Yamaha DX-7 Repair (No Sound, Replace Battery, And Fix Keys)
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- เผยแพร่เมื่อ 12 ก.พ. 2023
- A while back, I rescued a Yamaha DX-7 from someone's basement and brought it back to life.
It would power on, but wouldn't make a noise, or little if any. The keys also needed to be reset. While inside, I decided to also replace the battery to prevent what would probably be the next thing to fail in this synth.
The synthesizer needed its presets reinstalled since the battery was removed. I didn't show that process in this video, but it's pretty easy with either the cartridge or via MIDI. I could make another video to explain that if it's requested.
Music for this video was made using Arturia's DX7 plugin, so it could have been done with the DX-7, but I decided not to to save on time (sorry) - เพลง
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I can’t believe we didn’t get to hear you play it at the end!
thank you for the video. I have the correct voltage on c5 and c6 connector on thd DC Board. So i dont think that the capacitor are damaged.
I have no sound. The only thing i hear when i power on the dx7 is a very quiet sound like a Policecar Horn.
Hav you any idea? Thanks for your Help
Even though you are getting the right voltage doesn't necessarily mean the capacitors are still good. They can still hold the correct charge, but may not be able to properly charge/discharge at their intended rate.
In my experience, if there is little or no sound and there is a background noise; It’s usually a sign it needs new caps. If you have some experience soldering, it’s not hard to swap them out. I was able to get all the caps I needed from my local electronics store for not much. The greatest expense is the time it takes to get the old ones out and put the new ones in.
Does everything else seem to work out fine?
One thing I noticed in my research of my dx7, is that it is really important to replace the rectangular gold rifa capacitor in the top right corner. They are known to spontaneously catch fire when when the power switch is off. Until I redo mine, I keep mine unplugged. I also wanted to ask you what cleaner you use to clean the flux off the board? Thanks for sharing!
I'm also thinking its a good idea to add an earth ground and a 3 prong power plug. Thats on my to do list as well.
Yeah, I've read about the trouble those capacitors could cause. I didn't replace mine (even though I should have) because all off my gear stays unplugged if it isn't plugged into a power conditioner that would need to be turned on first.
As for cleaners, I'm using Gunk electronic cleaner - contact cleaner and a high percentage (+90%) isopropyl alcohol.
Adding a ground to the power cord would a nice mod. You might have to drill the chassis a bit to make room for it though. I would like to hear how that turns out
thnx for great video. I found the same issue with my DX7 with the tabs like you in 14:20. Weren´t you trying to find the spare ones and change it? Those are pretty fragile to bend them back in proper position and as you have mentioned, they are really important as they are responsible for the sound as well as the velocity sensitivity... thnx for answering.
Your welcome and thanks for watching
I thought I was going to have to replace that peice, but after a lot of careful work I was able to get them straightened out. I skipped a majority of that work in the video because I may have been at it for about an hour or so till I got them right.
I sure you could find an extra one (or peices) out there on ebay or syntaur if yours is that rough of shape or if you think that buying a replacement is a wiser investment than your time
Curious what kind of grease to use when replacing the keys. Was thinking dialectic grease but wondering if it would affect the plastic in the keys.
What I ened up using was some 3 in 1 electric motor oil applied with a cotton swab. I'm sure a grease of some sort would have been better. Possibly something silicone based
If I were able to find cartridges do you think it may work? I don’t have electronic skills so do you think there are service people that would still work on these? Thanks.
If you get the for a good price is OK with box but trust me I had buy the in 3 different occasions and after few months no more sound.
Thanks a lot for this video! This helped restore a dx7 i picked up a few weeks ago. Mine has a similar issue with the sound, only it’s just rather quiet at full volume. I’m not much of handyman but I borrowed my friends soldering iron and I replaced the big capacitors on the DC. The output is a little better, but it’s still pretty quiet. Could you think of anything else I should do?
I’m thinking i should have replaced the small capacitors too, but do they really make that much of a difference?
