Flange or chorus is stuck on - Marshall MG100HDFX 100-Watt Amplifier Head

It's a Line 6 and probably requires a software update from Line 6.

Can't find a manual but can still explain. Delays, chorus, flangers, and reverbs are all the same effect except the different names of them will allow you different adjustments. Chorus usually has a width control which controls pitch shifting. Flangers and delays will have a feedback control which simply means, how many times you hear the echo. On reverb units, room size means how long of echo(even though it;s short) you want. Delay is the same with much longer echo, feedback is the same as on flangers except the flangers time is very short meaning the effect is at almost the exact time resulting in feedback causing a metalic sound. I probaly just confused you but good digital delays usually have all the features and will usually do all 4 effects depending on how you set them. If you want delay, set width on 0 and adjust time and feedback. For flanging, adjust width and speed and feedback. Chorusing, adjust time, width, and speed. Reverb, adjust time, set width on 0, and feedback. I see it has a level(mixture, how much effect you hear), and a replay(feedback, how many times you hear it), and a delay knob,(how long the echo will be) The range/mode switch allows for settings of diferent time lengths and INF setting allows for infinite repeat. Hope this helps.

Sounds like a resister is bad..

It sounds like the bypass contacts on the pedal are not working... this may be right in the pedal switch itself. With unit in off position, use an ohmmeter to check continuity between in and out cable tips.

I don't know what you mean by "DC Brick"...

The MXR Stereo Chorus unit requires a special 18 Volt power adapter. The common 9 volt pedal power adapters will NOT work with this device. If you have batteries in the unit, when you plug in an incorrect adapter, the unit disconnects from the batteries and the caps discharge so the light will fade.

You will need to use: ECB-004 18-volt AC Adapter Best to use the manufacture's exact device for this one.

SING THE FIRST VERSE OF THE SONG, THEN PASTE THE CHORUS, SING THE SECOND VERSE OF THE SONG THEN PASTE THE SECOND COURSE.

Who could even guess what musical instrument you are talking about...

BUT I will say that if it is a device with a chorus setting that uses CCD (charge coupled device delay line), there COULD be a problem with the device. This would be a job for a service shop for the unit.