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Anyone ever opened an RD-700GX?

Posted By: blueston

Anyone ever opened an RD-700GX? - 02/20/11 03:37 PM

I'm looking for help disassembling a Roland RD-700GX. I've opened a couple keyboards in my day, but this one has me a little stumped.

Also, it's a very valuable instrument so I don't want to just start pulling every screw out of the thing to see what happens.

There are screws under the front (which didn't release anything), along the bottom, and tons of different ones along the back. Some are probably holding circuit boards on there.

If anybody has taken one of these apart please please send me some idea of how you did it.

Thanks so much!!!
Posted By: dewster

Re: Anyone ever opened an RD-700GX? - 02/20/11 04:41 PM

Bring on the "Nekkid Pikshures"!
Posted By: hpeterh

Re: Anyone ever opened an RD-700GX? - 02/20/11 04:50 PM

Possibly this helps:
http://www.youtube.com/watch?v=CwezvnqV6Z0
Read the comments in this video. Another guy reported success using the same method for his RD700SX.

There are much more videos. Possibly send a message to one of the posters.

Posted By: qwert

Re: Anyone ever opened an RD-700GX? - 02/20/11 06:32 PM

Hi.
I didn't disasslemble RD-700GX, only FP-8. I understand that they far apart in the body design department, but a bit of info is better than nothing.

Screws along the front line normally keep front part of keybed and should be touched only once the body is opened. This is because back side of keybed is kept by the screws accesseble from inside.

Check screws along the left and right sides first. If there 4 on each side then chances are it is similar to my FP-8. Take them out and then top part pivots back on the hinges ( just like laptop screen opens up, goes up and then towards the back).

HTH, qwert.
If nobody answers
Posted By: Aidan

Re: Anyone ever opened an RD-700GX? - 02/20/11 06:41 PM

I'm presuming you're undertaking this exercise to fix a fault. However, unless you really know what you're doing I would urge you to take it to a Roland-authorised repair shop - the GX is a relatively new instrument and you could inadvertently knock a whole load off its value!
Posted By: hpeterh

Re: Anyone ever opened an RD-700GX? - 02/20/11 08:17 PM

@Aidan:
I think any adult person should know what he/she can do and what not.
There are many technical skilled or trained persons here, many of them do much more critical work -partially even potentially dangerous or very expensive- at job.
Of course without previous experiences and without technical knowledge and talent nobody should do this.
Just remember, the OP wrote, he has experience.
Posted By: dewster

Re: Anyone ever opened an RD-700GX? - 02/20/11 09:06 PM

Originally Posted by hpeterh

That video is really an interesting watch, thanks! That same guy puts speakers inside of drums for feedback & tuning, pretty nifty.
Posted By: Aidan

Re: Anyone ever opened an RD-700GX? - 02/20/11 09:19 PM

Originally Posted by hpeterh
Just remember, the OP wrote, he has experience.


Actually, what he said is that he's opened up a couple of keyboards. That doesn't really tell us anything about experience or competence. Nor has the OP told us why this operation is necessary.

The OP may, for all I know, be an extremely competent electronic technician. However, speaking as a first-rate bodger with no technical or practical skills, I can say that often something undertaken with the objective of saving money on a qualified tech can end up costing considerably more.

I'm presuming the board in question is out of warranty.
Posted By: hpeterh

Re: Anyone ever opened an RD-700GX? - 02/21/11 08:14 AM

Yeah, compared to oldfashioned tape recorders,vinyl phonoplayers, videorecorders these keybords are noncritical and trivial to handle and repair.
Dont see any problem. The biggest problem is to get service information and parts.
It is well known that hammers break often on this older roland keyboards.
If you give it to a professional he will replace the hammers and this will happen again and become very expensive.
Be sure, if I did this myself, I wouldnt even bother to buy new hammers. I would repair and treat all hammers in such a way that they never again will break. Such service is unpayable and you never get this from a professional ;-)

If you /can/ do it, do it.
If you /cannot/ do it, dont do it.

