• Fast, dense chords are played
• Large amounts of streaming MIDI data fill up the U-20's MIDI buffer
  
• The setting Rx SysEx = ON

• If the MIX OUT jacks are being used, setting this switch to FIXED will set the volume output at maximum level regardless of the position of the front panel Volume knob. Setting this switch to VARIABLE will allow you to regulate the volume using the VOLUME knob
  
  
• The switch has no effect on the headphone volume. When using headphones, you can always adjust the volume using the VOLUME knob
  
  
• The switch has no effect on the sound that is being output from DIRECT OUT and you will not be able to regulate the volume using the VOLUME knob
  
  
• Always turn the power off before changing the setting of this switch

Test  #1  [ JUMP ] + [ BANK 1 ]    LCD Contrast Test (Adjust level by using the Pitch Bender)
Test  #2  [ JUMP ] + [ BANK 2 ]    LED Test (Adjust speed by using the Pitch Bender)
Test  #3  [ JUMP ] + [ BANK 3 ]    Internal RAM Test (Also shows the internal battery voltage. Cool!)
Test  #4  [ JUMP ] + [ BANK 4 ]    RAM Card Test (Also shows the RAM Card battery voltage. Cool x 2!)
Test  #5  [ JUMP ] + [ BANK 5 ]    PCM Card Test (See Notes Below)
Test  #6  [ JUMP ] + [ BANK 6 ]    Internal PCM ROM Test (Outputs letters A - F if OK)
Test  #7  [ JUMP ] + [ BANK 7 ]    Key + Button + Pedal + PCM Card Insert Tests (DP-2 Pedal)
Test  #8  [ JUMP ] + [ BANK 8 ]    A/D Converter Test + Visual Aftertouch Tests (See Notes Below)
Test  #9  [ JUMP ] + [ NUMBER 1 ]  Control Sliders + External Input Tests (C1, C2, EV-5 Pedal)
Test #10  [ JUMP ] + [ NUMBER 2 ]  MIDI I/O test. Connect MIDI IN to MIDI OUT w/cable. Press [ ENTER ]
Test #11  [ JUMP ] + [ NUMBER 3 ]  Sound Test #1 (Requires Connecting An Oscilloscope - See Service Notes)
Test #12  [ JUMP ] + [ NUMBER 4 ]  Sound Test #2 (Requires connecting an oscilloscope - See Service Notes)
Test #13  [ JUMP ] + [ NUMBER 5 ]  DAC MSB Adjustment (Requires connecting an oscilloscope - See Service Notes)
Test #14  [ JUMP ] + [ NUMBER 6 ]  Effect Test. Press and hold any key for more than 0.5 seconds
Test #15  [ JUMP ] + [ NUMBER 7 ]  Memory Initialization (* * DESTRUCTIVE! * *)
Test #16  [ JUMP ] + [ NUMBER 8 ]  Factory Data Load from an M-256E or M-512E RAM Card (* * DESTRUCTIVE! * *)

  Notes:
  a) [ JUMP ] + [ BANK ]  -or-  [ JUMP ] + [ NUMBER # ] indicates pressing both buttons simultaneously
  b) "PCM Card Test" will only work with PCM Cards SN-U110-11 (in Slot #1) and SN-U110-01 (in Slot #2)
  c) "A/D Converter Test" displays Pitch Bender and Modulation levels when using the Pitch Bender
  d) See page 10 of the U-20 Service Notes for a detailed descriptions of all Test Modes
  e) "Visual Aftertouch Test" shows how lame your U-20's Aftertouch can really be. I was only able to get 
     mine up to the 20 - 25 range... nowhere near 127... and I was really pressing hard. There is an easy and
     inexpensive modification at the SuperSynth U‑20 DIY Page allowing a more responsive Aftertouch

