Yeks MFC-101 How-Tos page
From Fractal Audio Systems Wiki
This FAQ covers firmware versions 2.15 and earlier
Where to find the official supporting documents
The Owner's Manual and QuickStart Guide are available here.
How to learn more about MIDI footcontrollers, pedals and switches
- Read the Axe-Fx How-Tos (Standard/Ultra).
- Read the Axe-Fx II Wiki.
What's the difference between the MFC-101 and the MFC-101 "Mark II"
Cliff: "The only change is the CAT-5 connector is now an Ethercon jack. An Ethercon jack will work with either a CAT-5 cable or an Ethercon cable." Source
How to connect and power it
Use the supplied 9VAC adapter to power the MFC-101 directly. According to Fractal Audio 9VDC will also work, but DC doesn't work as well over long distances.
You can use "MIDI phantom power" instead. This means that power to the MFC-101 is carried through the MIDI cable. Requirements:
- Use a 7-pin MIDI cable between the MFC-101 and the Axe-Fx. Alle pins must be wired; pins 6 and 7 are used to carry power.
- Connect the power supply for the MFC-101 to the Phantom Power input at the rear of the Axe-Fx (the Axe-Fx doesn't provide power itself, it needs the power supply!).
A good MIDI cable is required. To receive tuner and tempo data all pins of a 5-pin MIDI cable must be connected. A lot of MIDI cables just have 3 pins connected. And another thing: make sure the connector that goes into the Axe-Fx is long enough. If it's just a little short, tuner and tempo data will not be transmitted. Low-cost cable often are not properly shielded, resulting in audible data transfers.
With the Axe-Fx II a CAT5 cable can be used instead of a MIDI cable, connected to the Rj45 port. This:
- provides power to the MFC-101 without the need to connect an adapter to the Axe-Fx II
- transmits MIDI messages between the Axe-Fx II and MFC-101
- carries tuner and tempo information to the MFC-101
- switches off the MFC-101 when the Axe-Fx II is switched off.
- supports simultaneous use of Axe-Edit and MFC-101 natively, without the need for MIDI merging through additional software or hardware.
- Use Edit > MIDI to configure the MFC-101 for use with either a MIDI or Rj45 cable connection.
- When configured for the use of a CAT-5 cable (Edit > Setup > "Expansion"), the MIDI-OUT port on the MFC-101 won't pass data anymore. You can't use both ports simultaneously. Source
- When using a CAT5 cable, DO NOT CONNECT the AC adapter, or damage can occur.
- A propietary communication protocol is used for bidirectional communication and phantom power. The internal PSU for the MFC-101 will also support an expansion module for the MFC-101. Source1 Source2 Source3
- Wikipedia: CAT5, Rj45.
More information about connecting and powering the MFC-101 in chapter 2 of the Owner's Manual.
Cliff: "Do NOT attempt to extract power from the MFC connector. It is only rated for 1A and if you burn out the port we won't cover that under warranty." Source
Forum member Chrisallen8888 made videos on how to setup the Axe-Fx II and the MFC-101 for basic use as well as using expression pedals. The videos are posted on his Katsu Kuri Media Blog page.
How to upgrade its firmware
Go to Edit > Setup to see the currently loaded firmware version.
You can download the latest firmware from Fractal Audio Support.
To upgrade using a MIDI interface:
- Disconnect the MFC-101's MIDI-OUT and CAT-5.
- Connect MIDI-OUT on the MIDI interface to MIDI-IN on the MFC-101 using a 5-pin MIDI cable. Make sure the MIDI cable is firmly inserted in MIDI-IN on the MFC-101.
- Connect the MFC-101's wall wart.
- Power on the MFC while holding down footswitch #1. This enters the Firmware Update mode.
- Start transmitting the firmware file using a MIDI utility such as MIDI-OX (Windows) or Snoize SysEx Librarian (Mac). The MFC-101 will display the completion percentage.
- Wait for confirmation on the MFC display.
