Saturday afternoon, got a couple of hours, let’s change the screen in my S950.

Here’s the problem – backlight really dim in the late afternoon light. Even with the curtains drawn it’s hard to get a photo with the reflections. If anything this makes it look more readable than it was.

Let’s take it to bits.

I’m using the (slightly confusing) instructions from the Gearslutz Pimp my S950 thread. I bought a 40×2 display from buydisplay via Ebay – this is the one:

The original screen has a 14-pin data/power connection on the left-hand side, and the backlight power connection on the right-hand side here:

I was just interested to see what kind of voltage was appearing here, but it was hard to measure – didn’t seem to be getting anything much, maybe half-a-volt? Partly I suspected that screen is probably fine, but the inverter is stuffed – here it is, lurking in-place behind the front panel:

The connection on the left is the 5V and 0V connection from the panel – this is what we’ll use to provide the power for the backlight on the new display. The data and power connection for the display uses the bottom 14 pins on the connection, with the 15th and 16th pin taking 5V and ground respectively for the backlight.

As Don suggested in the thread, I connected a 1K pot (albeit linear, it’s all I had going spare) in series with the 5V connection to control the backlight – I nudged it down a bit from the maximum, and it’s probably a bit too bright still but it’s readable.

It took a bit of finagling to get the screen in place – it has to go behind the screw holes because the screen is thicker than the old one. The screws had to go in from the back, which was a bit of a faff.

Here it is with the front panel on:

Looking loads better. Shame about the scratch through the screen, though not much I can do about that. It was only 75 quid when I bought it (including a massive box of discs) so I can’t complain really.

While I had it open I took some photos of the insides. Easy to see the eight voices on the top board.

Getting a bit closer – loads of regulators attached to that chunky heatsink:

Towards the back on the left we’ve got the power inlet, transformer and the MIDI board – PC900V opto represent.

And there’s this bit, caused me some trouble last time.

It’s all back together now and happily propping up a bunch of other relics.

I replaced all the small buttons on my newly acquired MPC1000 the other night, and it was dull but three hours well spent. None of the smaller buttons were much good, with the cursor keys being particularly shit.

I followed the advice in this video, and bought a bunch of Alps SKHHAKA010 switches from Farnell and warmed up the soldering iron. Credit to Farnell, they seemed to have upped their game since I started buying stuff from them – I ordered these switches at 8pm one night along with a few other bits to bump it over the free postage limit of £20, they were apparently dispatched at 9pm (“yeah right” I thought as I saw the email) and I got them the next day.

Here it is with the case off.

Desoldering the legs of each button after I’d clipped them all out was a drag with only desoldering braid, I wished I had a better desoldering pump. Here are the dead buttons, grrr.

In the end it took me three hours in total, and that’s from taking it all to bits and wondering at the solid metal construction, desoldering the old buttons, fitting and soldering the new ones, and putting it all back together again.

Having spent ages looking at ideas for buttons for making my own sequencers, I liked the arrangement in use on the MPC, despite the switches themselves being rubbish. The translucent buttons have an LED just above the tact switch.

Just remains to see whether I get on with the MPC now – it’s been good fun chopping up beats with it so far, would be nice to actually finish a track with one.