Let's Set Things Straight

And by "things" I mean the knobs on my JX-305.

They're a little bit out of line, particularly the knob for sustain, which is quite noticeably bent towards the keys.

These knobs had clearly taken a bit of a hit at some point.

And they're also kind of filthy, so let's dig inside.

First, the back comes off.

Then the main PCB is unscrewed and moved out of the way.

Then after unscrewing a few brackets we merely lift the control panel free from the... Son of a-

Ok, power switch comes out next, I guess.

Then we can finally pull the front panel board out.

As we can see, the pots are definitely filthy, and they've definitely been bent out of line. Those little legs are supposed to sit flush against the PCB.

I wasn't initially sure if these had been soldered askew at the factory, but looking at the back side it's clear that the solder joint had, at some later point, been deformed by the pins being levered up.

So that explains things.

Also just looking at this picture it seems I failed to notice that the pins themselves need resoldering. Excuse me a moment.

So let's see, where were we... Ah yes, so, flipping the board over, it becomes pretty clear that the pots are out of their proper alignment.

And some of them have even been hit hard enough to start to fold back the tabs on the bottom.

But once those tabs are pushed back into place, and once all the pins are resoldered (ahem, all the pins), things are looking much more straight.

Thanks to these refreshed solder joints.

Which are so shiny that they're basically impossible to photograph. Oh well.

Shoving things back into the case, we can see that the pots are aligned with the front panel much better than before.

And with the knobs on, everything is looking pretty much perfect.

Or at least as close to perfect as I'm gonna get it.

BBrraaiinnss

So it's that time again.

This JX-305 came up for sale with those four sweet words "For Parts or Repair".

The seller indicated that the synth stopped working after they had played a gig on a boat, in which they were forced to leave the synth out in some misty rain because they didn't have anything to cover it with. I was quite confident that the rain had nothing to do with the failure, so I made a bid and it arrived on my bench.

When I powered the synth on, it was indeed dead as a doornail.

The display was blank, none of the LEDs were lit other than the Beat light which was glowing orange (it's only ever supposed to be red or green in normal operation), and basically everything was unresponsive. Not a positive first step.

However, much like the MC-505, which this synth is based on, the CPU has a hard-coded bootloader that you can access by holding down the right keys when powering it on.

The magic combination is to hold down "Mute Ctrl" while powering the synth on, and then tap on "3/High Hat" a few seconds later.

Well that's looking better already. Let's see how far we can get with this.

Well, it's taking data, and...

Hmm, nope, no good. Well, that explains why the main processor isn't booting: if it can't write a firmware image it sure isn't going to be able to read it back either.

Having a peek inside, we can see some big flat-pack chips soldered down with our good friend lead-free solder.

This one in particular is the flash chip that holds the firmware, and I think it needs a little love. So, come along for the adventure and see where it takes me!

I promise it'll be fun. Or, well, it was for me at least.