I wish I had been taking pictures of this whole process. In case you haven’t been following along, I have a Yamaha DX7s which, since it’s “inception” in the late 80’s, has seen many owners and a lot of disregard. Two keys were broken, along with the pitch wheel being “wobbly” and the battery needing to be replaced (considering the amount of leaked acid on the battery, I’d guess for several years). Since I know the value of the DX7 (a really impressive partial list of users can be found here) I took it upon myself to “revive” this one.
For those not familiar, the DX7 is a digital Polyphonic (but monotimbral) FM Synthesizer made by Yamaha starting in 1983, and (arguably) the highest-selling synthesizer ever made. This success is for very good reason: it has a lot of performance options, was one of the first keyboards to feature MIDI, and uses FM (instead of the Subtractive Synthesis used by most Analogue Synthesizers) to generate a huge variety of sounds from very “pure” sine waves to quite complex pads, percussive sounds, and textures (not to mention really sweet bass). A bit after the original DX7 came out, Yamaha made a number of HUGE improvements (added stereo outputs, bi-timbrality, improved MIDI, and more) and released the DX7 II. The problem was that the DX7 II was too expensive for most musicians, so they released a “slightly scaled down” mono version more designed to be used on stage, and called it the DX7s. This is where my synth falls…
So I found a “how to change the battery on a DX7” tutorial, and ordered my replacement battery from Yamaha. It came less than a week later, and I opened up my synth. Since the “s” model is a different revision than the “Mk I” DX7, I found that MOST of the actual “disconnect this wire next” parts of the instructions didn’t match up. On the other hand, there is enough useful information in the above referenced guide to get you started if you are patient, intelligent, and careful (well, two out of three ain’t bad..). I started by flipping over the unit and taking the bottom panel off. After that it’s pretty obvious which board is the “motherboard” (it’s the one that’s about 8″ by 5″ in the middle toward the left side, with ALL the wires connecting to it).
To remove the motherboard, I *carefully* disconnected the cables from around the edges first. It’s pretty clear where all the wires would connect back up, but some people would go as far as to mark them with tape or something. I am not one of those people, so I just disconnected them. Next I removed ALL the screws on the back (there are 3 around the MIDI jacks on the back and 2 more over by the audio jack). Make sure you find a safe container to keep your screws in, organized by where you took them from if possible – there are like a zillion screws in this thing, and it’s easy to forget where you got them if you just throw them all together. After all that is done, the motherboard is still attached by two “different” screws, accessible through holes in the motherboard itself toward its left side. Once that was done, I carefully lifted the board off and set it on a static bag while I worked on it.
The battery is pretty obvious here, but note that this battery is special and you can’t just buy one at Target or something. It has two little permanently attached legs, but it otherwise a normal CR2032 disc battery. Some people remove the whole thing and attach a battery holder and then put in a normal CR2032. Some people (somehow) leave the legs attached and pry out the battery itself, and then replace it with a normal CR2032. I ordered a new actual DX7 battery from Yamaha. To each his own, I guess.
Removing the old battery and soldering in the new one was really not that hard. Granted, if you haven’t done any fine soldering before, and/or don’t have all the necessary equipment to safely/properly do that, you should really let someone else do it, but it’s not that hard. After that fun, I put the keyboard back together and turned it on, and everything was A-OK…
…except that I had totally forgotten to fix the two broken keys (including ordering them from Yamaha!).
So I ordered the two new keys, and waited. Meanwhile, I took the synth back apart. To get to the actual keyboard assembly, you “simply” remove everything above it (with the synth flipped over, of course). This means the Motherboard, the Power Supply board, and the Key-contact assembly. Like I said, about a zillion screws. I wasn’t careful when I removed my keyboard assembly (I was lazy and didn’t remove all the cables) and broke the thin ground wire where it attached to the assembly itself on little solder tabs on the end. So this is a warning: REMOVE ALL THE WIRES FROM THE KEYBOARD ASSEMBLY. This will help you avoid a lot of unnecessary wear-and-tear on the “guts” of your keyboard. Thankfully, with more careful soldering, I was able to fix the ground wire (I think..).
