My Roland D50 Keys

[KennaOkoye]

Hello everyone.

When I press one of my Roland D50 Keys the Velocity is all the way up, and there is no change in velocity

When I press another key, it does not sound, but when i press it hard, it's in full velocity. What do I need? Do I need new KEYS? or CONTACTS? I have a person here who has a bunch of parts! Thank you for your help

[rhino]

Welcome to the board !

Since only two keys seem faulty, my first guess is that the contacts on those two keys are bad, or out of place.

The worst case is the custom Roland chip on the keyboard control board (located under the keybed) is bad....the only choices then are (1) use the D-50 via MIDI and (2) keep an eye out on Ebay for another dead D-50 you can get the chip out of.

[KennaOkoye]

Do you know what that chip is called?

and if it's the contact, how do I check for them?

[KennaOkoye]

are you talking about LA Chip (88-Pin Version)?

[Nightdare]

Do you know what that chip is called?

and if it's the contact, how do I check for them?

Don't panic just yet, I would thing a blown chip would give trouble over ALL the keys

If you're a little handy with a screwdriver, alcohol and Q-tips, you can find 'alike' tutorials on the internet for cleaning a keybed

[rhino]

Do you know what that chip is called?

and if it's the contact, how do I check for them?

The two possible chips are 6116ASP-12 (rom) and 63H149 (gate array) both custom programed by Roland.

Cleaning the key contacts requires the complete tear-down of the keybed assembly. Maybe not something you should try for a first-time synth repair. If you do, check the rubber cups and rips,tears and sticky goo. Clean the contact board (where the rubber cups were) with alcohol. Inside each cup, you will see two contacts - one taller, one shorter. Check to see none have seperated from the cups, are full of crud, or are worn down to very close to the same height - this will give a note with near maximum velocity. The velocity data to the synth is derived from the fraction of a second difference between the time the longer contacts touched the board and the time for the shorter.
This data is processed by the chips on the Dynascan board (under the keybed) and sent to the main board.

[KennaOkoye]

Thanks a lot guys the symptons I am reading aboout doesn't sound like a chip problem.

[Don T]

Thanks a lot guys the symptons I am reading aboout doesn't sound like a chip problem.

True. A scanning chip problem would affect the same notes in every octave.

The bad news is, rhino is correct. I've never worked on a Roland synth that uses rubber contacts that didn't require complete disassembly, at least in the affected area. Most scanning keyboards have contacts that come in sets of 6, with a set of 7 on one end, so if you want to work on just one key, you're going to be taking at least 6 keys completely off the keyboard. If you're lucky, both bad keys will be on the same strip. In facts, odd of that are good, because I bet you a dollar they are both within an octave of middle C.

Quickest fix: Take the contact strip that is causing trouble and swap it with an identical one from either the very top or the very bottom of the keyboard, especially if you never play up (or down) there, as those contacts take the least abuse (Hint: That's why I made the bet that your bad keys are in the middle of the keyboard).

Not-so-quickest fix: The key contacts need to be "leveled". The cause of 90% of key triggering problems are the fact that the repeated striking of the contact against the circuit board wears away the contact where it meets the two conductive areas on the circuit board, until the point that the pattern of the circuit board becomes imprinted into the contact. If that doesn't make sense (it is kind of late as I'm typing this, insomnia strikes again), simply look at the bottom of a worn contact, and you will see a mirror image of the area of the circuit board it touches. The problem when it gets that way is the non-worn area gets tall enough to keep the contact from being able to bridge across the two conductive traces on the circuit board, unless you press the key REALLY hard. So, leveling the contact means to burnish it with a good-quality rubber eraser (NOT the kind with an abrasive imbedded in) until the surface of the contact is once again flat and no longer shows the mirror image of the circuit board. The contact itself (the little black cylinder) is also made of rubber, a kind that conducts electricity, so leveling the contact is a bit tricky since it is constantly flexing as you try to rub the eraser against it. Be patient and go slow. Luckily the contact strip is a bit sturdier than it looks, so go ahead and make sure you have a good grip on the contact. The contact surface MUST be parallel to the circuit board when finished, and not slanted at an angle. Under NO circumstances should you use a solvent to clean the rubber contact strip, ESPECIALLY do not use alcohol (unless applied internally after the job is completed ). If the contact strip shows any tears as rhino described, replace it, period.

