Have a mpa-101, has power but no output. I've heard this is a common problem, and that I need to check the electrolitics, but which ones?

You cannot check the diodes problem while they are in circuit. It could be several factors, but if you have gone that far, remove diodes and check orientation before removal, test one at a time.

Water ingress is common. You can sometimes get away with a squirt of WD40 or similar which can loosen any corrosion and get the switch working again. If you have the confidence to then strip the switch gear down and clean the contacts with a bit of wet & dry paper.

Hi there. I noticed that sometimes Android devices seem to have trouble connecting to certain access points or.they seem to stop connecting alltoghether to certain routers. Sometimes this method can help: Select the network you are trying to connect to and select "forget this network". Reboot the tablet and try to reconnect again. Sometimes this doesn't work on the first try. If that doesn't work I have heard of other fixes but they require "rooting" the tablet which could be potentiall dangerous. Another thing you can try if that doesn't work is change the security to a different encryption type. Your password will either be WEP or WPA. Whatever it is try to change it to the other. I cannot give you detailed instructions on this because I don't know your router model or its current settings. Hopefully this helps and leave a comment if you have further questions. Good luck!

This will depend on whether your sub-woofer is powered (has it's own built in amplifier) or not. If it is not powered it will need connecting to an amplifier. If it is powered you will need a line level output either on the amp or the mixer.
Many modern amplifiers (and some mixers) have a dedicated output for sub-woofers in which case this is the best place for it because the higher frequencies will have been filtered out.
Some high quality amplifiers like the JAMO MPA 101 have a filter switch and adjustable filter level for powering sub-woofers. You then just connect the speaker to the speaker terminals in the normal way.

Otherwise on a p.a. mixer you could use the main output, one of the auxiliary, monitor or sub-mix outputs. If you are not using the main output you will need to route signal to the appropriate output accordingly. Either way your output signal will cover the full frequency range - your subwoofer may have built in filtering or you may need to use some sort of crossover to split the signal between the sub-woofer and the rest of your speaker system.

The 201 is 100w in to 4ohms and the 101 is 50w into 4 ohms other then that there the same

Check the small electrolytics on the power supply board for high ESR, Very common problem on these amps. Protect circuit stays latched due to high ripple from PS.

short answer yes... Long answer... Amp Failure: There are many different ways that an amp can fail but the two most common failures are shorted output transistors and blown power supply transistors (< those are not blown). There are several types of protection circuits in amplifiers. The most common are over-current and thermal. The over-current protection is supposed to protect the output transistors. Sometimes it doesn't work well enough to prevent the failure of the output transistors but it will work well enough to shut the supply down before the power supply FETs are destroyed. If the amp remains in protect mode, goes into protect mode or blows the fuse as soon as the remote voltage is applied, shorted output transistors are almost certainly the cause. If the fuse protecting the amp is too large, if the protection circuit doesn't respond quickly enough or if the power supply is poorly designed, the power supply transistors may fail. If you see a lot of black soot on the power supply transistors (near the power transformer), the power supply transistors have failed. Soot on the board doesn't necessarily mean the transistors have failed. Sometimes, technicians don't clean up the mess from a previous failure. Transistor Failure/Checking Transistors: In general, when a transistor fails, it will either short (common for output AND power supply transistors) or open (common for power supply transistors). Transistors act like valves. They control the current flowing through a circuit. A shorted transistor acts like a valve that's stuck open (passing too much current). In the case of an output transistor, the shorted transistors tries to deliver the full rail voltage to the speaker output terminal. If you've ever seen a damaged amp that pushed or pulled the speaker cone to its limits when the amp powered up (common on some Rockford amplifiers), that was almost certainly due to a shorted output transistor. When checking transistors, you most commonly look for shorted connections inside the transistor. You do this by using a multimeter to look for low resistance connections between the transistor's terminals. Note: I used the terms short and open on the previous paragraph. A short (short circuit) is a path through which current flows that should not be there. An open (open circuit) is a break in the circuit. It is most likely the power supply that has taken a ****.

I can almost guarantee that you'll find bad electrolytic caps on the power supply board to be the cause of the problem. I've seen several of these with the same problem. The protect circuit stays latched due to excessive ripple.

Hello, is this a Radio Shack PA amp or Jamo amp? The unit is probably in "Protect" mode. Is this a PA system or a receiver...receivers have a protection circuit that will not let the speaker relay activate if the amplifier output section is shorted and sending voltage towards the speakers...so they won't fry!!The speaker relay should activate within 3 to 5 seconds if your output section is ok.

barneyluc