Information on these keyboards is so scarce, so I really appreciate your willingness to share this. I had given up on this keyboard and thought that it would become a mere conversation piece in my living room. I cannot thank you enough for taking the time to write this information up. I don’t know what that portion of the board looked like out of the factory because I don’t have another DX7 to compare it to, but I can only assume that the battery was changed before in an attempt to repair the unit and someone made a mistake. I have no idea how my motherboard ended up that way. Figuring I had nothing left to lose, I put a small bit of solder over the top to bridge the two, and VOILA – when I turned on the DX7 the battery reading was at a sensible 3.0v and my memory stays in tact now! The two separated vertical/parallel solder spots looked clean and square with no evidence of tampering, so I had been assuming that it came that way from the factory, but when I really looked close I noticed, “Hey, this positive terminal isn’t connecting to ANYTHING right now on either side of the board!” It was being separated by that otherwise professional-looking gap. What I found was that the trace coming off of the positive terminal of the battery that was supposed to connect to the next component had a gap in it in this kind of shape: -||. I was ready to give up and assume it was a deeper motherboard issue until I read this again and decided I would take a look at the underside of my DX7’s motherboard and compare it to yours. The internal memory would be OK for about 30 minutes and then slowly start to corrupt until everything was lost.

No matter how many times I tried to redo the battery I was getting a strange battery reading of 4.5V in the Function>Battery Test screen for what is in fact a 3V battery.

I have read just about every page on the internet in English and Japanese, including this one, time and time again. I have been trying to replace the battery in my second-hand DX7 mk1 for the past 3 days. You can click on the images below to get a larger image: Yamaha DX7 open with keyboard in place Yamaha DX7 close-up of connector C6 Yamaha DX7 open with keyboard removed Yamaha DX7 main board Yamaha DX7 solder side of main board near battery Overall, replacing the battery was not a difficult task but somewhat time consuming. I had to solder in a short jumper over the trace to fix it. The trace between the battery’s positive lead and the next component (which is a diode) had been severed. There was a service sticker from some repair shop on the back of the unit. The battery evidently had been replaced before. To remove the old battery, I used a solder sucker to get rid of most of the old solder which makes it easier for the old battery to pry up and out.Ĥ. You have to angle the main board between these tabs and the back of the chassis to lift the board out. There are two tabs that are used to mount keyboard. The main board was a little difficult to remove from the chassis after all screws and connectors were out. The connector labeled C6 on the main board is not connected to anything.Ģ. There were a couple of things I noticed while disassembling the synth.ġ.

I found some very helpful instructions through Dave Benson’s DX7 Page ( also archived here) for replacing the battery. To replace the battery you basically have to take the whole synth apart, but Yamaha tries to make the procedure as painless as possible.

I found a suitable battery through Mouser (part number 614-CR2032FH-MFR). I first thought that I could just run down to Walgreens and pick up a “button” style battery and pop it in but after poking around on the Web, I found out that the DX7 uses a special kind of CR2032 battery with solder leads mounted on it. The manual for the DX7 states that the battery should last for 3 to 5 years and it was well past that time. I recently had the chance to replace the battery in a Yamaha DX7 Synthesizer.

Dx7 battery pulse