Beeping Insanity - Rep1 non-piezo beeping

[AdanA]

Hi all,

I've got a Rep1 that, since getting a new Mightyboard, has insisted on making random loud beeps any time a heater is on (HBP preheat, extruder). (Come to think of it, I haven't tested extruder alone. Hmm.)

Today I got very annoyed with it and took a drill to the plastic piezo buzzer enclosure. I was intending to just open the hole and reduce the efficiency of the resonator, thus quieting it a little. The bit grabbed, though, and I ended up denting the brass bender disk. 

Upon restarting I was pleased to hear that the song could still play, just very quietly. Success, I thought! 

Yet upon beginning the HBP preheat I was disappointed to hear the same old beeping, just as loud as before. Pretty sure it's not coming from the damaged piezo now. 

Joseph mentioned once that beeping can happen as a result of the PWM of the heating power impulses. I've heard that on the bot that has the Mbot clone board. That's much quieter, and varies a bit in frequency. This one is very loud and always the same (as far as I can tell) frequency.

Thanks in advance for help - it's driving me up the beeping wall!

Adan