- Power on the MFC-101.
- Reconnect the required cables.
To upgrade using the Axe-Fx II as a USB-to-MIDI MIDI adapter: Source
- Connect the Axe-Fx II to your computer, through USB.
- In the Axe-Fx II's MIDI menu, set SendRealtimeSysex to NONE, and UsbAdapterMode to ON.
- Power down the Axe-Fx II.
- Connect the Axe-Fx II's MIDI-OUT to the MFC-101's MIDI-IN with a 5-pin MIDI cable.
- Power on the Axe-FX II.
- Power on the MFC-101 by reconnecting Cat5 cable, while holding down footswitch 1 (enters firmware update mode).
- Send the new firmware with a MIDI librarian, such as MIDI-OX or SysEx Librarian, from your computer to the Axe-Fx II.
- Power down the MFC-101 and Axe-Fx II.
- Remove the MIDI cable.
- Power on the Axe-Fx II.
- In the Axe-Fx II's MIDI menu, set SendRealtimeSysex to the desired value, and UsbAdapterMode to OFF.
An upgrade may require you to reset the MFC-101 to its factory settings. If so, it will be stated in the release notes. To reset the MFC-101, power on while holding switch #11. Note: this will cause you to lose your configured settings! You can save these on forehand and restore these afterwards.
MIDI utilities may need to be configured to work "slowly" in order to perform a successful upgrade. For example, in MIDI-OX set Low Level I/O Buffers to 256 or 128 (size) and 16 (number), Milliseconds Between Buffers to 60 ms, and make sure the Delay after F7 setting is ticked. Use View > Sysex to bring up the Sysex view window, then go to Sysex > Configure to configure the buffers. Also verify that the options MIDI FIlter and Pass Sysex are ticked.
If you're experiencing problems, open the Utility > Preset page on the Axe-Fx, because this makes sure the Axe-Fx is not sending out stuff which could interfere with the update process.
More information in this Wicked Wiki thread.
How to find the firmware release history
The firmware release history is included with each firmware file.
How to backup or restore settings
Go to Edit > Setup > Sysex Data. See page 68 of the manual.
How to reset it to factory default settings
Reboot with switch 11 held down, select "MFC-101" and pressing Enter. See par. 12.5.22 for more information. Par. 14.5 lists all factory default settings.
How to get started
Read the Quick Start guide to get started.
Make sure you choose your Axe-Fx model correctly.
You may need to reset the Axe-Fx to its factory default settings. That ensures that controller numbers are set correctly and that tuner and tempo information is transmitted to the MFC-101. If you reset the Axe-Fx, be sure to check all important system settings and adjust where necessary (Global, I/O, Tuner).
Make sure to:
- set the MFC-101 to the right configuation (Standard, Ultra, Axe-Fx II, None)
- tell the MFC-101 whether you're using a MIDI or CAT5 cable (connection port: MIDI or EXPANSION).
How to adjust the display contrast
You can adjust the contrast of the display in Edit > Setup.
How to make the LEDs less bright
Put small bits of painter's tape on top of them. Or use this smart and simple solution by Toadfish.
How to program it
You must program the MFC-101 using the Edit menu on the device itself. There's no software editor currently.
Note: firmware 2.13 and later enable you to instruct the MFC to wait for a "long" press instead of a short one, to enter Edit mode when pressing Edit. This prevents accidental entering of Edit mode during live use.
How to sync the MFC-101 to Axe-Fx and Axe-Edit preset switching (TotalSync)
If you switch presets on the front panel of the Axe-Fx, the MFC-101 can also switch along. The same goes for preset switching in Axe-Edit. You can control this feature (TotalSync) through a parameter in the MIDI menu.
TotalSync doesn't work in Song and Set modes, and custom MFC-101 Tx Map or Axe-Fx II preset remapping (for example to support scenes) are not supported.
