








Would appreciate any help with a Mirage OM-5 (2000/2001) Tower Speaker set - Subwoofers shut off after about 30 minutes of use (both units).
Found a pair of Mirage OM-5s in the dumpster with the boards also removed but nearby. Basically, everything is there with the exception of one of the subwoofer mesh covers.
Initial testing:
I hooked both of them up, sent some sound through them via a good AVR. They sounded great... until the light on the front of each went red after about 30 minutes. Once this happens, perhaps it's in standby mode, but I cannot get the subwoofers to work again like this.
I do a total power off on the tower, wait a few seconds, and even then, I usually have to close whatever tab was playing music, power off the AVR, then start turning stuff on from the tower to the AV, it's kind of picky. The mids/tweeters still go, but the subs (2 on each tower) are totally dead with a red light. It will green light every time at the start but then shut off. This happens on both towers.
Fixing Attempts:
My first instinct was to recap the entire amp board and even the tweeter board for good measure; these are 25-year-old caps, so maybe they were dying. No dice, still fails after 30 minutes. I triple-checked all the positive/negative directions. They are the correct cap types as well. Cap job was fine, even on the tweeter board (brown board in the pictures).
I thought it was overheating after this. I tried blowing a ton of air directly on the board with a fan (had the board partially out with the screws loosened so air could flow across the board and the caps). That did not work; same problem. I also tried crimping new wire and attaching it to the speaker drivers themselves with a more secure connection, thinking maybe heat was causing some kind of problem with the fit. Still has that 30-minute timeout period, no matter what I do.
I did some measuring with a multimeter, but I can't make heads or tails of much. If anyone can tell me the continuity checks I need. I can provide more pics of the chips if need be.
I checked on the 4 MOSFETs, and apparently they come out with a good reading.
I also replaced the IR2111, which are chips that are not soldered in. Still no changes.
Where I am now:
Really like the speakers when they work, but god damn, buying new amp boards, if that is even possible since these have 3 wires, some kind of extra connector (2-pin top right) is going to cost a ton with money I do not have right now. I blew close to 100 bucks on parts (some I didn't even need) trying to fix this thing. Still has the same problem. Works for 30 minutes, green light turns red, subwoofers stop moving.
AVR is a Denon x4700h. Powers my Klipsch passive speakers just fine.