The first thing I did was remove the four screws on the top, and the one on the back by the power switch(easily forgotten). This allows you to lift open the top control panel and look at all the fun stuff inside.
The panel is on hinges, and that make life easy because you don't need to disconnect the wires going to the main board.
I know that a key is broken, but I didn't what was broken about it. I assumed it was because a spring or something slipped out of place, but I wouldn't find out until a little later. You can see the broken key below, it is the third black key from the right (F#):
Looking at the innards of the DX 7 my next step was to figure out how to get the keyboard assembly out of the synth so that I could look at the bottom of the keys. There are four screws at the bottom of the keyboard, and they looked more or less like they might attach the keys to the rest of the unit, so the screws came out.
Above is one of the screws. After those are removed, there are three more on the inside of the keyboard that you have to remove, and then the key assembly will be freed. Two are right above the mod wheels, and one is on the other side of the keyboard.
To actually remove the keyboard you will have to disconnect the wires seen above, as well as a ribbon cable and a green ground wire.
And bam, keyboard is free. This is as far as I went. I just wanted to get an idea of what was involved in taking a DX 7 apart. I have a feeling the hard part is actually going to be removing the broken key.
The broken key had a small plastic bit snapped off of it, so it no longer sits firmly in its slot, and wiggles around a lot, and because of this it is not springing back into place. Below you can see the hole where the key should fit in, its the small empty square.
The next step is to order the replacement key and install it. I'm confident that I might be able to do it, but there is a chance that I will have a Yamaha DX 7 for sale, no longer working, good for parts.
Part 2
More progress and discoveries
Part 2
More progress and discoveries
I seen no screws on the top of any of the three DX's I own. ( DX7s, IID IIFD )
ReplyDeleteI sure would appreciate it if you would tell me exactly what screws to remove to lift the lid. All three keyboards need repairs!.
Thanks!
Cat >^..^<
I'll have to check when I get home tonight. I'll post a new picture of the screws.
ReplyDeleteRather interesting to see all this taken apart for the broken key.
ReplyDeleteIf you want a key replacing (i.e. the switch is ok), there is absolutely no reason to remove the keyboard. Remove the 5 screws for the flip cover, the white plastic holder sheath over the back metal and press a key forward for removal. Lift from the back and key is removed.
One thing I will sa is that if people do this, ensure the metal spring on the key is well placed. if not, upon putting the key back in place will be ok, however after a few plays the key may drop (happened to me a few times).
There is NO need to remove the entire keyboard unless you have a faulty switch, wiring .. etc.
Hope it helps.
I've just repaired a DX7II FD with key problems.
ReplyDeleteAfter removing ALL the screws in the bottom cover the power supply
needs to be moved out of the way
3 machine screws in the rear panel and 3 that hold it to the keyboard
assby.
Then remove the 4 screws in the rear panel that hold the main PCB 3
screws that hold the PCB to the keyboard assby AND the 2 screws in
the upper right corner with clearance holes around them
( Some screws differ in size so, make a graphic of which ones go
where)
There are also 2 smaller screws on a bracket beneath the main PCB (
at least on this model) Those need to come out too.
Pull the 2 white mutli-pin cables from the keyb'd assby ( gently)
Pull the flexcable from the floppy drive ( if you have a type FD DX7)
4 long plastic tapping screws hold the corners of the kyb'd assby.
Remove those and remember one is a GND for the kyb'r frame.
There is one more thing , a multi-pin connector on the small PCB
attached to the kyb'd assby. Pull cable there.( This is the gain adjust
board for the velocity and key response circuit)
To remove keys:
Remove the long white plastic back-stop at the rear of the assby.
Push the front of the key you want out and let the back of it pop up
then gently pull the key forward and up. There should be a flat-thin
key spring inside the key. If not , go find where it went to.
Key insertion:
Make sure the cut-out end of the keyspring is down inside the key
and pressed against the bottom of the keystop (in the key)
Let the other end of the keyspring rest at the top of the rear keystop
pin. That end needs to fit into the small indent in the main chassis of
the kyb'd assby.
Fit the front of the new key down and in ( from the front of the of
the assby) so that the 2 "claws" on the new key fit 1st.
GENTLY fit the rectangular bottom tab of the key( at the rear) into
it's hole in the chassis. A bit of wiggling might be needed here.
If it pops down and the key holds like the rest , you're done.
Then replace that long white plastic backstop piece.
You might have to try a few times to get it right but do NOT force it.
Scott audio-fixation.net
Thanks... I did all of that and then went a little further... the keys come out... nothing was broken just somehow stuck in the "down" position... I did tapped it several times with my fingers... gently and voila !!! the key sprung back to it's "up" and ready beauty...
ReplyDeleteput all of the screws tight, (but not too tight), all connections and my dear DX7 is now like new again...
PS: to Cat... there are four screws on the bottom of the keys, short, machine screws and all aligned to the bottom-front...
Great instructions - thx. My own additions after a replacement tonight:
ReplyDeleteThere are 14 (or 16) screws on the bottom of the board. There were 3 different sizes, and I didn’t notice the difference until putting it back on. Not a big deal, but an extra hassle figuring out which went where.
Make sure the cartridge (DX7II-D) is removed, otherwise the PCB won’t lift out. :)
There are _three_ smaller screws beneath the main PCB on the DX7-IID.
I had two places cables were clamped down with ties. I just cut them off in order to get the keyboard assembly out.
Getting the new key in, when the commenter says, “GENTLY fit the rectangular bottom tab of the key (at the rear) into its hole in the chassis.” I’d add - there’s a small, but obvious place where the un-notched end of the key spring slides into the metal of the keyboard assembly. So there’s a small sliding of the entire key towards the back to get that part of the key spring in, after the 2 ‘claws’ have put fitted into their holes. When you’ve got it you’ll know, it’ll just connect like butter. If you’re having to press down at all on the back of the key, you’re doing it wrong.
Another attempt to describe the motion: put the front part of key down first, get the 2 ‘claws’ in, then lower the rest of the key into place, allowing a small gap at the back - then slowly slide the entire key backwards so the key spring will insert itself into the keyboard assembly and it should go in the rest of the way by itself.