To show Axe-Fx's tuner in the MFC-101 display and let the Tap Tempo LED blink in the correct tempo, the MFC-101 must be in Axe-Fx Mode. Also, use a 5-pin MIDI cable (with all pins connected!) for bidirectional communication or a CAT5 cable with the Axe-Fx II. On the Axe-Fx set the parameter Send Realtime Sysex (I/O > MIDI) to All.
How to use a single switch for Tap Tempo and Tuner
You can combine the Tap Tempo and Tuner functionality. Holding Tap Tempo will enter the Tuner mode. Use Edit > Setup to set this up. This does NOT work with external switches.
Regarding an IA set to Tap Tempo: the switch type will be set automatically.
Regarding an IA set to Tuner: when the tuner is active, it's still possible to engage/bypass other effects, switch banks, presets and songs etc.
How to program the switches
First choose the desired Bank Size (Edit > Setup, see below). Decide whether you want to use Axe-Fx Mode or not (Edit > Setup). Then use Edit > Midi to configure the IA switches.
The MFC supports 384 presets.
If you like to see how other users have configured their MFCs, read this thread.
How to assign an Axe-Fx effect or MIDI function to an IA switch
In Axe-Fx Mode go to Edit > Midi > IA and select the desired effect for each switch from the list. In Axe-Fx Mode IAs work globally (you cannot change the function of a switch per preset). Pressing an IA switch assigned to an Axe-Fx effect will display its name on the MFC screen.
If you select "None", the switch is not assigned to an effect and is available for general MIDI use (referred to as: General Use IA Switch). This lets you use MIDI commands to assign a function. You can send 2 separate MIDI CCs, a MIDI PC, and additional custom MIDI commands. Use value 127 to turn effects on, 0 to turn them off. Or select OFF to send nothing at all. General Use IAs operate global (same across all presets).
A General Use IA switch can be toggle/latching or momentary, and can be given a 7-character name. When pressing an IA the assigned name will be displayed briefly on the display.
How to know which LED color indicates what effect state
With the MFC-101 in Axe-Fx Mode:
- Red: effect is present in the preset, bypassed.
- Green: effect is present in the preset, enabled.
- Off: effect is not present in the preset.
You can disable the Red (bypassed) LEDs (In Edit > Setup set IAOffLed to Off), which works better for colorblind people.
How to learn more about expression pedals
Read this (by Mission Engineering).
How to connect, calibrate and configure an expression pedal
You can connect up to 4 expression pedal(s) to the rear of the MFC-101. Expression pedals need 1/4" TRS (stereo) cables!
Use Edit > Setup and Edit > MIDI to configure the pedals. Edit > Preset lets you override global expression pedal settings.
By default pedal #1 is mapped to CC 11 (global Output 1 volume) and pedal #2 to CC 16 (External 1). Pedals 3 and 4 default to OFF, which may not be obvious because the MFC will let you calibrate the pedals.
If there's no expression pedal connected to the MFC-101, the output volume of the Axe-Fx may be muted. To solve this, disable expression pedal #1 on the MFC-101.
Calibration: see chapter 7 of the manual. Note: it's normal for pedals not to employ the full value range (0 - 127). If your pedal only gets to 100 or so, it can still perform 100%.
Use the Beginning Value parameter (Edit > Midi) to define the state of the pedal after switching presets. "PDL" means that the position of the pedal is polled and recalled, "Off" means that the pedal is off until moved, or you can select a specific value between 0 and 127.
While you can define/limit the operational range of an expression pedal (globally or per preset), you also use the Modifier menu of effects blocks on the Axe-Fx for this purpose.
Settings in Edit > MIDI are global. If you want program a pedal to behave differently with some presets, adjust things in Edit > Preset.
In the Axe-Fx II manual it's explained step-by-step how to connect an expression pedal to the MFC-101: read this.
How to use an expression pedal to control different effects without switching presets
How to connect an external switch
You can connect additional momentary or toggle/latching switches to the rear of the MFC-101. It has 2 inputs which, when using TRS (stereo) cables, allow for 4 switches. A single switch can also be used with a TS (mono) cable but you need to set the second switch to Off.
