How to cheaply fix a faulty encoder/value/jog wheel on the VG-88 (maybe VG-99)

[pickupwinder]

I realise there isn't much going on in this section because the VG-88 and 99 are old tech but at least this will show up in search engines if anyone has the same problem I had. I bought a VG-88 recently but the value wheel  encoder was very worn and unpredictable.Not ideal because my VG-88 is a V1 so I can't even use the VG-88 editor software as a workaround.

I searched online for a fix and the only thing I could find that was remotely close was this fix for a Yamaha SU700.
http://www.albates.com/yamaha-su700-encoder-repair-and-replacement/
Because the part number was very similar I thought I'd try it. The Roland part number is 01013223 but it's actually a Panasonic part - number evq-vem-f01-24b. The fix works perfectly. I used the Alps EC12E2420802 encoder which is nice and positive. It's a cheap part, under £4 inc. delivery on eBay UK.

This is not a project for someone who is new to teardowns and has little soldering experience but it is relatively simple. The only gear you need is a soldering iron with a tip suitable for pcb work and a desoldering pump.

To open it up undo the screws round the edge and the two in recesses, leave the three large ones in line and four in a square. There's one other on the back panel above the power lead and switch. There are different types of screws throughout and some have slightly different lengths. You will struggle to reassemble the VG-88 and get the control switches to work properly if you don't make a note of what screw goes where.

Remove the mainboard by pulling the connectors (one disconnects at the other end), unscrewing the inputs on the back panel then all the board screws.  Below that is the panel you want which has two sections wired together. To remove it prise off the Value dial on the front with jeweller's screwdrivers or similar on either side, unscrew the shaft  and pull off the "level" knob then remove the screws on the board. You are now ready to do the fix.

Once the old encoder was removed I found it easiest to solder the wires to the pcb first. I'd also recommend snipping the terminals on the new encoder close to the thicker part after bending them as it makes wiring easier. Next solder the encoder body mounts to the pcb, then the wires to the terminals.

The new encoder did not come with a washer and nut but the old ones are the same size. However you definitely need to add another nut or at least 3 spacer washers to the bottom (internal) end of shaft, otherwise it pulls down the fascia and the "PAGE" buttons lock. Also the opening is a tight squeeze so widen it with a file it or a 9mm drill bit.

That's it I guess. Observe basic anti-static precautions like touching an earth point before handling the boards, and place them on non-static material. You won't damage your VG-88 if the connections to the encoder are wrong .

[Brent Flash]

Welcome to the group pickupsinder! 

[gumtown]

Thanks for sharing pickupwinder.

I guess from your user name, you might rewind or make new pickups?

[pickupwinder]

Thanks for the welcome messages. The main point about my user name is that I lack imagination not that I fix and make pickups It's good to know there's still activity because I may have stupid questions that need intelligent answers.

[mooncaine]

Thanks for the very detailed instructions about how you fixed, with part number! You just helped out your VG brethren (and sistren). I may never need to know it, but if I do, I'll be searching here first. So will you. Stay a while and hang out. If you have other VG questions, this is the place.

[scrapman]

Very useful tip. Thanks.
and welcome to the group.
Yeah, the vg-88 is old, but still plenty of life in the old dog... certainly is round our house anyways.

cheers