Hello everybody,
I repair a lot of old Alesis MIDI sequencers. They are pretty simple, so failures aren't too common besides a few causes, however this one i am a little confused by
It has a speaker that is not much different from a PC "beep" speaker. You can tell it to turn the click track on or off, and it'll output a "tock" sound over the speaker. It also is supposed to make a "tock" on power on and power off.
This is the first one i've come across though where the speaker does absolutely nothing. I opened it and checked the wiring, no problems there. I then removed the wires from the speaker to test the impedance, and it varied between 8 and 15. It is an 8 ohm, 0.5w speaker so i assume that is fine.
I then tried connecting a known good 9V battery to the two speaker terminals but still nothing. I then set my multimeter to AC voltage and put it on both leads going to the speaker. When the click track was supposed to be going, it went back and forth between 0.002v and 0.750v so i assume the click track output is working.
edit: I checked the service manual and it makes no mention of the speaker or how to test it if not working.