Roland D-70
Restoring the Roland D-70 and firmware upgrade

I bought this synthesiser somewhere between 2009 and 2012. I am not sure exactly when I bought it, (although I think it was 2010,) but I do remember that, as is my standard practice after I acquire an instrument I will normally change the battery.

I purchased it because I wanted a 76 note keyboard, I didn't at the time have a Roland D-50 and wanted a D-series synthesiser and I wanted a controller for the MIDI setup I had at the time.

Anyhow some where between my many moves over the last 10 years, both studio and home, it has been damaged. 

This series of videos will fix these issues and restore the Roland D-70 back to full operational health.

Roland D-70 – Assessment – Restoration Part 1

In this first video of my Roland D-70 restoration series, I walk through the three main tasks I've identified for this project. The Roland D-70 is in reasonably good shape overall, but there are some specific things I want to address before it goes back into regular service in my studio.

The first job is to replace the battery. I've owned this Roland D-70 for well over a decade, and with the synth having spent much of the last five years in storage, I have no record of when the battery was last changed — so a fresh one is long overdue. After that, I'll need to restore the factory sounds, either via cartridge or SYSEX.

The second task is fixing a key that isn't returning properly after being moved in and out of storage. I suspect it's a spring issue, and I already have spare springs on hand. The third cosmetic job is sanding and polishing a key that has been gouged by a plug — something I feel strongly about preventing in the first place.

Finally, and most excitingly, I'll be upgrading the Roland D-70's firmware from version 1.10 all the way to 1.19, the final release. This isn't a simple flash process — it requires physically swapping ROM chips on the motherboard, which I'll be covering in a dedicated video later in the series.

Roland D-70 – How to Access the Synthesiser – Restoration Part 2

In this video I show how to safely open up the Roland D-70 to access the internals. Before doing anything else, I flip the whole unit upside down, which is how you gain access to the chassis. It's important to prop the Roland D-70 up on foam strips to protect the joystick from making contact with the bench.

Once it's safely propped, I work through removing the screws — around 23 in total across the base, with the back-edge screws being a different size that need to be kept separate. With those out, the bottom panel lifts forward and up over an internal metal lip and comes cleanly away.

Inside, I can see the general layout: the transformer, main circuit board, card reader, and I/O jacks. I also notice that the aftertouch board ribbon runs along the length of the keyboard, and some of the key weights are showing a little surface rust — nothing serious, but worth noting.

With the Roland D-70 now open, I'm ready to begin the actual restoration work, starting with the faulty key that's been irritating me every time I play in the upper register of the keyboard.

Roland D-70 – Removal of the Key Bed – Restoration Part 3

Getting the key bed out of the Roland D-70 is, frankly, one of the trickier parts of this restoration. The boards are all attached to the key frame, which means you can't simply slide the key bed straight out — there are screws underneath the boards that need to be accessed first.

My approach is to undo the boards and pivot them forward rather than remove them entirely, giving me access to the screws beneath. I make sure to label my bits boxes carefully so that every screw goes back into the correct hole — something I always do when a job involves this many fixings of different lengths and types.

Once the boards are pivoted, I disconnect the two ribbon cables connecting the keyboard to the main circuit board, taking care to lever the connectors gently so the ribbons aren't damaged. I also disconnect the aftertouch board ribbon, which requires a slow and steady pull to release cleanly.

With everything disconnected from the Roland D-70's chassis, the key bed can finally be lifted free. It's a fiddly process, but with patience and a few photographs taken along the way, the keyboard and frame are cleanly separated and ready for the repair work to begin.

Roland D-70 – Fixing the Broken F Key – Restoration Part 4

With the key bed out of the Roland D-70, I can get to the root of the problem with the key that's been feeling limp and unresponsive. After closer inspection off camera, it's clear the spring is the culprit — likely overextended beyond its tolerable limit through all the moving and storage over the years.

The Roland D-70 uses a sectional locking strip design rather than a single strip across the whole keyboard, which makes this repair more manageable. I use a palette knife to carefully lift the relevant section of locking strip, which reveals a nicely designed system of raised contact points against the keys.

Once the strip is off, pulling the key forward and upward releases it cleanly from the key bed. I compare the old spring with a new spare — the wings appear to sit slightly further apart on the new one, but otherwise they look near-identical. I fit the new spring by seating it into its slot and routing it through the two retaining holes, then press the key back into place.

The result is immediately satisfying — the key now returns crisp and consistent, just like the rest of the Roland D-70's keyboard. The locking strip goes back on with a little pressure from a flathead screwdriver, and that repair is done. Easier than I expected, if I'm honest.

Roland D-70 – Fixing the Rough and Damaged E0 Key – Restoration Part 5

In this video I tackle the cosmetic repair on the Roland D-70's lowest E key, which has been gouged and roughened by a plug resting on it — one of my biggest pet hates. The damage isn't severe enough to warrant replacing the key entirely, but it needs attention before I can consider this restoration complete.

I start by wedging the key down with a decorator's scraper to keep it stable, then work over the raised ridges with wet and dry sandpaper and warm soapy water. The soapy water is important — it carries away the plastic dust as you work and stops the paper clogging up. You can actually see the plastic being worn back to smooth as you go.

Once the ridges are knocked back, I move on to T-Cut cutting compound, working it in with a circular motion for around 15 minutes to remove the fine abrasions left by the sandpaper. The surface comes up noticeably smoother, with just a faint residual indent that won't affect playability at all.