If you can give some tips, that’d be great :)
Yeah I'm think you should replace the little ones too. Usually if I'm going to replace a capactor on the DC board, I just do them all. It has done the trick the 2 times I encountered this kind of problem (on this DX-7 and a CS-15).
The way I look at it is, capacitors are cheap and replacing a few more don't take that much time. Also they are part of a board that sends power to the synth and I would hate see other components down the line get messed up because of an power issue.
@@deltamumusic Will do, Thanks!
How do you decide what to clean with contact cleaner and what to clean with isopropyl alcohol? Is there a rule of thumb?
I'm sure all contact cleaners aren't alike, but generally I would keep contact cleaner away from plastics unless stated that it we're safe for them. I usually reserve contact cleaner for things like potentiometers and sliders because with the straw and force of compressed air, it can be easily be directed and blast out whatever junk is in there. Alcohol is good for when I want to moisten something like a cotton swab or cloth for cleaning larger areas.
Thanks for the video! What did you use to clean the exterior of the dx7?
I use rubbing alcohol as my cleaning solution. A rag is good for the larger areas while I use a combination or cotton swabs and a toothbrush for the tighter spots. I also used the toothbrush a bit to clean the button tops because the rag wasn't getting everything because of the texture
I replaced the battery on my DX7 Mark 1 with a battery holder. However, I am still getting issues where sometimes it will boot up and complain about the battery needing to be changed. Sometimes it gets stuck at the "Yamaha DX7 synthesizer" bootup screen, and sometimes it will boot into the internal voices, but they're all garbage and producing garbage sound and none of the buttons work. The buttons work before I took the main board out and I've made sure I connected all the connectors back properly and securely. I've measured the voltage on the battery and it's 3.2 volts and I made sure the connection is correct on the main board. I am noticing that The RAM chips (pin 24) are getting a fluctuating voltage from the battery, sometimes as low as 1.4 volts but as high as 3 volts. This is what the board taken out and just the battery connected. I did look at the schematic and there is a tantalum capacitor that I could try to replace. I ordered new caps for the power supply as one of them seems to be bulging. But I'm wondering if I should try to shotgun recap the main board.
I would start with the electrolytic caps on the power supply and see where that gets you. It's best to get start there and then work you way inwards.
@@deltamumusic I recapped the power supply, still having the issue. I decided to now recap all the electrolytics on the mainboard. I'm almost done. I'm also going to try to replace the transistors that detect the battery voltage, that might be why I'm getting a change battery issue.
I dug one out of an attic where it sat for at least 25 years. It lost its preset voices but battery check says 4.5 volts. It has no cartridges. What should I do to make it usable? Thank you.
Hey Joe,
Though cartridges are the easiest way to reload the preset sounds, they can be expensive compared to what they offer. Fortunately there is another way. You can send SysEx information to the DX-7 via MIDI. Here is an article that goes over the process: (keyboardchronicles.com/2020/04/06/uploading-patches-to-your-dx7-on-a-mac-with-osx/). This article is specific to mac os, but the process is similar for windows. Also there is a link to a huge collection of DX-7 sounds in there which you will want to grab since it has the original presets as well as a bunch of other fun patches.
Since you haven’t stated any other issue other than the presets missing, I would maybe try loading some patches on it first and then power cycle it so see it retains the information. I am suspicious of the high battery voltage though. A good battery should read about 3V. The battery is responsible for maintaining power to the RAM that stores the patches. Since RAM is volatile memory, information is lost if it isn’t provided power. So I do have a hunch that there is a power issue caused by faulty capacitors which means it may need work similar to what mine needed. I have read that some DX-7s may give out bad voltage readings so you may have an essential dead battery or even a fine battery in there. I do doubt the latter though since the batteries aren’t expected to last 20+ years.