Use Edit > Setup and Edit > Midi to configure external switches.
You can specify whether the external switch is a momentary or latching switch type.
An external switch can control a single MIDI CC, using value 0 for off and 127 for on. You can't use them for preset switching or custom MIDI stuff.
Settings in Edit > MIDI are global. If you want program the switch to behave differently with some presets, adjust things in Edit > Preset.
How to connect and configure an expression pedal with a switch
Some expression pedals have a separate switch. You can use separate connections for the pedal and the switch and configure the switch to activate an effect which then can be controlled with the pedal, such as a wah. Here's a walkthrough.
- Connect the expression pedal to the MFC using one of the 4 expression pedal inputs on the MFC. Use a stereo (TRS) cable.
- Connect the switch to one of the 2 switch inputs on the MFC (see above about the possibility to use an expression pedal input instead). Use either a stereo (TRS) or mono (TS) cable. If using a mono cable, disable the other connection of the switch in the setup menu (see below).
- Use a MIDI cable between the MFC and Axe-Fx.
- On the Axe-Fx, insert a Wah block in the preset.
- Set the FREQ or CONTROL parameter of the Wah block to the External controller (the one that's tied to to the expression pedal, see below).
- Use Damping if desired. Set PC RST to On. Keep Auto-engage Off because you will be using the switch.
- Save the preset with the Wah disabled.
- In I/O > Ctrl on the Axe-Fx, note which CC is used for the Wah 1 block (default #97).
- In I/O > Ctrl on the Axe-Fx, note which CC is used for the External controller which is tied to the expression pedal, mentioned above.
- In I/O > Midi on the Axe-Fx, verify that the External controller which is tied to the expression pedal is set to 0%.
- Make sure that the expression pedal is calibrated (Edit > Setup on the MFC).
- Make a connection between the pedal and the Axe-Fx by selecting the right CC and channel in Edit > MIDI on the MFC. Make sure you select the correct pedal input (XP1 - XP4). The CC must match the External controller's CC on the Axe-Fx (see above).
- In Edit > Setup on the MFC set the external switch to Toggle. Make sure you select the correct switch input (XS1 - XS4).
- Make a connection between the switch and the Axe-Fx by selecting the right CC and channel in Edit > MIDI on the MFC. Make sure you select the correct switch input (XS1 - XS4). The CC must match the CC of the Wah block on the Axe-Fx (see above). Set type to HDW. When using a mono cable for the switch, disable the other connection (set it to Off) to prevent MIDI problems.
- Tell the MFC the switch values for Off and On (Edit > MIDI). 000 = Off. 127 = On. If the LED works vice versa, switch the values: 000 = On, 127 = Off.
In this video James from Mission Engineering explains how to connect the switch output of an expression pedal to an expression pedal input (instead of a switch input)! Handy if you need the switch inputs on the MFC-101 for other purposes.
How to program an IA switch to toggle between two effects
Set up the switch to send a CC to an External Controller on the Axe-Fx. Assign Bypass in two effect blocks to the same External Controller. Set the Start value of one block to 100 and the other to 0. Or an example when alternating between Comp and Drive: Set one of the externals to the same CC as COMP, then use it to bypass Drive. Set the switch to COMP and you'll get RED=DRIVE, GREEN=COMPRESSOR (source: Matman).
How to program a single IA switch to enable some effects and disable others
How to activate or bypass multiple effects simultaneously
This is a trick that lets you assign multiple effects to one switch. That's because a block that you won't typically use (and doesn't take up many CPU-cycles) can serve a surrogate for any number of Axe-Fx blocks in Axe-Fx Mode (source: Matman).
- Pick a surrogate such as VOL4 or FILTERx, set to NULL. On the Axe-Fx go to I/O > CTRL and assign the same MIDI CC to your surrogate and all of the effects you want assign across the single footswitch.