While I was waiting for the keys to come, I took off ALL the other keys and cleaned out 20 years worth of grime from on, in, and around, the keyboard assembly. It was pretty nasty in there, but the exercise not only gave me something to do while I waited anxiously for the keys to arrive, but did help improve the action of the keyboard quite a bit. Finally yesterday the keys arrived, and I attached them (I really wish I had pictures here..the keys have a metal spring-bar thing under them that sort of pushes on a little slit in the casing underneath the assembly. You have to sort of line up the spring first and then push the key forward and down and it snaps in. If you have one in front of you you’ll see what I mean).
Once that was done, I took off the pitch wheel assembly, and found that the wheel simply needed to be “snapped” back on. I did that and adjusted the nut on it for the right tension feeling when moving the wheel, and then put it back on. Then I put the keyboard all back together and turned it on in my studio.
The keys felt really nice and springy again (and ALL of them worked right), but when the synth turned on it showed the normal
>> Yamaha DX7s <<
screen, followed by
Change battery!
I was rather confused/frustrated by this, but at that point, I had to go to bed.. maybe tonight I’ll pick up where I left off on that one and figure out what’s going on…
The saga continues in Part 2.
Tags: Changing battery in DX7s, DX7s, DX7s Test Mode, Repairing DX7s, Yamaha DX7
hola matthew, thanks for your website. I have a dx7s that I love to play. The battery needs changing and I have the battery yet have been unable so far to replace it, due to not knowing how to open up the top panel. I opened the bottom panel but the motherboard screws on the back edge are inaccessable. Any comments and/or suggestions would be very welcome. I am a woodturner by trade and a guitar player/keyboarder for life, with some basic electronics wiring and soldering skills. Thank you for your time and knowledge.
herb, you dont even need to touch the screws you’re talking about, they’re attached to something on the motherboard itself. The “only” screws you have to pull out is the 14 screws on the bottom, and then the 4 screws on the backside of the keyboard which you can see are attached to the motherborad once you have opened it, and the 3 screws attached to the motherboard to the middle of the keyboard, which you can easily access, and then there are the last 2 screws which you can access through the designated holes.. that’s it, and then of course the stuff about changing the battery.. I did just use a normal C2032 battery and a plastic “peg” I made myself and some high-quality insulation tape, that the worked for me. I just let the pins be as they were and fastened the new battery with the peg, and the peg did I fasten with tape.
A little unauthorized may som people say, but what the fuck? my keyboard plays and it sounds as it should, so no reason to make it more complicated than it is… theres just a hell of a lot screws…
Hello, Matthew
Glad to find your site. Can you suggest how to replace a few keys, how to retension the spring-stip? I would be so grateful/ I have an old brown Dx7, not highly skilled but would like to give it a try, I have removed the keyboard after carefully detaching the wiring including the ground. Thanks for any guidance you may be able to provide. Joseph
Joseph:
I’m not sure where people got the name Matthew (it’s Jason). Anyway, to get the keys off, It’s been a while now since i did this, but try this: with the keybed “exposed” and sitting rightside-up in front of you, take one hand and push down on the top of the key, on the end of the key farthest from you. Then take the other hand and apply GENTLE pressure pulling the key toward you. The key should slide out of the “slot” it’s in and then “spring up” a little and be out. It’s one of those things that is hard to explain but easy to show someone.. I wish i had taken pictures/videos of changing the keys on mine, as a lot of people seem to have a hard time with this. It took me a WHILE to get it, too. Anyway, once the key is out, take a look at the metal spring strip itself and make sure it’s not broken or something. These are “spring steel” and really can’t/don’t need to be ‘retensioned’ so much as they can come out of the little notch on the key itself. Just taking the key off, cleaning the area under/around it (!), and putting the key in again carefully so the strip stays in the “notch” will likely make a world of difference on the springiness of the keys. And if you have to order a new key from Yamaha, you’ll have AMPLE time to get it good and clean
I hope it helps.