Better fix: All the key contacts will behave this way eventually, so do them all while you're at it. C'mon, it's only 176 contacts to level! Seriously, it's better to get it over with all at once, since you will not feel like taking the sucker apart again should another contact go bad a week later.

Best fix: If you can find all new contact bubble strips, replace them all and you won't have to worry about it again for another 20 years. No, it's not cheap (assuming you can even find the parts). However, when someone brings a keyboard to me and wants all the contacts fixed, it is in fact MUCH cheaper for labor to go ahead and swap the contacts vs. polishing all 176 of the little beasts.

HINTS: If you do choose to take the keyboard apart, if the D50's keyboard in anyway resembles any of the Juno or JX-3P keyboards, don't lose the little adhesive strip of plastic that prevents the keys from sliding out of the frame, and avoid removing/replacing the key springs in a thickly carpeted area (Please do NOT ask me how I know this ). Also, remove the end of the spring from the KEY first, then from the frame, and replace the end of the spring in the FRAME first when reassembling (again, please do not ask me how I know this ).

Good luck! The process is not as bad as it sounds, it's just tedious and requires careful attention!

[rhino]

Welcome, Don T !


KennaOkoye, why don't you give Roland a call Monday: 1-323-890-3740

The part numbers for the rubber key contacts are
12-note set : 22185218
13-note set : 22185219

There is a SMALL chance they will have some.

[Nightdare]

HINTS: If you do choose to take the keyboard apart, if the D50's keyboard in anyway resembles any of the Juno or JX-3P keyboards, don't lose the little adhesive strip of plastic that prevents the keys from sliding out of the frame, and avoid removing/replacing the key springs in a thickly carpeted area (Please do NOT ask me how I know this ). Also, remove the end of the spring from the KEY first, then from the frame, and replace the end of the spring in the FRAME first when reassembling (again, please do not ask me how I know this )

With my JV-90 it was easier to use a stiff hooked piece of wire and 'unhook' from the frame first while keeping a finger on the key's pin

If I were to believe the Service manual, the D50 has different springs for the black and white keys so keep them seperate

Here's a pic tutorial http://www.bustedgear.com/repair_Roland ... tacts.html

[Don T]

HINTS: If you do choose to take the keyboard apart, if the D50's keyboard in anyway resembles any of the Juno or JX-3P keyboards, don't lose the little adhesive strip of plastic that prevents the keys from sliding out of the frame, and avoid removing/replacing the key springs in a thickly carpeted area (Please do NOT ask me how I know this ). Also, remove the end of the spring from the KEY first, then from the frame, and replace the end of the spring in the FRAME first when reassembling (again, please do not ask me how I know this )

With my JV-90 it was easier to use a stiff hooked piece of wire and 'unhook' from the frame first while keeping a finger on the key's pin

If I were to believe the Service manual, the D50 has different springs for the black and white keys so keep them seperate

Here's a pic tutorial http://www.bustedgear.com/repair_Roland ... tacts.html

Hmm, weird, the keys are just like Juno keys, but the metal frame is totally different where the springs attach. That accursed adhesive plastic strip is the same though.

I cannot believe the guy recommends cleaning the rubber contact tips with alcohol! Try that with the rubber parts of someone's expensive reel-to-reel tape deck, and not too long after they are either coming back with a baseball bat or a demand for a new pinch roller (or both). Alcohol can dry out most types of rubber and take away the elasticity. I wouldn't dare try it on a key contact myself.

I can't believe he doesn't level the contact either, you can plainly see the imprint of the traces on a couple contacts. To be fair, in the case of the online tutorial, that particular keyboard appears to be more the victim of a spilled drink rather than contact wear. KennaOkoye, if your key contacts look like the ones in the tutorial, you may be able to get by with simply cleaning them. I use a mild soap and water mixer for that, or you can try alcohol. It may be possible alcohol doesn't attack that particular rubber formulation, I just never wanted to chance it (pinch rollers are expensive, and baseball bats hurt).

If you open your keyboard up, and it looks clean (except for normal dust), and still looks clean underneath the contact strip except for what looks like little tiny carbon crumbles (which is basically what they are), either level the contact or replace the strip.

