The best description of this is when you turn on the synth, you will see the display screen light up with all characters on the top line light up, but the bottom line of the display will be dark. They keyboard is completely unresponsive with only the power switch working.

I found that if I left the keyboard on for a while, it would finish booting up and would play normally, but then after turning it off and back on again it would do the same thing. I was able to get the keyboard fully functional again by doing a full reset. You will need to open it up, take out the backup battery and let it sit for a little while, maybe an hour or two. Put the battery back in after that and initialize it when you start it up again. Make sure that you are comfortable both opening the keyboard and locating the battery as well as backing up your data and know how to initialize they synthesizer. I have posts describing all of this, just search for D-20.

I’ve been lucky since doing this, the keyboard has been behaving itself. It really is no fun constantly opening and closing the keyboard body, so if you do have an easier way to deal with this freeze definitely let me know.

I was recently looking around online and found a great resource, a freeware SysEx Librarian program for Macintosh OS X (http://www.snoize.com/SysExLibrarian/). I use an old Macintosh Powerbook running OS X 10.4 and an Edirol UM-2ex MIDI/USB interface for swapping out kit sets on my Roland TDW-10 setup with VDrumLib. So I had visions of being able to do the same thing with my D-20 patches and tones, which seemed pretty convenient.

I went through the whole SysEx load on the keyboard after turning memory protect off, and after it finished, the keyboard was locked up. I turned it off and tried turning it back on. It started up, and then the display screen went dark. Not blank, but dark. I attempted a reset/initialize by holding down the TUNE/FUNCTION and WRITE buttons on startup, but after the initial startup screen on the keyboard it displayed something troubling:

MAIN BOARD ERROR

My first piece of advice: don’t panic. You can try another restart, but it will probably yield the same dark display screen. What’s going on?

The problem is that if you have a D-20 model with a ROM version of 1.03 or less, when attempting a SysEx dump you will have this lock-up and will have to jump through a few hoops to fix it, which I will outline below.

You will have to open up your D-20 and remove the backup battery. You will find instructions and some warnings on this in my article on removing the backup battery. What’s happening is that the keyboard is experiencing an error that locks it up, but it is such a serious error that the backup battery actually preserves the bad data in the keyboard memory which perpetuates the error. Removing the backup battery clears this and breaks the error loop. Leave the keyboard without the battery for 5 minutes or so to make sure it does clear the memory. Please also be sure that you have the keyboard unplugged before taking the bottom off.

After you replace the backup battery and replace the bottom cover, plug it in and hold down the TUNE/FUNCTION and WRITE buttons when you turn it on. The keyboard will initialize to its initial "New Out of the Box" state and you will be able to perform a restore of your settings, tones, timbres and patches, which you will need to do since the memory has been wiped by removing all power for the backup for the keyboard.

To safely transfer MIDI dump info to the D-20 with an earlier ROM chip, you will need to use the "ONE-WAY BULK RECEIVE ALL DATA TRANSFER" mode on the keyboard. Check the manual on this one…it’s not difficult, but it is an extra couple steps compared to modern plug & play.

So there is still hope. Incidentally, here are all the combinations of startup modes that you can initiate by holding down function buttons as you turn the synth on:

• TUNE/FUNCTION + WRITE: initialize the D-20
• EXIT + EDIT: memory test
• EXIT + TUNE/FUNCTION: controller test - shows bender value, etc.
• EXIT + MIDI: keyboard test - shows key and velocity
• EXIT + COMPARE: D/A adjust and PCM test; band buttons play PCM sounds for D/A setup
• EXIT + ENTER: lamp test - all the lights blink
• EXIT + PERFORMANCE/MULTI-TIMBRAL: floppy disk test

Roland has a backup battery in a lot of their systems that saves your sounds and your changes to those sounds in the synth’s memory when the unit is off. They suggest that you have the battery changed every 5 years or so, and here I am 20 years later. I have to say, I was getting Check Battery messages, but it was still working and saving data.

So after looking for a LONG time online for model-specific info, instructions or moral support for changing a Roland D-20 battery, I found a few pieces of good advice, with most everyone else ignoring the D-20 and talking about the D-50 or D-110 instead. So to contribute to future D-20 battery changes, here is my own description of the process.

In my past I have been heavily involved in computer technology. It is very important that you be somewhat comfortable opening up your keyboard and poking around inside if you’re going to change your battery. If not, I strongly recommend you find someone to do this for you instead.

You will need to get yourself a 3-volt 2032 Lithium battery to put in your keyboard. You can probably find these at your local drug store or online. You should also have a backup card to save all sounds and rhythms, as once the battery is removed you very well might lose all your sounds. The original cards for the D-20 are no longer available, but you can use a Roland 512-G card to save everything, it works just like the old memory cards. I got mine from Voice Crystal at http://www.voicecrystal.com/roland.htm. You should also have a demagnetized phillips screwdriver, which you can usually find at your local computer or hardware store. It actually might not matter, but I tend to play it safe with electronics.

First: make sure you back everything up on your card. When you’re done, turn off the keyboard and unplug it.

Turn the keyboard over and place it on the floor so the back of the keyboard is facing you (the keyboard label and all the ports are facing you), and get a book or two to prop it up so the pitch bender lever doesn’t get broken on the floor. Remove all the screws from the bottom of the keyboard, apart from the ones which hold the rubber feet. Now remove all the lower screws on the back of the keyboard, i.e. those farthest from the floor. I think it’s about 6 or so. These hold the back of the bottom plate on the keyboard.

Carefully lift the bottom off the keyboard and set it aside. First thing to notice is the power supply on your lower right. DO NOT TOUCH IT. Fortunately, the battery is on the opposite side of the unit, so you shouldn’t need to even be near it. These things hang onto power for a long time, and you can receive a very serious shock if you touch it, so please just stay away from it.

You should see the battery in its holder on the lower left. It is just held in there with a little retaining clip. Mine had a little black plastic knob on the clip which I just propped up and carefully slid the battery out. Now it is just a matter of lifting up the clip and sliding the new battery in. Make sure it’s fully seated in the receptacle.

While you’re at it inside the unit, it’s a good time to clean out any excess dust.

The hard part is over. Now you just place the bottom cover back on the keyboard and make sure all the screw holes line up. Start by putting the screws back on the back plate. After that, you can put in the screws on the bottom of the unit. With all the screws, you should be only hand-tightening; don’t over-tighten them. They should be snug and not able to come back out.

You’re all set! Plug it back in and reload any data from your backup card that might have been lost with the battery change. I actually didn’t lose anything on my change, but it is better to be safe than sorry, especially if you have a lot of custom sounds. Hope this helps anyone out there searching for how to do this.