In January of 2017, Roland Japan released a press release notifying users of SR-JV80 expansion boards to return their boards to Roland due to a risk of the smoking the electrolytic capacitor. This can lead to a catastrophic failure of the board, which can damage the synthesizer.
Before we start…
Replacing capacitors on old electronic gear is generally considered a good practice, and at some point in time a similar procedure will take place for the capacitors in the JV-1080 synthesizer itself. However, vintage gear usually made using through-hole components, were each component has two or more legs that go pass holes in the board. Replacing this kind of component is relatively easy. But the SR-JV80 use Surface Mount (SMD) components, meaning that our capacitor is soldered on top of two copper pads on the board.
Before starting to replace the capacitors, you might want to first check a couple of videos from guys who are a lot more experienced than me showing how to handle this kind of component. I recommend this video from EEVBlog:
As well as this one from GreatScott:
Now that we refreshed the technique, you have two options: one is to replace the capacitor for another SMD capacitor of the same capacity (100uF). Another option is to adapt a 100uF through-hole capacitor. This latter technique is exemplified by the great Don Solaris on this video:
I, however, prefer to replace the SMD capacitor for another SMD capacitor, which will look a lot better, and does not give the board the look of having someone “hacking” it. For that purpose you’ll need a SMD 100uF capacitor rated for at least 6V (my local supply shop only had 25V, but that is fine). More importantly, the dimensions of the new capacitor cannot go much beyond those of the original ones. The original capacitors measure approximately 6.3 x 6.3 x 6.3 mm. The ones I manage to buy are a little bit bigger, but their pads still align properly with the ones on the board, and their height does not exceed that of the CN1 connector (which is approximately 1cm high). These are important measurements to bear in mind before even open the box.
This is a step-by-step account of the procedure I followed when replacing the capacitors on my 4 expansion boards. I’m assuming you are already familiarised with opening the expansion board cover and removing the expansion cards. You can follow them while looking at the video tutorial I placed on my YouTube channel:
For this procedure, you’ll need:
- A soldering iron (preferably a soldering station with adjustable temperature and Philips head shaped point).
- Some tweezers.
- Solder (0.6mm with flux core)
- Solder wick.
- 6.3×6.3×6.3mm 100uF SMD capacitor rated for at least 6V (one for each board). See above discussion regarding the dimensions of the capacitor.
- Electronic board adhesive (in case you lift up one of the soldering pads).
After removing the boards from the synthesizer and having all the components and materials in place:
- Heat the soldering tip to about 360ºC (680ºF).
- Place a small strip of solder wick close to the base of the capacitor (near one of the pads), and press with the soldering iron until the solder is absorbed by the wick.
- Repeat step 2 for the other pad of the capacitor.
- while applying the soldering iron to one of the pads of the capacitor, wiggle it from side-to-side using the tweezers. Alternate the application of the soldering iron between the two pads until the capacitor de-solders from the board.
- Clean the pads of the expansion board with some solder wick. If desired, let it cool a bit and clean with iso-propanol.
- Prime the pads of the board with a little bit of solder, just enough to get two small elevations less than 0.5mm high.
- Prime the pads on the base of the new capacitor with a little bit of solder. For this, you’ll need to have the capacitor upside down, heat one pad with the tip of the soldering iron and touch the pad with the solder until it melts and covers the pad surface. Repeat for the other pad on the capacitor.
- Place the capacitor on the board. Make sure the new capacitor is correctly oriented in the board! Electrolytic capacitors may explode if placed the wrong way around in a circuit! Your new capacitor should have an almost square base with indents on two adjacent corners. These indents should be oriented in the same direction as the markings on the expansion board.
- Secure the capacitor in place with the tweezers while applying heat on one of the pads. The capacitor should sink a little bit as the solder melts.
- Apply heat on the other pad of the capacitor while pressing on it with the tweezers. The capacitor should now sink a little bit to the heated side.
- Finally, apply heat on the first side of the capacitor, to ensure the solder joint is not under stress after soldering the second pad.
Your board is now ready to be placed in the JV-1080 and give you another 30 years of good sounds! :)