- Place the surrogate effect block (disconnected) in every preset that has your target block(s).
- Set its bypass state and that of the assigned effect(s) to the same initial state
- Assign the surrogate to the Axe-Fx IA in the MFC-101.
Now you have've got bi-color-LED-enabled control over different multiple blocks across different patches from a single IA switch.
Alternatively: assign the same CC (or an external controller) to all desired effects. But this way you won't get multi-color LEDs.
How to select an effect within a group (Switch Links)
The Switch Links setting lets you define a group of switches. Within that group only one setting can be active, so selecting one switch will automatically disable the others within the group (mutually exclusive). There's a maximum of two groups and 5 switches per group. Switch Links is particularly useful to switch channels on an external amp (see separate topic). It's also possible to press the active effect to disable it.
How to access scenes
The MFC offers special support for Axe-Fx II preset scenes. You can assign an IA switch to activate any of the eight scenes within a preset directly. Or you can configure a switch to increment or decrement the scene. You can also use general MIDI to switch scenes.
How to use an external switch to control Tap Tempo
- Connect the switch to one of the switch inputs on the MFC (1+2 or 3+4). Use a TS or TRS cable, depending on the switch. When using a TS cable disable the second switch (XS2 or XS4) on the MFC.
- Set the switch type in Edit > Setup to Toggle or Momentary, depending on the switch.
- In Edit > MIDI > XS set the switch to control CC #14.
- In Edit > MIDI > XS set the switch to TypTOG. The value is misleading, this also applies to momentary switches.
- If desired, set the onboard IA switch to Tuner instead of Tempo.
How to use the Global Preset feature
Set the Global Preset feature to ON (off by default) in Edit > Setup and assign a preset to it (Edit > Preset). Now this preset can be recalled at any time by pressing a preset switch TWICE. Global Preset works only with presets, not IA switches (CCs).
Turn off this feature if you want to be able to recall a preset as it was saved by pressing a preset switch a second time (see Panic switch topic).
The Global Preset can also be set to "Backtrack", see below.
More information in this Wicked Wiki thread.
How to return to a previous preset (backtracking)
Backtracking: a second stomp on a preset switch will load the previous preset. You can set this per preset (Preset menu) or configure Global Preset to act as Backtrack ("BAK").
How to assign an alternate preset per preset
A second stomp on a preset switch lets you activate another preset, which can be different for each preset. This is an alternative to using a common Global Preset or Backtracking. You can set this in the Preset menu.
More information in this Wicked Wiki thread.
You use Alternate Preset in combination with Axe-Fx Scenes.
How to create a panic (revert) switch
It can be handy to be able to reset your current preset to its saved state, just by pressing a preset switch a second time. This will send the MIDI Program Change again to the Axe-Fx and recall the preset as it was saved. This requires that:
- Global Preset on the MFC-101 is OFF (otherwise the second press would activate it) and
- Ignore Redundant PC on the Axe-Fx (I/O > MIDI) is OFF.
Note that recalling a preset this way causes a short audio dropout.
More information in this Wicked Wiki thread.
How to arrange presets for use in songs
Use the Song and Set Modes (names on the MFC start with a "S"). You can use up to 15 presets per song (depending on the Bank Size setting). The MFC supports up to 100 songs. Preset switches in Songs can be set to OFF.
You can also use Song Mode to circumvent a limitation of Preset Mode. In Preset Mode banks have no names, you have to remember which presets are in numbered banks. However, if you assign presets to songs in Song Mode, maintaining the bank structure, you can give them names.
Sorting a Song or Set list is not possible currently.
An alternative to Song Mode: use Axe-Fx Scenes.
