Elektron MachineDrum Mk1
This time, an Elektron MachineDrum Mk1 drum machine came to the service bench. The goal was to replace the original graphic display, which had lost contrast and could no longer be adjusted properly. I thought to myself: piece of cake! A moment later, I realized how wrong I was.
First of all, although the instrument has a very solid construction and is generally easy to service, the manufacturer — for some reason — glued the original display to the front panel PCB in two places, and in two different ways. Instead of using proper spacers and mounting holes, they poured a large amount of hot glue between the display PCB and the panel PCB. On top of that, they used a strong adhesive (something like cyanoacrylate) to glue the goldpin connector to the display PCB. As a result, disassembly was difficult and risky, even with all the right soldering tools. I have no idea why they did this, especially since the board had proper holes prepared for professional mounting. I’ve seen the same setup in many pictures online, so this wasn’t an isolated case.
And now the worst part: the original Winstar WG12864AB-RYH-V#S001 display was discontinued in 2006. When I contacted Winstar’s helpdesk, they told me that the display often recommended online — model WG12864AB-TMI-V#N (blue) — was not fully compatible, because it uses a different display controller. The original version used AX6107/AX6108 controllers, while newer models use NT7101/NT7108, which have slightly different timing requirements for control signals.
Interestingly, Winstar no longer has documentation for the old model — they said it was deleted. Unbelievable. How can you trust a company that destroys its own technical documentation? Ironically, I’ve used many Winstar displays in my past projects for the Elektronika Praktyczna magazine. In Poland, they’re supplied by Unisystem.
After some investigation, I found that both controller pairs are actually compatible clones of the original KS0107/KS0108 chips (which is even reflected in their names). Still, Winstar didn’t confirm this, so I had to experiment.
I ordered a display with NT7101/NT7108 controllers, but it didn’t initialize properly. Then I bought another display, this time directly from Winstar, and it worked right away. I only had to adjust the contrast settings slightly.
Finally, I improved the display mounting (replacing the amateur method with a proper professional one) and cleaned the PCB. So, in the end, this seemingly simple repair turned out successful.
