Boss Mt 2 Metal Zone Effects Pedal - Answered Questions & Fixed issues

Personally I recommend the following set up:

Distortion>Effects>Compression/Noisegates/Sustain

This will ensure that the signal won't have any odd hiccups due to an odd pedal setup. But if you play around with different orders, you can end up with some very interested sounds.

Battery is not the problem. It could be transistors, IC, elco etc. It must be checked. This electronic parts, could be almost breakdown. At the beginning of the device is turned on, it work fine, but after a while it became hot, then the value is changed, then the circuit was not working. Can also occur on the DC input, the diode and the elco (D006,C019,C40,C41). View image. See the full diagram here : Boss MT 2 Metal Zone distortion pedal schematic .

Which Line 6 power supply? If you look at the specs stamped into the L6 supply you should see the voltage, current capacity, and polarity (if DC). Polarity would have a symbol showing an inner post and outer shell and indicate which is positive....referred to as positive or negative tip. Let me know what these specs are and I can have a better idea of what may have happened. Sounds like it burned out a protection circuit designed to protect the pedal from incorrect power applied. Will it still work with a battery?

Are you using battery or AC adapter for power?
Most pedals won't allow you to use both. Check that there is no battery installed if you're going to plug it in. If you are using a battery, Some pedals won't light an LED on battery power.
If problem persists, your pedal may be DOA

Electronic failure... open and look for bad soldering AND circuit board cracks under a bright light.

The battery is connected via plugging in the input guitar cable ( a seperate contact is made at the jack). Sometimes this can be broken. Usually this failure is caused by someone stepping on or yanking a cable and the solder is broken at the jack/board attachment. This can be the input jack OR the power jack. Occasionally the circuit board or the traces on it are cracked, requiring jumpers to be installed on the board. In any case, open the pedal and look for these problems.

If you are running on battery, replace the battery. The batteries tend to recover a bit and will operate the unit for a brief period

Make sure you are NOT using a TRS (stereo or three conductor cable) type cable. PLugging into the input should turn the pedal ON, not off. The switch on the jack may be broken or soldering to the circuit board may be broken OR worst case, there is a crack in the circuit board.

From the user's manual:

The Check light lights when the effect is on. It ALSO is a battery indicator and when it gets dim, you need to replace the battery if you are not using an adapter.

If it won't go OFF when you try to turn it off, then the switch has probably failed or wiring to it has failed. In this case, service is required.

The first thing I would do would try a 9V AC Adapter to rule out a battery issue completely. But if you have changed the battery already, this shouldn't be the issue. Does the red light come on at all? The next thing I would check involves removing the back cover of the pedal and making sure the input/output jacks are okay. Do you see any hanging wires, loose solder, or smell a burnt smell? If you have only had this pedal for a few months, you may be able to send it back to BOSS for replacement under your warranty.

There is one of two possible problems... either may be the one causing the problem:

1. The on/off switch has excessive "contact bounce". You Might be able to put some CRC226 into the switch if it has someplace you can squirt the stuff in, otherwise the switch will have to be replaced. This is probably the most likely cause of the problem. CRC226 is available at Home Depot in electrical dept. Make sure it is the 226 as there are other products there.

2. The power connector is loose...ooften the soldering gets broken from the board or the adapter cable is not seated or worn and vibration causes intermittent connection. Try running on a battery to see if the problem changes. One has to open the pedal to effect repairs of this nature.

There is a switch contact that connects the battery when you unplug the AC adapter. These commonly get sprung and cease to make contact leaving the battery disconnected when adapter is unplugged, resulting in no power. Verify the battery is being connected and see if the unit works properly. If so the adapter is either the wrong one or defective.
In other words, there may be two problems.

Try the obvious stuff first.

1. Check that it has a battery in it and it is installed the right way round.
2. Only use top quality batteries (Duracell Ultra or equivalent) do not use re-chargeables as they don't achieve adequate voltage.
3. If you are using a mains adapter try a battery instead as the adapter may be faulty (or vice versa)
4. Some effects pedals will not switch on without a jack plug in either the input or output socket (or both)
5. If none of that works it is probably faulty - take it back to the shop and ask them to replace it or prove it works

Check your power adapter or battery if you are using a battery.

hello i repaired 1 of these last year if you open it up you may find that 1 of the diodes has blown change it, but you may have to change the 3 long transistor as well also look for any dry joints

regards
shaun

Download and print it here:

http://www.bosscorp.co.jp/products/en/_support/om.cfm?ln=en&dsp=0&iCncd=292&iStcd=4

This is a simple problem. The input jack is a "stereo" type which we call TRS for tip-ring-sleeve meaning there are three connections. It will involve soldering.

The way it is used with your guitar cable is that the third contact on that jack (the "ring") is used to turn the thing on because your MONAURAL guitaar cable shorts that ring contact to the sleeve completing the circuit for the battery or power cube if you are using that.

These jacks are EASILY destroyed by bending the plugged in cable a bit.

Solution: Go to Radio Shack and get a panel mounted "Stereo" jack (they may come two to a package, make sure it is the Stereo type).

Open your unit and install the jack. If the one in your pedal is a plastic one mounted on the board (those are even more fragile) see if you can't use the Radio Shack type anyway with short jumper wires to the circuit board.

If you would rather use a board mounted one, they are available from Mouser.com or DigiKey.com. You can pick out the part from teh online catalog... note that there are MANY ocnfigurations.

Normally the 12 volt supply would NOT damage the unit UNLESS it had the wrong polarity or was an AC type.

Likely damage if these were used is confined to a few small electronic components where the power copmes into the unit.

Repair the unit before putting correct supply as you could damage the correct supply if those parts failed a certain way.

use boss power supply

It is possible the pedal is DESIGNED to be used with an amplified (preamp within guitar) and yours MAY be a passive guitar. You did not tell us what guitar you have.
Many of the processors for guitars depend on having a "line level" signal and that requires that your guitar has a built in preamp.
If your guitar doesn't have a preamp in it, buy a preamp to put ahead of this pedal.