Mackie Music - Page 5 - Recent Questions, Troubleshooting & Support

The resistor is 4.7ohms +/-5%

Yes, send this to a Makie repair facility. Chaances are there is a chip going bad... most likely the A-D or D-a convertor.

Try putting this is your freezer and then immediately test it. This MIGHT indicate if problem is easily found with circuit cooler spray.

Jose Miguel Carcamo Cruces do you have pictures of these j112 fet ? Thank you!

First, check the speaker itself to make sure it isn't blown. If so, replace it. If not, take the unit in for repair.

These subs are renowned for problems. The PSU and the output stages as well as the main driver are all weak and there are a number of companies that will upgrade them and sort out other issues such as vibrations. Assuming it is out of warranty and you really want to use this you would be best going to a specialist repairer to get it sorted not Mackie.

Bad FET circuit or leaky cap.

replace diodes D106 and D107

The internal amp is in need of repair. Are there any other symptoms or signs?

It sounds like a part is burning out. If you can look inside , look for a part turning brown or getting really hot in that area. That would be the easiest thing to do if you can get in there.

If there was no signal going through them, they shoulldn't overheat. However, if while they were on the AC line had a power surge, it's possible it took them out. It's time for the repair shop to see what's up.

Yes, you can use the A output, as long as you're OK with it being a mono system. It may be helpful to read the manual which has a lot of info including possible setup configurations. Here's a link- http://www.mackie.com/products/srm1801/pdf/SRM1801_OM.pdf

This will likely be a component level issue. I suggest taking it to the shop. Call and ask them, but some repair guys prefer you pull the amp out to save space in their shop.

I believe there is an internal fuse in these which, according to a friend who has these, seems to blow occasionally for no apparent reason. He has also had to send two back for replacement and would not buy again, they seem to be inherently unreliable although they sound great.

Either a short in the power supply such as diode(s), capacitor, or transistor(s) or in the power amp. It will require service. Replacing the fuse before repair will likely damage more components... don't do it!

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. ..

More in likely a voltage drop in the club, and the mixers power transformer was fighting for power, so it's brunt or burning up, also there are capacitors that filter the AC transformer hum, they Probably need to be replaced, this can be fixed tho, parts and labor might not be cheap...