out too (in some occations wonderful weird stuff… but is rather annoying in a live situation)

The only sollution to this, is to reboot the mbseq.

To me it seems likely that this is related to the core/pic, as I said, after a reboot, all works well again…

Someone here experienced this before?  What was the sollution?

Can I have a bad pic?

Best regards.

Ole Peder, Norway

2

Does the 7805 get very hot? What is the main voltage when it get’s weird? Still 5 volts?

3

hi

  The 7805 does not get very hot at all, I have good cooling (guess it’s about 40 degrees celcius)

5 volt is stable even when mbseq goes loco…

(Power input is 10v 1000mA DC)

Ole P

4

Could be a bad PIC… Dud crystal maybe? Have you tried running a different app on the core?

5

Hi Ole,

does it also happen when the LCD backlights are not connected? Then it’s definitely a thermal issue, caused by the too high voltage before the 7805 (7..8V would be better)

Note: a core module can be supplied even with 12 or 15V at J1, but only if the power consumption is low enough, so that the 7805 doesn’t get too hot. The two BLs, and also the LEDs, consume so much power, that a better fitting PSU is required.

Best Regards, Thorsten.

P.S.: before you buy a new PIC (I don’t think that this is a problem!), consider to buy a PIC18F4620 and PIC16F88 (for MIDI out), so that you can use the new MBSEQ V3 firmware :slight_smile:

6

Tried a 7VDC 1200mA adapter today, but same darn thing again… I guess it’s not my year…

I simply love the mbseq the time it’s stable, so I will continue the quest

I’ll try to reset the pic, and reupload the firmware again…

If this fails, I’ll order the PIC18F4620.  As I have the LTC module, do I need the PIC16F88 to get midi with the new pic?

Kind regards

Ole Peder

7

Hi Ole,

If this fails, I’ll order the PIC18F4620.  As I have the LTC module, do I need the PIC16F88 to get midi with the new pic?

yes, it’s unfortunately required (see also the FAQ: http://www.midibox.org/dokuwiki/doku.php?id=mios_pic18f4620)

Is the 5V voltage stable over the whole time, or does is sink slowly? The PIC will reset automatically, once it is sunk below 4.6V (so far I remember)

Best Regards, Thorsten.

8

I just wanted to update my own old thread in case anyone else experience this in the future… 

I have during the last week removed all the connections to/from the front panel, rebuilded the front panel internals on a new veroboard and rewired to the core / din / dout.

Woilaa!!! “bug” magically vanished… I guess my previous “spaghetti” wires was the cause of error in this case… Doh!!!

The unic can play 4ever…  I can even adjust the brighness to the full on the lcd’s too :wink:

As all is working finally… it’s time to move on… V3 parts ordered…