I have an original iPhone i bought used from a friend. it's in good physical condition, and works perfectly, but I am having one problem: the speaker will stop working occasionally never in a call, but when it's supposed to ring or make a sound, sometimes, it just vibrates. this wouldn't be any more than an annoyance, except that it's also my alarm clock. I've been late to work 3 times in the last week. I noticed this problem about 3 weeks ago, but it is becoming a lot more frequent, and seems to favor doing it when the alarms on. it started doing it maybe 3% of the time, but now does it maybe 45% of the time. any hints or fixes? i've tried restarting it when i have the issue, but that doesn't really do anything.