Mask Alert Not Working HELP!

Hi all. I have a Respironics Remstar System One with Humidifier. The machine is apprx. 7 years old. The mask alert recently has been working sporadically/intermittently. And, I need it to work because I rip my Circandience Sleepweaver Elan mask off at least once per night. Is it just old and finally not working? I can't afford a new machine right now and haven't even come close to meeting my annual deductible for health insurance.

Thanks all in advance for any suggestions!!!!