Hi can you give me details of how you got in touch with yamaha to order the battery. I can not get any details of where to get a genuine yamaha cr2032
many thanks
gerald
gerald
I linked to this page in the post, but the specifically useful part is easy to miss, so I’ll paste it here. In short, I called them at this number:
———-
Order parts by phone: (714) 522-9000, Please call Monday – Friday, between between 7:30am – 5:00pm PST/PDT and press option 1. Sorry, USA customer ONLY. Please verify your part when you order to prevent a re-stocking charge.
———-
For your sake I hope you’re in the US (or know someone in the US who will order it for you and ship it to you). Aside from that, the Yamaha rep I spoke to was quite helpful and polite and seemed to know exactly which keyboard I was talking about (but having your model #/serial # handy wouldn’t hurt). Good game Yamaha for supporting a 20 year old synth.
I hope it helps.
hi jason. i,m in the uk and have had my dx7s for 10years(love it) but after a bit of non-use over the last 5-6 months(due to work), on trying to get sound -nothing at all ????
it starts up ok,synchs ok with pc via midi and plays sounds from my music software library BUT wont let me play its individual voice-cart sounds on the dx7??? any help-directions on what to do greatly apprecited my friend.
with thanks stumpi
Stumpi: Wow sorry for the delayed response on this (3 months delayed!). I hope you have gotten your DX working in the meantime. When you say it plays sounds from “your music software library”, do you mean, as a MIDI controller? Otherwise if you press Int/Crt does it play sounds from Int but not Crt, or does it make no sounds now matter what? One thing you may want to check if MIDI works but NO sounds come out is if Local is off. To access that, press Edit and then press button 63 repeatedly until “Local” shows on the screen, then press the “Yes/On” button. If MIDI Local is ON and it still doesn’t make any sound, the only other suggestion I have that doesn’t involve taking your DX apart and checking ribbon cables is to press the “Performance” button and select a different Perf. Maybe the output is turned down/off in that Perf? I hope this helps.
Hi Jason, I have a DX7D II and it hasnt been starting up lately. its shows nothing on the screen (just squares across) and I dont hear any sounds. Do you think the internal battery is dead and needs replacing?
Jas: I hope you have also gotten your DX working in my long absence. If not, as far as I know, squares on the display indicates that it isn’t properly able to read whatever the microcontroller is sending. These things are really touchy, so it could be just a bad battery connection or it could be that one of the little ribbon cables is not seated properly. Honestly if you’ve had the DX for a long time and not changed the battery, I’d try that since you’ll likely have to before long anyway. Please note that the DX7D II is a bit different on the inside than the DX7s I documented here. If anyone wants to send me a DX7D II I’d be more than happy to learn and document it
Hey -
My DX7s is doing the same thing. I spoke with Yamaha and they said it’s a hardware problem, because the battery was changed recently. Also, they said to press EDIT/16/32 to put it in test mode, but that didn’t work.
GSH
Hi,I am trying to open my DX7s and change the battery. I unscrew all the screws and couldn’t open the top panel. The only thing I can do is to take out the bottom lid,which is not the correct way I think, it needs to open the top panel.
How can I do this please?
Thanks
Alexis: This had me confused as well. Actually this is where the DX7s is different than some of the other DX models. On the “s” you do need to take off the bottom panel. The top panel is “all one piece” more or less. In order to get at the battery you need to take off the bottom panel. My Part 1 describes this process. I hope it helps.
Hi Jason,
I found your ‘Reviving the Yamaha DX7s’ article really useful when I started work on my own recently. I replaced my battery with a battery holder, installed in a more accessible location. I documented the whole process, with descriptions and images, in case it might be of help to anyone else. You can see it at How to replace the battery in a Yamaha DX7s.