The final step is Maguire's plastic polish across the entire Roland D-70 keyboard, which leaves every key with a beautiful smooth feel and a subtle shine. There's something genuinely satisfying about the way the keys feel after a proper polish — and with the broken key already repaired, the key bed is now ready to go back into the chassis.

Roland D-70 – Reinstalling the Key Bed Back in the Chassis – Restoration Part 6

With all the key bed work complete, this video covers putting the Roland D-70 back together. Off camera I've already slid the key bed back into the chassis frame, so I start by reattaching the frame with its three screws, being careful to get the long screw seated correctly first. I also note a mystery spare screw that was floating around inside the case — I can't find where it's come from, so I log it and move on.

Reattaching the aftertouch board ribbon is probably the most delicate part of this stage. The ribbon needs to be perfectly aligned before any pressure is applied, because forcing it at the wrong angle risks tearing it — and replacing the aftertouch strip is not something I want to deal with. With patience it goes in cleanly.

Next I refit the boards, starting with the I/O panel and working through to the main board, making sure all the cables are routed correctly before finger-tightening the screws. I also reconnect the two ribbon cables to the Roland D-70's main circuit board, seating each one carefully and making sure the ribbon lies flat under the retaining tape.

A useful tip I share here: if a screw won't locate, try turning it the wrong way first — as if you're unscrewing — until you feel it drop into the thread, then drive it in normally. With everything back together and snug, the Roland D-70's keyboard restoration is done, and I'm ready to move on to the circuit board repair.

Roland D-70 – Repairing the Damaged Circuit Board – Restoration Part 7

This was an unplanned repair, while working on the Roland D-70's key bed, I found a small fragment of circuit board that had broken away from the main board. On closer inspection, it turns out to be part of an earthing trace around the edge of the board, so it has no effect on the Roland D-70's operation whatsoever. Even so, I want it properly secured before I close everything back up.

My approach is to use superglue, since the fragment carries no electrical function. Before applying any adhesive, I clean both mating surfaces with IPA (isopropyl alcohol) to remove any contaminants that might compromise the bond. (One side note: IPA dries your fingers out badly, so I always borrow my partner's hand cream afterwards to put the moisture back in.)

With the surfaces clean, I apply a small amount of Loctite superglue and use pliers to hold the fragment in position, keeping my fingers well clear. The initial bond forms in around 30 seconds, but I leave it for a full 20 minutes to cure properly before handling it again, regardless of what the packaging claims.

Once cured and the final screw is back in place, the circuit board work on the Roland D-70 is complete. Before moving on to the battery and ROM upgrades, I plan to power the synth up off camera and confirm that the keyboard is producing sound correctly across all keys.  Then we're on to the final stages of the restoration.

Roland D-70 – Upgrading the Firmware and New Battery – Restoration Part 8

This is the big one, upgrading the Roland D-70's firmware from version 1.10 to the final release, version 1.19. Fortunately, when I open the machine up I found the ROM chips are already socketed, which saves me the job of fitting sockets myself. The new chips have been sitting in my workshop for about two years waiting for this moment.

Before touching the chips, I remove the old battery, a Sony cell that tests as borderline on my meter, so the timing on changing it is actually quite good. Pulling the battery also removes the 3-volt supply from the board, which is important when swapping chips, since live voltage on the board risks damaging the new ROMs.

Chip orientation is critical. I note carefully that on both the A chip (IC4) and the B chip (IC9), the notch faces toward the wall and the new chips must go in the same way. I use a chip extraction tool to pull the old ROMs cleanly, then gently coerce the new chips' legs into alignment with an insulated screwdriver before seating them fully with a dedicated seating tool to ensure even pressure across all pins.

With the new firmware chips in place and a fresh battery installed in the Roland D-70, the hardware work is done. I store the old ROMs safely and prepare to close everything up.  Next comes the initialisation and factory sound restore, which will be the final video in this series.

Roland D-70 – Unlock the Upgrade by Resetting the D-70 – Restoration Part 9

This is the home stretch, the final video in my Roland D-70 restoration series. With new ROM chips fitted and the battery replaced, the synthesiser needs to be reinitialised before it will function correctly. Powering on shows a "no RAM card" message, which is exactly what I'd expect and confirms the Roland D-70 is alive and waiting to be set up.

The first check is to verify the firmware version. Holding the number 1 key while powering on takes the Roland D-70 into diagnostic mode, where I can confirm it is now running firmware version 1.19, dated 9th March 1993 — the last ROM Roland released for this synthesiser. A very satisfying moment.

Next I perform a full memory wipe by holding the number 8 key on power-up, then configure the Roland D-70 to receive SYSEX: exclusive receive is set to on, device ID set to 17, and the hardware memory protect switch on the rear panel moved to the centre position to disable write protection. I use MidiOX on PC with a 32-byte output buffer and a 60-millisecond delay after each F7 command to accommodate the Roland D-70's relatively slow data rate, and the factory SYSEX file transfers in around two minutes.

A power cycle later, all the factory patches are restored and the Roland D-70 is back in full voice. I also demonstrate the same process using SYSEX Librarian on Mac, with transmit speed set to 10% and a 60-millisecond pause between messages. 

Battery renewed, firmware updated, all keys working this Roland D-70 is ready for another seven or more years of service in my studio.