So this is now fixed... I thought I'd add a guide in case anyone else comes across this thread who needs it.How to replace a panel switch on a Roland FP-31. Assess whether a new switch is required
If clicks only register when you press the button hard, the switch needs to be replaced. I took one of the old switches apart, and here's what it looks like inside. There appears to be wear on the bottom side of the spring disc in the middle. 2. Obtain a new switch
Part number from Roland is 01340290
. They charged £0.83 each + £3.99 handling + VAT.
You can also get the part from a 3rd party: it is a Panasonic EVQ11A05R
. I couldn't find anywhere in the UK (except Roland) that stocks them, and it would be £12 per order to import from USA.
You could use a substitute with simlar specs (datasheet
) - basically a 6x6x5 mm tactile switch with 2 legs and 1 N force (100 gf). Most of the switches these days seem to have 4 legs (for stability?) so maybe this is why these are a bit hard to get hold of.
From the datasheet it seems the EVQ11D05B
has the same specs but 10x the operating life, so get that if possible!
The Omron B3F-6020
looks very similar (datasheet
), has a long operating life, and is stocked by Farnell in the UK.3. Practice soldering!
If you haven't done much soldering before, I suggest watching the linked videos on desoldering
and basic soldering
. Then find some old elctronic item and practice desoldering and reattaching some components (I used an old XBox remote control).4. Unplug everything and place upside-down on a wide workbench / table / floor. 5. Remove the 7 silver screws along the border of the upper casing
DON'T remove any of the other screws on the rear side. 6. Remove the 4 screws along each side on the bottom of the case. 7. Open the casing
The keyboard and upper casing are now attached only by a couple of flimsy wires. To open, I suggest carefully turning the whole thing over (remember the keyboard is no longer supported by the sides!) and lifting the top / sides back. Don't stand them upright, since it's not steady and if one side falls it could break the connectors. (Yes I did that... oops... fortunately the wire and the ribbon connectors pulled out of their sockets rather than broke.) 8. Detach the Panel Board
The panel board is in the middle, containing the display panel and controls. Bend up the three black wire holders and release the wires along the bottom. Remove the 12 silver screws along the top and bottom of the board. 9. Power up your soldering iron 10. Desolder the switch connections using the iron and pump
I'm right handed and found it best to hold the iron in my left hand, and pump in my right, as you need to be very quick to suck up the solder. Then you should be able to detach the switch by giving a little tug / wiggle, if necessary melting any remaining solder with the iron while you tug it out. 11. Solder in the new switch
Take your replacement switch and cut off all but about 4 mm of the legs.
Insert into holes, ensuring you have it the same way round as the others. When in place, bend the legs along the track of the wire, then solder. Once attached, you'll probably see the switch is not flush with the board and exactly centred, so apply pressure to the switch with your free hand and re-melt the connections so it sits properly in place.
(Not the prettiest of joints below, but I think it's because I used lead-free solder, unlike the 60/40 tin/lead I used in the joints on the left above... but hey, it works) 12. Power up the board and test the new switch with your finger
The relevant LED should light up or change colour or do whatever it normally does.
No, you won't electocute yourself since the power supply is low voltage.13. Re-attach the Panel Board screws and test
Put the screws in lightly at first, then tighten when they're all in place.
Test ALL the buttons several times. I found that sometimes a couple of the buttons would stop working properly when I re-attached the panel, but it seemed to be that maybe it wasn't quite centred over the external buttons. Unscrewing the board, checking the switch with my finger, and re-attaching the board made it work fine again. Power off and unplug.14. Re-assemble and re-attach all screws removed in steps 5 and 6
And you're done!
Time taken: 71 minutes. But probably half that if I did it again...