I see a problem if nonskilled people repair their cars or motorbicycles, but not with these keyboards.

Best,

Peter
Posted By: qwert

Re: Anyone ever opened an RD-700GX? - 02/21/11 02:00 PM

Originally Posted by hpeterh
I would repair and treat all hammers in such a way that they never again will break.


I actually would like to know how to fix broken hammer. It breaks at the narrowest place ( like a neck ) and seems impossible to fix. Glue wouldn't hold it as the stress in this place is too high when pressing the key hard enough.
qwert
Posted By: blueston

Re: Anyone ever opened an RD-700GX? - 02/21/11 03:29 PM

Thanks for all the advice guys. I managed to open it up AND found my problem (I won't go into it too much, it's a long frustrating story).

Btw- I am an Electrical Engineer but I'll be the first to accept that doesn't necessarily mean anything!

Hpeterh, I did see that video before but wasn't sure the A90 would be anything like the RD series. Well it turns out it's exactly like this. Basically, you just remove all the screws on the bottom and magically the top will just peal back and fold out of the away. It's actually very easy.

Dewster- Ha Ha Ha. I wasn't planning on posting pics but if you guys are really interested I will.
Posted By: Melodialworks Music

Re: Anyone ever opened an RD-700GX? - 02/21/11 03:57 PM

Originally Posted by blueston
I wasn't planning on posting pics but if you guys are really interested I will.


It would be interesting to see. (Hopefully Dewy won't get to worked up).
Posted By: dewster

Re: Anyone ever opened an RD-700GX? - 02/21/11 03:58 PM

Originally Posted by blueston
Btw- I am an Electrical Engineer but I'll be the first to accept that doesn't necessarily mean anything!

Hey now, speak for yourself! smile

Originally Posted by blueston
Basically, you just remove all the screws on the bottom and magically the top will just peal back and fold out of the away. It's actually very easy.

You have to remove all of the screws?

Originally Posted by blueston
I wasn't planning on posting pics but if you guys are really interested I will.

I'd be very interested in any close-up pix you can post of the processor board and the key action. You can upload pix to PW here:

http://www.pianoworld.com/Uploads/fileuploader2.html

Any IC numbers you can glean would be a big plus too.
Posted By: hpeterh

Re: Anyone ever opened an RD-700GX? - 02/21/11 06:54 PM

Originally Posted by qwert
Originally Posted by hpeterh
I would repair and treat all hammers in such a way that they never again will break.


I actually would like to know how to fix broken hammer. It breaks at the narrowest place ( like a neck ) and seems impossible to fix. Glue wouldn't hold it as the stress in this place is too high when pressing the key hard enough.
qwert


I have a proprietary process to do this.
The principle is to implant a steel needle into the plastics with the soldering iron and fix it in place with epoxy.
Maybe glassfiber armed epoxy.

I cannot give advice because I must see and touch the part before doing it. But I done this for many broken plastics parts on taperecorders and else before and after repair it is better than new ;-)
It is basically the same as chirurgs "repair" a broken bone and I stole the idea from them ;-)
Best,

Peter
Posted By: blueston

Re: Anyone ever opened an RD-700GX? - 02/22/11 03:33 AM

Ok here goes. First the Disassembly. Dewster you are right, you don't need to remove every screw along the front, only the ones in the corners and under the pitch bend.

Follow these directions carefully-

Step 1. Ask your wife if you can use the dining room table as a workbench.

Step 2. Ignore her eyeroll and continue.

Step 3. Lift the keyboard on its back side so you can remove all the screws on the bottom along the back and sides EXCEPT leave a few screws in the corners and the middle (I'm not saying the side method is best practice but this way you don't have to worry about resting it on the keys or snapping off a knob. But be careful it can easily slip in this position due to slanted back.

Step 4. Lay it back flat on the "work bench" but let it overhang a couple inches. Now remove the remaining screws in the corners and in the middle (pivot it around as necessary). It's about 15 screws in total.

