Hi i have the Marshall MG15FXMSDM Dave Mustaine Megastack and i also have the programmable footswitch. the other day, i was plugged into a big surge protector and the footswitch was working fine. i unplugged it and moved it to the other room and not the footswitch will not turn on. it still works with other MG series amps, but it just will not turn on plugged into my amp. help?

That footswitch is the right one for the HAZ40 but, it is programmable. I recommend downloading the manual and follow the instructions for programming and make sure you are using it properly.

Sounds like either your "front-panel" switches are not set for channel switching or the footswitch's mechanical "Channel" switch is defective. According to the OM the "Channel Select Switch" on the front becomes inactive with the footswitch plugged in.

If disconnecting the footswitch causes this front-panel switch to operate properly then it has to be your mechanical switch in the footswitch. Repair of these footswitches are pretty simple provided you find a replacement and have soldering abilities.

Does your M foot switch work on the Fender? If you know how to use a multimeter you could check continuity by putting meter leads on plug of M foot switch(1 on tip, 1 on sleeve ) You should see a change in the multi meter when you depress switch. If so switch is good. Another easy test is with cap off a spare 1/4 plug -plug it in to foot switch jack.put a alligator or some such metal clip or wire and join(called short or shorting) the two inputs . If connecting and unconnecting results in switching then the foot switch is suspect. One fairly common thing is that foot switch and input jack are often sautered straight to a circuit board to save $ on production cost. Used to be all point to point where a wire was attached to 1/4" input and then wire went to circuit board or tubes. The wire has give, but not so with direct wiring to board. So the nut holding the 1/4" amp input gets loose(doesn't have to be loose for the following to happen) and a pull on the chord causes a break in the soldier and thus a break in the sound chain. Sometimes it will work intermittingly by putting a little pressure left, right, up or down on the plugged in plug. If so, it's the input jacks connection to the amp. If not it still could be that because putting pressure on plug may not be sufficient to affect a temporary reconnection. Since switch(the new one you made)works on Fender, but not Marshall I suspect the jack or foot switch circuitry past the input jack. If using some of the above the above tests leads you that direction,remove housing(unplug a/c power 1st ) inspect jack,wiggle it slightly see or feel a break then resodier from back side. You should be able to use the soldier already present without adding extra.

There is a possibilty that switch contacts on the footswitch jack are dirty if you are NOT using the footswitch. If you ARE using the footswitch, then an intermittent cable or static charge build up may be causing this.

Using the CORRECT footswitch for this model, you just plug it into the footswitch jack. You MUST use the correct one for the model.

The P803 is designed to work with the "Valvestate" and Tube amps. I don't think it is compatible with the Haze40 since they have an optional 4 button footswitch so the optional one would necessitate different interface than the P803.

Only 6 wires are used by the amp. Tie the brown wire to the metal frame to act as shielding if anything. You will probably find that the brown wire either connects to the shell of the connector or to nothing.

Surge protector would NOT have protected it so don't kick yourself. If you had your footswitch plugged into the amp, the surge may have ruptured components in the circuit. Most likely are components on page 2 of the schematic in the upper left corner associated with the channel selection, C77 and TR1 would be first suspects. Deeper into the circuit is the channel switch chip IC9.

A voltmeter test of the FS_B input from the footswitch to verify that with the footswitch disconnected that this approaches 5 volts is first step. If it doesn't then the three components mentioned should be tested in the order I mentioned them. If it does go to nearly 5 volts, then IC9 is likely the culprit... it is a DG212 analog switch chip. It is readily available from DigiKey.com and others... in several different type packages. If yours is surface mount, you need to find someone with the proper tools to change the chip.

Here is link to schematic: http://elektrotanya.com/marshall_mg50dfx_sch.pdf/download.html

The footswitch should be a 1/4 inch stereo type (TRS) plug to fit the footswitch jack of the MG250FX. It is a three wire connection.

The plug is a 1/4 inch STEREO type plug. Readily available at Radio Shack and many online sources. It will have three connections commonly known as TRS (Tip-Ring_Sleeve).