How to use MFC-101 presets instead of Axe-Fx presets
In Axe-Fx Mode the MFC-101 always syncs the IA switches with the state of the effects in the Axe-Fx preset, and autom. displayes the preset names, stored in the Axe-Fx. To create variations of an Axe-Fx preset with different effect states, disable Axe-Fx Mode, select a preset, enable/bypass the effects on the MFC-101 and store the preset on the MFC-101 (Edit > Preset). MFC-101 preset names in Preset Mode are preced by a "P" (instead of "X"). Using MFC presets instead of Axe-Fx Mode means the MFC-101 becomes the main control center instead of the Axe-Fx.
How to change the number of presets per bank (Bank Size)
The MFC-101 defaults to 5 presets per bank. It can be set to any number of switches. Use the parameter Bank Size (Edit > Setup) to change this, depending on how many IA switches you want to be accessible directly without needing to press Reveal. Note that this also influences the layout of the Song and Set modes.
When using Bank Size "0" or "1", use the Up/Down switches to scroll through banks and automatically load the preset which has been set to Autoload (see Bank Style).
The selected Bank Size also influences Song and Set Mode's layout.
Note that preset switches always start on the bottom row. Currently this can't be changed.
Currently it's not possible to limit the operational range of banks for performance purposes.
How to determine what happens with preset selection when changing banks (Bank Style)
Use the menu item Bank Style (Edit > Setup) to instruct the MFC-101 what to do when changing banks:
- Automatically load the first preset of a bank ("First").
- Automatically load the preset at the current position in the bank ("Current", default setting).
- nothing ("None").
If Bank Style is set to "None", banking up/down will show the bank number and the preset range within the bank (Smart Banks).
The speed of scrolling through Banks, Songs and Sets cannot be adjusted currently.
How to limit the number of available banks or songs for live use
When playing live you may need access to just a subset of all available banks. The Bank/Song Limit parameter lets you define the range of this subset. This prevents scrolling through bamks/songs you don't need. Available in firmware 2.13 and later. Also, you may want to stop scrolling through banks/songs after reaching the first or last bank/song (no "wrapping around"). The Bank/Song Wrap parameter lets you enable/disable this.
How to (not) retain effect states when switching presets (aka "stompbox mode")
You may want IAs to "carry over" their active state when switching presets. This is controlled through the Global and Send w/Preset parameters. After a factory restore Global defaults to Off, and Send w/Preset to On.
These parameters works with "general use" IA switches only. IA switches set to Axe-Fx functions will always adhere to their saved state in the recalled preset.
See the table in par. 5.2.5 of the Owner's Manual for a helpful description of how these two parameters work together exactly!
Regarding external switches: the parameters TyHDW and TypTog control whether an external switch carries over its active state when switching presets. External latching switches: if set to TypHDW, they carry over their state because the MFC-101 polls them after having switched presets. Use TypTOG to prevent polling but this may cause the LED on the external switch to lose sync. External momentary switches: if set to TypHDW, they operate as a momentary switch and retaining states is irrelevant. Use TypTOG to make a momentary switch operate as a latching switch (the switch won't retain its state).
How to create a boost/lead switch
Read the Axe-Fx How-Tos. Configure an IA switch to "None" (no Axe-Fx effect), then assign the required CC message(s) and values (Edit > MIDI).
You can make presets enable the boost automatically: in Edit > Preset make sure that the boost switch is set to On.
Alternatively, use the Axe-Fx II's Scenes feature.
How to organize your lead tones
- If you have a single solo preset, you can use the Global Preset feature: press any preset twice to get to that solo preset.
- If you have various solo presets, you can use the Alternate Preset feature: press a preset switch twice to get to the "alternate" preset for that switch, which can be a specific solo preset.
- If you use Song Mode, create solo presets and assign them to songs where needed.
- If you prefer not to use presets but use IAs instead, you can configure a switch to change the state of two effects (without an external). If 2 is not enough, you can use custom MIDI to configure more, but it's harder to do so.
- You can assign a single CC to multiple effects on the Afx (I/O > Ctrl), and change them all with one switch.
- Use the Scene feature (Axe-Fx).