If it needs work, maybe look for an electronics or synth repair shop. The parts (capacitors and battery) are cheap but the labor will be the expensive bit. I feel like a good general electronics repair person should be able to handle the job and do so at a cheaper rate than a synth specialist if they aren’t intimidated by the fact it is a synthesizer.
oh and do keep in touch. I'm curious to how this works out for you
It should be no more than 3V, 4.5V means it’s doing something wrong
I recently got this piano from my grandpa, it turns on but doesnt make any sound, i hope this video works, my piano doesnt have a cartridge, idk if that would be a problem too, is it necesary to have a cartridge? If so, what is it for?
In my experience, if there is no sound it's usually a capacitor issue, but of course there could be other things that could cause that.
Not have any cartridges isn't a huge deal. Patches can be loaded via MIDI. In a previous comment, I left a link to an article that goes over how to do that.
Hello! My Yamaha DX7 IIFD has a problem with its processor, it doesn't work how it should. Is the only viable solution to change the processor? Or can I also use the keyboard as MIDI to my PC? Thanks.
Hey, thanks for commenting.
That isn't a problem that I have had personally so I can't say if a simple exchange would solve your problem.
As for using it as a controller, I'm not sure if a faulty processor would hinder it from being used as a controller, but I would probably look for something else to use as a controller. I know with the MK1s they only output velocity levels between 0-100 as opposed to the 0-127. I think they fixed this issue in the later models, but I would still suggest a newer controller. Firstly, you wouldn't have to worry about any other 30 year old parts going on you, less cables to run, and you will probably get some programmable knobs and/or faders
@@deltamumusic Alright, I'll keep that in mind. Thanks so much for replying me.
I purchased one for $30 from a thrift store last year. It was missing a power cable. I slapped one on and plugged it in and it worked but said it needed a battery. I soldered the battery in but I didn’t solder it on the bottom.. only the top. The battery replacement issue went away from the display screen but now there is no sound.. seems the presets are wiped? I did plug it into my laptop and the keyboard functioned just fine with midi function. Any idea what it could be? Could me not fully putting the battery in have something to do with it? Have a guy willing to work on it but if it’s a simple solution maybe I’ll try again. Should also add mine came with the Grey Matter board
What a deal!
So what happened is normal. The battery's job is to supply power to the memory that stores the presets. The memory is viatile meaning once it looses power the memory is wiped. So when you took out the battery, you cleared the memory.
You can get the original presets online along with a bunch of other cool ones and load them up via MIDI. I have replied to another comment on this video where I shared a link to an article that goes over the process
@@deltamumusic MAN I’m so happy I found and replied to your video and got an answer! Found the comment I’m gonna try this as soon as I get home from work! Thanks a ton 🙏🏼
Update: I downloaded the Sysex software and that did solve my wiped settings problem but now there’s a new predicament! I’m not getting that cheesy piano tone or those crunchy brass hits… everything sounds very bland. The piano setting sounds dull like a basic sine wave… anyway to fix that? I read somewhere to try resetting the global settings to zero but I’m not sure what that means exactly or how to do it
@@unpluggedlamp This isn't an issue I had since I had the carts for the original presets. An issue I did ran into when moving over other presets was the first few would come in right, but all the others wouldn't sound right and some had garbled text. My fix to that issue was either something like lowering the transfer speed or increasing the timeout time on the software used to transfer the data.
@@deltamumusic thanks again for your response! I tried that but I still couldn’t get it to sound like it should… I’m not hearing any “Danger Zone” bass hits or cheesey Phil Collins electric piano haha. my keyboard sounds like it starts to make a different sound when going from one preset to the next but the initial sound does out and it just sounds like a dull sine wave. could it be a capacitor issue? I’ve been doing some digging but if I can figure it out I’ll have to have a tech look it over :/
where did you get the capacitors and how do i look for the right ones? oh and how do i know which ones i should replace? or is that just trial and error
I luckily have an electronics store in my area that has a nice collection of stuff.