Cheers,
Alex (aka ukebloke)
Oops, that last link didn’t work. The URL is:
http://www.alexannesty.com/dx7s-battery-replacement.php
Thanks for your site:
I found it after I changed the battery in my DX7S. Mine is the same unit as descibed on this site. I needed to use it this week and didn’t think I could wait for a battery from Yamaha. I tried to find a Sony or Panasonic but settled on the brand that Radio Shack sells.I removed the original Sanyo CR2032 with the drab orange shink wrap around the edge. Here is where I would like to issue a “WARNING”!!! If you choose to remove the solder tabs from the old battery and solder them to the new one “DO NOT APPLY TO MUCH HEAT TO THE NEW BATTERY BECAUSE IT MIGHT EXPLODE”!!!! MY FIRST ONE DID. I was successful on my second one although I used an energizer battery I had in the cabinet. My DX works fine. “I STRONGLY SUGGEST!!! IF YOU CAN WAIT ON IT, ORDER IT. From what I’ve seen they are not expensive and you will probably save yourself a lot of time, grief, trouble and maybe YOUR SIGHT! TB
Yamaha DX-1 synthesizer only 140 made…
Among Yamaha’s DX line of synthesizers, the Yamah DX-1 is definitely the biggest and most expensive synthesizer out there. Only 140 were made by Yamaha back in 1984 to 1985 but it is rumored that there are maybe 210 made. Expect to find these syn…
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I appreciate the discussion on this site.my DX7iiFD doesn’t display digits on the screen &the button are not responding.how can i repair them.pls send reply to my email: mcjoker4u@yahoo.com
was this ever fixed? sounds like my problem also, see post below. Thanks thanks MT
Hello. Not NET savey, not computer savey but I am attempting to put a battery into my old DX7. Last week I ordered a battery from Sam Ash. Since I am beer challenged, me thinks, let the tech install the battery. Hmmmmmm 05/23/10
P.S. 20 plus years out of music. What make and model of amplifier would be good to buy to plug the Yamaha DX7 into? A. MIDI ?
B. Tube ?
C. Solid state?
D. Tesla coil? O \
0 /
Yes , one keyboard. I will attempt to USB audio interface with m-audio Fast Track. Thanks for direction Plan A.
I would be remiss here if I didn’t also recommend a piece of software to record on your computer with. I highly recommend not even bothering to install the feature-limited demo software that comes with the FastTrack, and to check out Reaper instead. It is free-and-uncrippled-until-you-you-decide-to-pay-for-it, and then $60 for a noncommercial license when you do. It supports MIDI sequencing and audio recording (on the same track even!), has really easy and useful built-in effects (especially check out the ReaEQ plugin!) and does a LOT more stuff than I can even adequately describe. Just check out their page for more info.. I’ll say I record my DX7s in Reaper and it works great.
The Reaper website is nice. Thanks for direction. Will pay for it and download. (Some women I’ve known like to be payed.) %>
I had recently purchased a 2nd (3rd?)-hand DX7 Mk1 with e! card. Previous seller stated unit was bricked; upon powering up the Numeral LED’s shuffled about and the top row of the lcd char screen showed solid blocks. He said the battery was changed by previous owner. I took it in as a project/parts unit. physically flawless…I tested the battery, 2.7v, well within normal operating spec. I disassembled and checked the solder points for the replaced battery, which seemed good. I removed some flux rosin about the battery’s points. Tested for voltage across several traces, which reported good news. I might try the external battery AAA pack. I don’t know if the thing crashed hard when the e! card was installed, before or after the battery change etc etc; seller wont contact me, he got his c-note. Suggestions? Thanks thanks MT
I know this may sound like a dumb question but how to I get the battery voltage displayed on my newly aquired DX7S? I can find plenty of mention of the ‘battery check’ on a DX7 but the keys used on the DX7 do not ’seem’ to appear on the DX7S!