Test  #1  [ JUMP ] + [ EDIT ]    LCD Contrast & LED Test (△ VALUE ▽ = Contrast Control)
Test  #2  [ JUMP ] + [ DATA ]    SRAM Test (Also shows the internal battery voltage. Cool!)
Test  #3  [ JUMP ] + [ EXIT ]    PCM Card Test (See Notes Below)
Test  #4  [ JUMP ] + [ ENTER ]   Internal PCM ROM Test (Outputs letters A - F if OK)
Test  #5  [ JUMP ] + [ ◅ PART ]  Switch Test (Press panel switches in any order)
Test  #6  [ JUMP ] + [ PART ▻ ]  MIDI I/O test. Connect MIDI IN to MIDI OUT w/cable. Press [ ENTER ]
Test  #7  [ MARK ] + [ EDIT ]    DAC MSB Adjustment (Requires connecting an oscilloscope - See Service Notes)
Test  #8  [ MARK ] + [ DATA ]    Sound Test #1 (Requires Connecting An Oscilloscope - See Service Notes)
Test  #9  [ MARK ] + [ EXIT ]    Sound Test #2 (Requires connecting an oscilloscope - See Service Notes)
Test #10  [ MARK ] + [ ENTER ]   Effect Test (Connect To Amp. Press and hold VALUE △ for more than 0.5 seconds)
Test #11  [ MARK ] + [ ◅ PART ]  Memory Initialization (Press VALUE △  * * DESTRUCTIVE! * *)
Test #12  [ MARK ] + [ PART ▻ ]  Factory Data Load (* * DESTRUCTIVE! * *)

  Notes:
  a) [ JUMP ] + [ *BUTTON* ]  -or-  [ MARK ] + [ *BUTTON* ] indicates pressing both buttons simultaneously
  b) "PCM Card Test" will only work with PCM Cards SN-U110-01 (in Upper Slot) or SN-U110-01 (Lower Slot)
  c) See Page 9 of the U-220 Service Notes for detailed descriptions of all Test Modes

Test  #1  S-RAM CHECK
Test  #2  LCD CHECK
Test  #3  KEY & LED CHECK
Test  #4  BATTERY CHECK
Test  #5  MIDI CHECK
Test  #6  WAVE ROM CHECK
Test  #7  ROM CARD CHECK
Test  #8  DAC OFFSET ADJUSTMENT
Test  #9  DAC MSB CHECK
Test #10  SOUND CHECK
Test #11  OUTPUT CHECK

   To proceed to the next test, press the [ DEC ] + [ INC ] buttons simultaneously
   To return to the previous test, press both [ ◅ ] CURSOR [ ▻ ] buttons simultaneously

Note:
  See Page 8 of the U-110 Service Notes for detailed descriptions of all Test Modes

• When removing the keys from the keyboard bed, write down an ordered list of the numbers which are embossed on each key. The white and black keys all have numbers and/or letters on them. The numbers are located at the top rear (i.e. CF11, 1‑3, D11, 1‑1, EB12, CF12, etc...). You will need a list to know the correct sequence when reassembling. I have created an image which shows the correct sequence at this link
  
  
• When removing the keys from the keyboard bed, keep the flat springs in order so you can place them back in the exact location as you found them. Take care not to bend them out of shape. These do not have numbers on them :^(
  
  
• Page 3 of the Roland U‑20 Service Manual has a great step‑by‑step guide detailing the proper way to remove and replace keys
  
  
• I found the best way to use this cleaner is to pour it over the keys into a pail and cover it with a large plastic bag then seal it with a large rubber band. Although the smell is minimal even without covering it, this step completely eliminates any chemical odor. Everyone in the house will thank you
  
  
• An online visitor has discovered that leaving the pail of solution and keys in the sun all day will actually speed up the dissolve process. His weights were dropping out by mid‑afternoon
  
  
• The red goop on my keys was not a drippy liquid but it was not a solid either. I'd say about halfway... like a slightly melted bar of chocolate. I left the keys in the solution for exactly 72 hours. Depending on how solid or liquidy your red goop is, 72 hours may be too long. After 48 hours, all of the goop was dissolved around the sides of the weights and the key could have been washed with water, dried and then have new epoxy applied. I waited longer for the weights to fall out. The weights never did drop out on their own as reported by others who have tried this. I still had to do extra work to remove each weight
  
  
• I only submerged the white keys. The black keys used a different epoxy which was an off‑yellow color. It was very solid when poked with a needle and none had any red goop problems. 25 less keys to worry about. Yay!
  
