Cherry M80-3000 help to cure ringing

[davidc]

I have a Cherry MX 3000 USB/G80-3000LSCGB -2 /00.  It was made in Germany but bought in the UK.  It has no Cherry logo on the top left of keyboard.

I like this keyboard a lot because of its clicky keys but there is also a metallic ring from it every time a key is pressed or the keyboard is gently hit on the frame.  It sounds like the sort of ring you get when you hit something metal so I assume there is some metal part inside the case which is causing the noise as a result of a sympathetic vibration.  Cherry have told me they have never come across this before.

You probably might not notice in a busy office but in a quiet work room it is very noticeable.  Has anyone come across this, please?  I'd like to get inside the keyboard to damp down the metal part making the noise but the keyboard has no screws and I don't want to break it forcing it open.

I was a bit surprised it did not have the Cherry logo top left - I assume it is a genuine Cherry G80-3000. The sticker on the back looks real.  If I do not have a genuine Cherry I might by another if it definitelyy would not have the ring.

Grateful for any info on this and particularly on how I can get inside the keyboard.

Thanks

[itlnstln]

You can proabably stuff the cavities in the keyboard with soft foam to dampen the sound.  This is a tactic we used installing car stereos (the speakers, oof course) and it works pretty well.

[davidc]

Yes, that sounds like a good plan  But how do I get into the keyboard to do it?  No screws.  There may be some clever sequence of actions for removing plastic pins or catches but I don't know what it is.  Maybe someone here has done it?

[lowpoly]

I have opened my G80-3000LSCEU, I think two days ago. There are a couple of vertical clips under the front edge and four (?) horizontal ones under the back edge. I use a medium sized screwdriver for the front edge clips. There is a clip on one side and a plastic notch on the other. The clip requires some force. So be sure not to break the plastic notch. I press the case halves open with my left hand and use the screwdriver with my right.

Sounds complicated but in reality I didn't care about clips and notches and opened the case in seconds. It should be obvious where to put the screwdriver.

The back clips can be opened without tools IIRC but a screwdriver won't hurt.

Having that said, there is no metal plate inside. The case is a good resonating body though.

[BigWopHH]

Placing the keyboard in a soft pad, also cuts down on the ringing slightly.  That's what I did with a ASK-6600 that has the same ringing issue.

[davidc]

Thanks very much.  I shall get my crowbar out and break into the keyboard.  I am surprised there is no metal part inside.

Yes, I have my keyboard on absorbent material unfortunately that doesn't affect the inside ring.

Thanks again for the encouraging and helpful replies..

[davidc]

I have to report a fatality.  I got into the keyboard ok but the two multi pin connectors came loose from their sockets and it was beyond me to reconnect them - not least because they were squashed.  So the keyboard has had it.

But..I am not too concerned because it was quite clear from seeing inside it that the ringing comes from the metal structure below every key.  The only way to improve it would have been to stick soft material across the whole of the bottom of the circuit board to which the keys are attached and even that only worked up to a - but it would be impossible to fit the the pcb + the material underneath, back into the case.  There's not enough room for that.

So I have said goodbye to that keyboard.

Can anyone suggest a clicky keyboard that has no ring, please?

[lowpoly]

I have to report a fatality.  I got into the keyboard ok but the two multi pin connectors came loose from their sockets and it was beyond me to reconnect them - not least because they were squashed.  So the keyboard has had it.

That's by design. They are soldered to the switch pcb but just connected to the controller pcb. Just straighten the pins and re-connect. If the cable is broken at the pins you can shorten it. Or solder it. This should be more than easy to repair.

But..I am not too concerned because it was quite clear from seeing inside it that the ringing comes from the metal structure below every key.  The only way to improve it would have been to stick soft material across the whole of the bottom of the circuit board to which the keys are attached and even that only worked up to a - but it would be impossible to fit the the pcb + the material underneath, back into the case.  There's not enough room for that.

There is no metal structure under the switches. What you see is the pcb (made from paper and formaldehyde) which has a copper coating on the top. This copper is 0.00000000something inches thick. It will not ring.

If I should guess I'd say the pcb or case is warped and the pcb touches the supporting ribs in the bottom case not as it should. Try to put some adhesive tape over the ribs.

[CX23882]

Could it be the springs within the switches themselves that are ringing?

[lowpoly]

Could it be the springs within the switches themselves that are ringing?

Good idea but the spring is always under tension. When you open a switch it presses the halves 1/3" apart.

However, when you press a switch and shake it, it rattles. That's the white plastic part around/under the blue stem. When the switch is pressed it can glide on the stem and rattle. It doesn't sound metallic, however. But it can play into the whole noise scenario.

[BigWopHH]

I just pulled apart my Solidtek ASK-6600U, which has the same ringing issue.  I think the problem stems from two issues--the metal plate used to hold the switches is relatively thin (you can bend it in your fingers), and the swtiches are soldered through the metal plate, onto the PCB, and it doesn't appear that anything else is holding the metal plate in place.

If there was a non-conductive, expanding foam you could spray in between the PCB and plate, it should help reduce the resonance, but I'm not sure how / if that would affect the individual swtiches.

As an experiment, I sandwiched some non-condutive padding in around the edges of the PCB and metal plate, and sandwiched another piece between the entire key / plate / PCB assembly and the plastic case, and it helped a bit, but not completely.

If I held the key / plate / PCB assebly in my hand to absord the vibration, and pressed some keys, the ringing was gone.  So, at least in the case of the Solidtek, it's not the switches themselves resonating, but the plate / PCB assembly.

[lowpoly]

The switches in the Cherry are not plate mounted though.

[BigWopHH]

The switches in the Cherry are not plate mounted though.

Well, there ya have it.

[davidc]

Thanks for the encouragement to rebuild.

On my Cherry it is the independent key mechanisms that are ringing.  On checking again to be sure, I found that nothing can stop this ringing because it happens in the key mechanism and is not affected by any damping to the board supporting the key mechanisms.  Even if you jamb a piece of foam (or your thumb) up against the board so it is firmly pressed against the four solders securing a key (on the underside of the board), the ringing still happens when you press down on that key above.  There is no way to stop it.

I'll keep looking.

[lowpoly]

Looks like you have to find a different switch.