Keys, Synths & Samplers

[wesg]

Hey, all;

My main piano is a Yamaha DGX-620, about 5 years old now, played pretty much daily. This is an 88-key hammer action keyboard.

It's been fairly reliable for me, but a horrible problem just developed today.... If I play E and Eb 'legato', only the first one played sounds. If I play them with a bit of separation, or exactly at the same time, they both sound. So, say, I play the introduction to Fur Elise with normal articulation, I only get the E and not the Eb. Only E/Eb are affected, and it happens in every octave.

This really sucks for playing blues in C, my Eb->E crush notes sound like.. well, Eb

Is there anything I can do other than to wait until I can get it into a tech? Is it likely to be worth fixing? I have visions of a failing key scanner IC. I already have a finicky display (common problem), but don't really want to replace it.

[wesg]

*argh* - not just Eb->E, also A->Bb

[1001gear]

Get in there and start jiggling parameters. Could be resettable.

[delaware dave]

I'm not familiar with that model keyboard. Is the operating system reloadable or can it be reinitialized? If it use to work correctly and now it doesn't, and you didn't reset any parameter you may have an OS corruption. If it is possible on that model, I'd try reload/resetting the operating system.

[JohnHKart]

It's not a problem that a magic reset will fix. This model doesn't have an os to load. It's not user serviceable unless you are trained to do this- then you will need to buy the service manual and do it yourself. A qualified servicer needs to repair this. Find them here:


http://usa.yamaha.com/dealers/service_locator/

[Plink Floyd]

Here's the manual, but if your not comfy with such tech I wouldn't monkey with it. If you were comfy with that, or if it were a less expensive board, I'd say open it up and re-seat all the flat mylar ribbon cables that connect the keying boards to the main boards. That sometimes clears up dead notes and such.

JohnHKart is right in saying there's no user serviceable OS. In that board, the microcode (and the waves) is on a non-volatile PROM. If it's not a keying connectivity issue, it's probably trouble in the main CPU, or matrix decoder which is another CPU, and all of the chips are SMD.

[1001gear]

Pg 37/38, initialization and backup procedure. Worth a try?

[Plink Floyd]

That only clears what's in the flash memory, but yeah, it can't hurt. Just make sure to backup all the Style Fyles first.

[1001gear]

Yeah, I was thinking there might be some broken portamento glitched in there or something. I have a D10 with a sticky key switch. Looks like a nightmare getting to the key. I think I'mma end up ignoring it. lol

[delaware dave]

Originally Posted by 1001gear

Pg 37/38, initialization and backup procedure. Worth a try?

+1. Give it a try ...

[the_big_e]

I'm gonna venture a guess and say it's a hardware problem, possibly with the diode matrix (although not guaranteed) that lets the hardware know which keys have been pressed/released.
On my EX7 there's a long circuit board under the keybed with a bunch of diodes on it. It has a similar problem (velocity at full = load sound) for some notes when I play legato. I replaced the board ($200 ouch) and the contact strip but it did not fix it in my case so I am assuming that for me at least the problem is elsewhere.
The question becomes at what point is it not worth it to get it fixed vs just buying a new keyboard.
My ex7 is worth maybe $400 in working cond, pretty much nothing as it stands now and I've already spent a couple of hundred on it. Trouble is for me, I love the sounds it makes so I am hanging on to it for now.

[wesg]

Thanks, guys. I have a CS education and worked as a PC tech in the early-mid 90s so I'm comfortable with this hardware from a conceptual POV, but have no practical domain expertise. I especially appreciated the service manual link, it clears up the lack of options.

I think the plan at this point is to back it up and do a full reset, test it, if it still fails then crack it open, blow it out with air and wiggle all the connectors. I doubt very much any of those things will help, but it's possible in my mind that something unlikely, such as a moist dust bunny in the wrong place, is responsible for this.

If that doesn't work out, I'm going to be sad. I rather like that piano, and don't really want to replace it. I'll try and get an estimate out of the local Yamaha factory guy, but I definitely don't want to drop, say, $500 on a piano I can functionally replace for about $800 (DGX 640).

the_big_e - I feel your pain, replacing a piano that you use for more than piano and rhodes voices means changing your sound. I have a bunch of dual-voice / split programs in this thing that will only "load" on either a DGX-620 or DGX-520. Changing sounds sucks, because I can often burn 6-8 hours auditioning patches and tweaking settings; then sometimes you have to alter your playing style for a tune to get the synth or string patches to do what you're after.

I went through this a number of years ago with a PSR-510; again, not a particularly great piano, but it had a bunch of neat patches that I wove into "my sound". I don't even play in that band any more and I'm still keeping an eye out for a cheap one..

Hey, Can you MIDI up your EX7? My PSR-510 has an option "Local On" which makes a midi keyboard behave as the internal keyboard; this way I can use a generic controller plus the PSR-510's buttons to get what I want...but it's too bulky in that state for stage work IMO.

[the_big_e]

I should try hooking the ex7 up as a slave to see if the problem persists. If it does it's going to be a main board issue, if not then it might still be off in the keybed area. Sometimes though, as sad as it is, you just have to accept that it's only good for a door stop and move on.

[wesg]

It's a miracle!!!!

My keyboard returned to normal all by itself this weekend.

The day this started, it spent overnight in the van. It got pretty cold, maybe some inside condensation? Do any of you guys worry about condensation inside your boards?

[wesg]

Argh -- mysteriously started again this morning.

Man, am I ever bummed. That means I have to open it up, hope I find something obviously wrong, or start keyboard shopping. Which sucks, because I *really* like this thing.