  
  
  
• When reattaching the weights, I recommend using Loctite Epoxy Instant Mix™ (UPC#: 079340686205). Only mix enough for 10 weights at a time or it will harden too quickly. You don't need to completely surround the weight with the epoxy as Roland did. They used a weaker epoxy (obviously!) and thus had to overspread it. Using a toothpick to apply two small "pencil eraser sized" dabs at the front and back will work fine (see image below). This is extremely strong stuff and perfect for gripping something like keys which see a lot of action. In the event you didn't notice when you removed the weights, the four dimples face inward and touch the key. My guess is these were designed to keep a small gap in‑between the weight and the key to increase the height of the epoxy layer for a stronger bond. Warning: Don't get any of this shit on your fingers or on top of the keys. Even when unmixed, the liquid components in the Loctite Epoxy are unforgiving. From experience, I always use latex gloves when using this stuff. No matter how hard you try to keep clean, you will always end up getting some on your fingers
  
  
• Alternate Method Nixed
  • One comment I read online suggested arranging all the keys on a large cookie sheet with the weights facing up. Pour just enough solution in the channel of each key to cover the weight. The advantage of this is that you only need to use a small amount of solution. This method may be better suited for use with sodium hydroxide or Drain‑O because I tried it on one key as a test it and it did not work at all for me
    • When the red goop started to dissolve, it formed a jello. I kept adding more solution and the jello got thicker and thicker. After 48 hours I just gave up on it because the red goop was not dissolving
    • The playing surfaces of the keys are not cleaned at the same time as compared to submerging
    • Covering the entire cookie sheet to help cut down on the chemical odor is difficult
      
      
      

      Two small dabs of Loctite Epoxy Instant Mix™
      were used to reattach the key weights

    Dimensions
       Length: 34.6mm (1.36 inches)
        Width: 16.0mm (0.62 inches)
       Height:  2.2mm (0.08 inches)
       Weight:  0.60g

• Connect U‑220 MIDI OUT to U‑20 MIDI IN
• Connect U‑20 MIDI OUT to U‑220 MIDI IN
• Initiate a "Bulk Dump All" on the U‑220
• The U‑220 LCD will display "Transmitting Sysex."
• The U‑20 LCD will display "Receiving Exclusive."
• All Patches and Tones have been transferred from the U‑220 to the U‑20

• The U-220 and U-110 are unable to use M-256E or M-512E RAM Data Cards to store Patches and Tones
• Several owners report that the U-110 is much noisier than the U-20 and U-220
• The U-20 has two 1/4" input jacks for connecting an EV-5 Expression Pedal and a DP-10 / DP-2 Hold Pedal
• The U-20 and U-220 have 2 PCM Expansion Card Slots. The U-110 has 4 PCM Expansion Card Slots
• The U-110 has a different DSP effects structure than the U-20 and U-220
• The U-110 and U-220 have more assignable outputs than the U-20
• The U-110 has a lower sample playback rate than the U-20 and U-220
• The U-110 has 2MB Internal ROM. The U-20 and U-220 have 3MB Internal ROM

   Synth        Sample       PCM Card     Data RAM     Assignable         Built-In          Internal
   Model    Playback Rate     Slots      Card Slots     Outputs          DSP Effects        ROM Size
   -----    -------------    --------    ----------    ----------    -------------------    --------
U-20         44kHz           2            1             2         Reverb/Chorus/Delay      3MB
U-220        44kHz           2           None           4         Reverb/Chorus/Delay      3MB
U-110        32kHz           4           None           6         Tremolo/Chorus           2MB