As for knowing which ones to replace, there are a few things to know. Typically it's electrolytic capacitors that fail. They are the cylindrical one. Sometimes you may see them swell and bust open. Other times they don't show any visual sign of failure. Providing you have proper documentation, you could test points with a meter or scope. I choose to just replace all of the electrolytic caps on the DC board (where power comes in). A lot of the time on older equipment, that's where the problem(s) start. Also since I have a shop near by where I can get parts at a fair price, it wouldn't have made much of a difference to get a few capacitors or all of them.
I'm not sure how ordering that kind of stuff online is like, but I could imagine it being kind of pricey (relative to parts) and that you may possibly have to buy a larger quantity than you need.
7:26 the longer leg is positive (+) careful!
Can you let me know the ratings of all the capacitors you changed please on the sound board . Is it true that a capacitors terminals are positive has a longer wire and negative leg has a shorter wire ? I have the same synthesizer a original Yamaha DX7. Appreciate your responses
I only replace capacitors on the DC board. I don't recall the values off hand, but the ones you remove will be marked with their values. You can swap them with one of equal or greater rating. If memory serves me correctly there were at least 2 I couldn't get exact matches for so I went with something with equal capacitance, but a slightly higher voltage rating.
And yes, it is true the longer lead is positive. Electrolytic capacitors will usually also have a mark labeling one of the leads. Typically it will be for the negative
Thank you. I also have another problem. The led display shows up characters all correctly when I run the synth from the data memory but when I use the internal memory the vocal characters are all distorted and cannot be read. Does the synth need
the factory presets reinstalling ?
@@duncanmartin8965 reinstalling the patches could help, but I have a hunch the internal battery needs to be replaced as well
@@deltamumusic Okay. Thank you . Left it with a music /electronics expert now. He knows about these issues. Hopefully up and running soon as it’s modular. Thanks for all your help 👍🏻
As like yourself all my factory preset voices have been wiped from this DX7 now with the internal battery replaced. Can you give any guidance on how to reinstall them please ? I don’t have midi and heard something about ‘Dexed ’. I also have the original voice cartridges ‘1’ and ‘2’
السلام عليكم لدي اورغ يامها dx7 يفتح ولكن لا يخرج صوت ولا يعمل ما العمل
Hi do you loosed the internal memory when you replace the battery. Do I have to reload the sounds if I do it?
The internal memory gets wiped when the battery is replaced. You will have to reload it with patches. The easiest way would be with the cartridges, but you may want to try it via MIDI.
(keyboardchronicles.com/2020/04/06/uploading-patches-to-your-dx7-on-a-mac-with-osx/)
The link above should send you to a page on how to do that. It is written for Mac, but the process is similar for Windows.
Also don't forget to follow the link at the end of the article to grab a bunch of patches
Thank you very much for the quick and detailed reply! I am going to attempt a restoration! Wish me luck!
Ayuda me sale un 88 en la pantalla y no deja arrancar. Alguien sabe como solucionar
I have a dx7. It doesnt sound too good and the output is a bit dodgey. I can get it to stay on. After a bit of fiddling.❤
Which spray do you use to clean the soldering?
I've been using Gunk Contact Cleaner
Thanks 🙏🏽👌🏼👌🏼👌🏼👌🏼👌🏼
Your welcome
❤
I've been following the Yamaha DX7 Patches on TH-cam videos when I copy them exactly. My Synthesizer sounds way off. Can someone explain to me whats going on? I adjust all the operators according to the videos following all the directions correctly and it still sounds off.
check the breath controller settings
hello what brand of flux are you using?
I've been using Oatey. Not for any particular reason other than it's what I've had on hand for ages.
N° 5
@@deltamumusic
What lubricant are you using
3-in-1 electric motor oil. Admittedly not the best choice, but it was what I had on hand at the time. I would probably recommend something like a silicone based white lithium grease
Помогите купить картридж для DX-7
nice video. the capacitors are pronounced electro-lytic
BAtterie Voltage 2.8 V
Some people should be banned from owning nice things