dominik Posted February 8, 2004 Report Share Posted February 8, 2004 Hello!Since a few days my MF module does not work any more. I tested the module a week ago with the mf_example and the midibox_mf application and it worked fine.Now I disconnected all other modules and still nothing is moving.Current situation:- one motorfader connected to first port.- mf_example application successfully installed- when moving the fader by hand the display shows the right value, so the connection to the PIC seems to be ok.- when sending MIDI volume change messages the displayed value changes but there is no reaction on the physical position of the fader.- correct voltage for motorfader- motorfader working (if you e.g. give Vm to OUTA)- correct voltage for TC4427 and 75HC595Has anyone encountered a similar problem or knows where I could look for the reason for the problem, what I could check?Thanks for any help,Dominik Quote Link to comment Share on other sites More sharing options...
pay_c Posted February 9, 2004 Report Share Posted February 9, 2004 Perhaps try replacing the TC4427. Could be broken. Is it getting hot when it's connected? Is there a voltage coming out of the IC (the pin going to the MF)?Also when its working always check if it's getting to hot. You should use IC-heatsinks if it's to hot...Greets! Quote Link to comment Share on other sites More sharing options...
dominik Posted February 9, 2004 Author Report Share Posted February 9, 2004 Thanks for the quick answer.I replaced the TC4427 and the 75HC595, without success.The temperature of all ICs is ok even after long running times although I remember that some ICs got quite hot when I first misplaced the diodes. What could have been damaged by this?What exactly do you mean by "voltage coming out of the IC"?I measured a 5V voltage between Vs and Vd on J7 of the PIC. Furthermore the connections of the other J7 pins to the PIC are ok. Should I be able to see any voltage using a standard multimeter on these pins during volume change?Is it possible that these outputs of the PIC aren't working whereas the MIDI communication and LCD controlling works fine?Thanks again for any help that prevents me from redoing everything...Best regards,Dominik Quote Link to comment Share on other sites More sharing options...
Steven_C Posted February 9, 2004 Report Share Posted February 9, 2004 Once, all the LED's stopped working on my LC. Nothing was wrong with any of the circuitry for the LED's! So I tried re-installing the MIOS, and the LC app, still everything works except for the LED's!So I try another PIC18F452. Then it works fine! I still don't know what caused this, I'll try re-burning the bootstrap loader at some stage.I hope you sort it out soon!good luck dominik, from Steve Quote Link to comment Share on other sites More sharing options...
dominik Posted February 9, 2004 Author Report Share Posted February 9, 2004 Thanks for your help!You were right. I replaced the PIC and now everything works fine. It seems a bit strange that an IC can be damaged only partially, but this was definitely the reason.I first reprogrammed the (old) PIC. No problems but again no movement of my motor faders.But with the new PIC everything worked fine immediately.Best regards,Dominik Quote Link to comment Share on other sites More sharing options...
TK. Posted February 10, 2004 Report Share Posted February 10, 2004 Hi Dominik,your PIC has been damaged? Strange! Check the direction of the Schottky diodes (MF Module), they protect the digital circuit against negative transients from the motors.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
dominik Posted February 10, 2004 Author Report Share Posted February 10, 2004 Hello Thorsten!Yes, strange, that's what I thought as well.The diodes have the right direction. I misplaced one before and - unfortunately - the corresponding TC4427 got hot (probably too hot). So I could understand that this IC got damaged. But why did this affect the PIC, and - even more suprising - why did this affect only one part of the PIC.God knows why. Anyway, after replacing my PIC everything works fine. I hope this situation will last for a longer time...Many thanks to all of you who helped me,best regards,Dominik Quote Link to comment Share on other sites More sharing options...
Steven_C Posted February 10, 2004 Report Share Posted February 10, 2004 so your MF was working since you corrected the misplaced diode, but stopped working a short time later? Quote Link to comment Share on other sites More sharing options...
dominik Posted February 11, 2004 Author Report Share Posted February 11, 2004 Hello Thorsten.To summarize:1. I built Core module and tested several DIN/DOUT-modules => worked perfectly immediately.2. I connected a MF module with 1 fader (first port), so I did not realise that the diode for fader 15 was misplaced. Worked as well, no problems.3. I mounted additional 3 faders.4. MF module was connected to power a longer time => TC4427 for port 15 got hot (and probably damaged)5. not sure whether MF worked after recognizing overheating of TC4427.6. Unmounted the 3 faders, went back to step 2. PIC-MIDI-communication works fine, LCD display works fine, output of motorfaders works fine => no reaction of motorfaders on volume change messages7. Reprogrammed PIC with primary bootstrap loader, reloaded current MIOS version and motorfader-example application, no movement.8. Replaced PIC => everything works fine.So, I think we can stop the thread here. Nevertheless it remains strange to me, that it seems to be possible that one the PICS connections to the MF module are damaged.Anyway, now it works ;D Quote Link to comment Share on other sites More sharing options...
smashtv Posted February 12, 2004 Report Share Posted February 12, 2004 Just a quick note that the last few PIC failures that have been talked about here only had one pin, one set of I/O lines, or one function that failed, not the whole chip. So it's looking like the average failure mode of the PIC is just a few functions, not total failure......In other words any future troubleshooting of certain symptoms should involve swapping the chip with a known good one. ;)Have fun!SmashTV Quote Link to comment Share on other sites More sharing options...
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