Thanks for the link Nightdare, I almost exclusively work on analog gear, so I haven't seen the inside of a D-50 yet. I have made a housecall for a cranky Clavinova keyboard before. Luckily for them, but kind of disgusting for me, all I had to do was remove the goo from the orange Jolly Ranchers that was making the keys intermittently stick .

[rhino]

I cannot believe the guy recommends cleaning the rubber contact tips with alcohol!

Sorry if lead you wrong. I use 98% alchohol to clean the CARBON CONTACTS inside the cups, and the conductive pads on the PC boards.

You'd realy moan if I told you some times I use a quick, gentle brush with 1000-grit wet-or-dry paper.

sounddoctorin.com sells adheasive conductive 'dots' that will save synths with key contacts that have one or two round (about) 3mm contacts - not the Casio/Akai "bulls-eye" kind.

They (the manufactures) do not put any more conductive coating on the contacts than need be - if they need more than cleaning, it's time to replace.

Almost decided to not put this last line in, but in the frendly, back-slapping spirit of VSE: I cannot believe the guy who has never seen the inside of a D-50 is offering repair advice about a D-50.

[Nightdare]

I cannot believe the guy recommends cleaning the rubber contact tips with alcohol! Try that with the rubber parts of someone's expensive reel-to-reel tape deck, and not too long after they are either coming back with a baseball bat or a demand for a new pinch roller (or both). Alcohol can dry out most types of rubber and take away the elasticity. I wouldn't dare try it on a key contact myself.

Alcohol evaporates in seconds
Now I won't recommend to dip rubber into alcohol and soak it for a while, but 'surface use' (wiping clean) it won't have enough time and thereby strength to do damage

I don't know what kind of rubber R2R tapedecks use, but if they are porous and able to suck up liquid like a sponge I could imagine it affecting and destroying the rubber, since it cannot dissipate fast enough
The rubber used in keybeds does not strike me as porous

[Don T]

Sorry if lead you wrong. I use 98% alchohol to clean the CARBON CONTACTS inside the cups, and the conductive pads on the PC boards.

I read you correctly, but every key contact like that I've ever seen was carbon-impregnated rubber, not a pure carbon disc like Sounddoctrin has found, although those things sound like a pretty good idea

You'd realy moan if I told you some times I use a quick, gentle brush with 1000-grit wet-or-dry paper.

Actually, I wouldn't, I've done similar many times!

They (the manufactures) do not put any more conductive coating on the contacts than need be - if they need more than cleaning, it's time to replace.

I've found as long as the black conductive rubber is there, you're ok as long as a significant about of the old surface isn't removed. If I think it may be an issue later, I'll re-coat the contact.

Almost decided to not put this last line in, but in the frendly, back-slapping spirit of VSE: I cannot believe the guy who has never seen the inside of a D-50 is offering repair advice about a D-50.

If you only knew how many of those ^%$#@$^%#& carbon/rubber-contact keyboards I've had to rebuild! The only thing worse is having to adjust the metal key contacts inside a Polymoog. Yes, I'm insane, I'd rather adjust J-wires

[KennaOkoye]

I think the first mishaving key is to the left of the middle C, but there are 3 keys in total, one doesnt sound at all, farrr right, towards the end, one that only plays if I hit it hard, and one that will play at a set velocity, which is all the way up.

Check out what I found

http://www.bustedgear.com/repair_Roland ... cts_2.html

I bought this Roland D50, from the sketchiest person EVER! he knew nothing about the board, he was asking 300. there was NO power chord, I couldn't even test it out... I was sure that it wasn't going to work when I got home. Worse part about it, is that, I handed him 160$ before I picked up the board to find out, that there was something moving, like a screw inside the board... as I continue to walk away i heard something heavier moving LOL I was for sure this board WOULD not work when I got home! I got home, opened the board. It turns out that it was the power cell that was loose! so I found that screw and screwed it back on. I then plugged it in, saw it needed a new battery. So i bought a new one, and prayed, turned it on, loaded the sounds from Roland.com, and voila! working!!!! hahaaaaa So, to be honest, Im glad it's JUST the keys that are acting up... looking back, I could have gave him like 100 bucks... but w.e... it works tho...