How to turn an IA switch into a preset switch
Make sure that the switch isn't assigned to an Axe-Fx effect (Edit > Midi). In Edit > Midi > IA Switch scroll to the PC page, set it to On and specify the Program Change number. Set the Switch Type (Edit > Setup) to the desired state for the LED behavior. This works only for onboard switches, not with external switches.
How to change additional effect settings
MFC-101's Internal CCs can be used to change effect parameters without the need to assign switches. Internal CCs can be given names. Use Edit > Setup and Edit > MIDI.
How to operate the Looper with the MFC-101
Firmware 2.11 added Looper Control Mode. This mode is enabled by pressing and holding the Reveal button. In Edit > Setup you can select if this requires short or long pressing-and-holding. You can also disable Looper Control Mode altogether. More information: MFC-101 Looper Control Mode Mini Manual.
How to keep the Looper running when switching presets
These are the requirements to keep the Axe-Fx Looper playing when switching presets:
- the preset you're switching to must have a Looper block
- make sure the Record switch is set to non-Global and Off
- make sure the Play switch is set to Global.
How to expand the functionality of the MFC-101
Apart from using expression pedals and external switches you can connect an additional MIDI controller to the MIDI IN port on the MFC-101. To have it recognize incoming MIDI messages, select the correct MIDI channel for the added device in Edit > System. To prepare the MFC-101 for incoming Program Changes enable that setting in Edit > System too. Upon receiving a Program Change the MFC-101 will sync its display.
Tip: a Tech 21 MIDI Mouse is a small MIDI foot controller. It's battery powered (5-pins MIDI phantom power or a power supply is also possible). Quite useful to expand the preset switching capabilities of the MFC-101.
Another expansion possibility is the use of a MIDI utility such as MIDI Solution's Event Processor or Bome's MIDI Translator. These devices convert MIDI messages, such as a specific MIDI CC, into other messages like a PC. This lets you expand MIDI control.
How to use the MFC-101 to switch channels on my amp
The MFC-101 cannot do this on its own (unless you have a MIDI-controlled amp) because it has no relay switches. But you can use MIDI to control an external MIDI switcher for this purpose. Check this thread for solutions.
How to get labels for the switches
There are several label suppliers and solutions to be found on the Fractal Forum.
Commercial suppliers are:
How to deal with error messages
Par. 14.2 of the manual lists all MFC-101 error messages and solutions.
How to solve the "Waiting for tuner" issue
If the Axe-Fx Tuner is not on its first page on the Axe-Fx, then activating the Tuner on the MFC-101 generates the message "Waiting for tuner". Also, verify that SendRealtimeSysex in the AQxe-Fx's MIDI menu is set to All or Tuner.
How to repair a MFC-101 that won't scroll down anymore
Switch #1 may be stuck. Depress it a number of times. Source
Testing the LEDs
The MFC-101 has a test mode. Press Edit followed by Reveal.
How to solve stuttering audio, pops, clicks or slow respons when switching presets
In some cases operating the MFC-101 can create noise. Here are causes and solutions:
- Make sure you have the latest firmware loaded (both Axe-Fx and MFC-101). Preset switching has improved with firmware upgrades.
- Change the Axe-Fx's MIDI channel (I/O > MIDI) from Omni to 1.
- Placing the MFC-101 near powered speakers, or on top of the Axe-Fx, may result in popping noise when operating the switches.
- If you assign the Vol Decr/Inc commands to IA switches or external switches, you may notice clicks or pops when switching presets. Solve this by configuring them to send nothing else.
- If you hear a ticking or clicking sound that's in sync with the tap tempo light, there's interference from your MIDI cable into your guitar or guitar cable. It's the sysex data being sent. Make sure you route the MIDI cable away from anything that it may interfere with or use a CAT5 cable. Or switch off "Send Realtime Sysex if you don't need to use the tuner and the tap tempo light. Source
How to know what Axe-Fx stuff can be controlled through MIDI CCs
On the Axe-Fx go to I/O > Ctrl to see the list of MIDI CCs.