Step 5. Grab the sides on top and tilt back the whole top panel (slide it back a little first if you want). Put something behind it so it doesn't tip all the way over.

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

More pictures coming ...
Posted By: blueston

Re: Anyone ever opened an RD-700GX? - 02/22/11 03:53 AM

Ok here are some shots of the main CPU board.

[Linked Image]

[Linked Image]

[Linked Image]

Hey look! Room for expansion... crazy
[Linked Image]
Posted By: Kawai James

Re: Anyone ever opened an RD-700GX? - 02/22/11 03:53 AM

Nice. wink

Did your wife shoot the pics?

James
x
Posted By: blueston

Re: Anyone ever opened an RD-700GX? - 02/22/11 04:05 AM

Yes. In fact I forgot to include those as steps in my procedure. Thanks for the reminder.

Step 2 and a 1/2- Ask wife to take pictures of you as you disassemble it.

Step 2 and 3/4- Ignore facial expression and another eyeroll and continue ...

Lastly- here are some pictures of the action. I'm not an action expert like some of you other guys that appear to have some kind of Masters degree in orbital physics with a minor in keyboard mechanics. Hopefully I have taken pictures of the right stuff.

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

[Linked Image]

Dewster, I hope you still have your pants on laugh
Enjoy!
Posted By: Melodialworks Music

Re: Anyone ever opened an RD-700GX? - 02/22/11 04:30 AM

Wow. Great photos. Compliments to your wife.
Posted By: dewster

Re: Anyone ever opened an RD-700GX? - 02/22/11 03:46 PM

Blueston, thanks loads!

From the pix it looks like the screws along the front hold the key assembly down to the bottom board.

Taking some rough relative dimensions from your pix, that bottom board looks like 1/2" aluminized chipboard. On-line, I see 12mm x 4' x 8' chipboard weighs 23 KG. This board on our NX looks to be around 1' x 4.5', which means it weighs around 3.2 KG or 7 lbs - it would be an interesting experiment to replace this with something lighter.

It looks like the the metal key base is stamped steel, but then the key hinge in the back is a plastic assembly, which seems less rugged. I see some kind of milky grease on the plastic hinges of both the keys and the hammers.

It looks like the keys bottom out against the black foam, there is a foam sandwiched bar of some material in the back that the hammers hit, and the hammers rest on foam as well. It might be possible to reduce key thump by changing the foam at these points.

-----------
- The ICs -
-----------
- Spansion S29GL128 - 128Mb NOR Flash (8Mx16 or 16Mx8) 90ns
- ESMT M12L16161A - 1M x 8Bit x 2Banks SDRAM
- ESMT M12L64164A - 1M x 16Bit x 4Banks SDRAM
- Samsung K4S281632K - 2M x 16Bit x 4Banks SDRAM
- AKM AK4396VF - stereo 192kHz 24bit delta-sigma DAC
- Altera MAXII EPM240T100C5N - tiny FPGA (240 logic elements)

Of the assorted Roland parts, I couldn't find any web match, but either R03679356 or R04670467 is the main processor.

I find it interesting that the only Flash (in the pix anyway) is 16MB - probably for the OS and not samples?

I also find it interesting that an Altera MAXII is in there, not the cheapest of parts. When you're likely doing processors in ASICs, adding even a low-end FPGA must kind of hurt the budget. The stuff I used to design always had a part like this (I prefer Lattice for these catch-all / glue / insurance functions) but cost wasn't as sensitive as it generally is for consumer grade products.

Anyway, I see room for improvement in both the physical and electrical design, though I'm sure this is pretty typical of most DP manufacturers offerings.
Posted By: hpeterh

Re: Anyone ever opened an RD-700GX? - 02/22/11 05:53 PM

Now, my instinct tells me, some elastic foam or wool or other damping material in the red marked cavities should dampen the resonance of the metal chassis and PCB and reduce noise:
[Linked Image]
Of course experimenting is necessary.

Thanks to blueston for these very fine images!
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