Mackie hr624 fuse keeps blowing

Be sure the capacitor was replaced with the correct polarity?
in the beginning of my tech career I have replaced caps back words on accident. ..

i) I assume the fuse you mentioned was in the mains plug - did you also check the fuse in the TH15A mains input socket? This is accessed by pulling out the tab in the bottom section of the socket (below the centre pin). This is a 3.15Amp antisurge fuse, 20mm type.

ii) If this fuse has blown, then replace it & all may be well ...... but if it blows again, then move to step iii).

iii) With mains disconnected, remove rear panel (outer screws) & check the power supply PCB for damaged components, especially R111 & R112 (100ohms). If the latter are burnt or open circuited, then the amplifier module may have blown.

regards, Dave

This sounds like yet another case of bad connections or soldering in the amp. If it's not too old take it back to your dealer, they should fix it. These are designed (allegedly) to be used and should not fail in this way. If it is too old then open it up and with care - and with yourself isolated from earth and wearing insulating gloves wobble connections and components until you find the cause. We have had a couple of this sort of fault with newer mackie stuff and it's not been too hard to track down and fix if you're handy with a soldering iron.

If you have any doubts about being competent to do this sort of thing take it to someone who knows what they are doing, it should be a fairly quick fix.

This speaker at full power draws average 1.3A at 230V and 2.5A at 120V. Mackie's recommended fuses are in line with this so your fuse is actually too high a rating. It is possible you are using cheap fast blow fuses or are over-driving the speaker (which should cause the fuse to blow) These speakers are only capable of 118db sustained (@1M) so cannot be expected to cope with anything but small venues or gentle music.

It is likely that the O/P transistors have blown, especially if the fuse keeps blowing and the O/L led comes on. It's a repair shop jobbie

Mackie say this is not a user service part. If the fuse has blown there is probably a fault in the unit being their reasoning. I know for certain they tend to blow for no apparent reason so it is worth giving it a go. They are 5 x 20 Slow or time fuses. 7A for 120V and 4A for 230V

Essentially if the fuse goes, the unit is rendered useless until it is repaired. Replacing the fuse without repairing would likely cause further damage in the unit. Fuses blow for a reason that is usually a failure in the unit. Failures don't fix themselves. The ability to replace the fuse is therefore a moot point. To keep your unit safe ALWAYS power all interconnected equipment from the SAME power receptacle or conditioning module. This means running extension cords to powered speakers if that is what you have to get power the mixer. Powering mixers at one end of a room from a receptacle and the amps or speakers from a recpetacle on a stage at the other end will likely damage you equipment when a ground fault occurs or ground bounce in the building wiring ruptures the sensitive input/output circuits of your equipment.

This is a rare occurrance for these units. It means that either one or more of the rectifier diodes has shorted or that one of the voltage regulators is bad. In any case, this is not a unit I would suggest a novice attempt to repair. Can you update this with your location so I can suggest a repair center? The actual repair should be straightforward and not too expensive. Thanks, Dan

check ur power supply unit inside...there maybe component already shorted or short circuit...whether a transistor...