Mackie SRS1500 - Woofer Blown, No Power

[audiohauz]

Hello,

I was at a gig and was pushing the subwoofer a little to hard. Consequently, the sub stopped and saw a bit of smoke and you could smell the burnt woofer.
This was last year and figure I would try and DIY the repair. The amp does not power up. I removed the back to reveal the amp/board. The fuse at the power (AC Input Board) was burnt. I inspected the rest of the components to the best of my ability and do not see anything unusual.

Could this repair be as simple as replacing the fuse? Did the speaker blow and as a result blew the fuse? I will have a fuse to replace by tomorrow. If it powers on, what should i check before hooking up a woofer to the terminals? I have a few smaller woofers laying around i can use before I purchase a replacement. I also picked up a multimeter to troubleshoot if needed. I have very basic knowledge of circuits and components, but im handy. Any info, guiding, etc would be greatly appreciated.

(ps - I have the srs1500 service manual with schematics, reference parts)

Hoping to get this brute working again!

Thank you in advance!

[Enzo]

If you see a burnt up part, it is bad. However most bad parts look no different.

System fails, burns up speaker. Or overdrive speaker until it melts and then shorts out system. Kinda doesn't matter - chicken and egg sort of thing. Your speaker is probably gone, and the amp is probably blown.

It is real likely the amp is shot and needs a rebuild. You would be the luckiest man in the world if the blown speaker and burnt smell was only a blown fuse.

First thing I do is run it up on a variac with a current meter. Failing that, make a "light bulb limiter" and use it.

Work with no speaker or load until we know the amp is stable. If it powers up, aside from my surprise, first thing is to see if there is DC voltage on the speaker wires.

CHances are good there are shorted output transistors at the very least.

[audiohauz]

Thank you for chiming in, Enzo!

First thing I do is run it up on a variac with a current meter. Failing that, make a "light bulb limiter" and use it.

I don't have a variac just a multimeter, but looking at videos I can put together a light bulb limiter (via Uncle Doug and other). I'm on my way to pick up extra fuses, once installed, Do i power it up (with nothing connected to speaker terminals) to see if the green led lights up or wait til I put together this limiter, etc..

[Enzo]

No, before anything you go through the large semiconductors looking for any that are shorted.

I was being unnecessarily flippant by saying first thing.

I use my ohm meter to look for things that would cause fuses to blow.