Microelectronics | Topre Realforce 104US Keyboard

Synopsis

I just bought this keyboard after twenty years away from mechanical keyboards. I parted with my last mechanical keyboard somewhere in the early 2000s. It was a BTC 53 series with capacitive switches. But let's come back to the Realforce. One thing that strikes me is the presence of blue indicator LEDs for modifier keys. As much as I like the keyboard, I hate those blue LEDs. They violate my retina, especially at night.

Disclaimer
This article is not to be treated as a do-it-yourself tutorial on how to fix, restore, rebuild, or improve this unit. This was not my initial intention. But you can consider this whole content as a general guideline, should you decide to attempt any service procedure on an identical or similar unit.

The entire documentation is just a reflection of my work and I cannot be held responsible if you damage your unit, or even harm yourself in the process.

Maintenance

So I decided to replace all of them with more common green ones. Thus, as soon as I received the package from Japan, I plugged in the keyboard and used it for a couple of minutes or so. Then I opened it up and started the replacement procedure. I have used quality green translucent (clear, tinted) 5 mm LEDs, made by ROHM Semiconductor. They are GaP (gallium phosphide) formulation and emit a yellowish-green light with a wavelength of about 563 nm. I find yellow-green light very relaxing for my eyes.

Just to mention, the original blue LEDs are 3 mm with a raster identical to that of a 5 mm LED. However, they have a weird form factor which I have never seen up until now.

While here, I have noticed there are two SMD electrolytic capacitors on the PCB. As I don't have any schematic and I don't have any time or interest to reverse engineer it, I am assuming these are for supply rail filtering purposes. In my unit, they appear to be made by Nichicon. Or so it seems if I'm looking at the markings. While they are certainly new and might last for a long time, I decided to preventively replace them with solid aluminum polymer capacitors of the same 33 uF / 25 V rating. I suspect even the originals would have lasted for a couple of decades. But I'm kind of afraid of possible leaks. After all, I've seen capacitors leaking in my old Lacie 5big Network 2 Network Attached Storage. Well, those were of weird provenience anyway. I have yet to see genuine Nichicon capacitors leaking.

Since I never turn off my main workstation, the keyboard will always be powered on. Naturally, I expect it to be (electrically) reliable in time. Well, during the night, the workstation is in sleep mode, but the keyboard is still alive.

This was a quick project and I'm pretty happy with the results.

Pictures

Here are some pictures that I took during this operation.

Green LEDs look so much better on classic keyboards.

Nonetheless, this is a clean layout; somebody did the job right.

Old capacitors.

New capacitors.

Detailed view on the Hall effect switches. Well, actually there's no physical switch. The spring, together with the circuit board, act like an electronic switch.

All lit.

In reality, 99.9(something) % of the time this keyboard is in use, the Num Lock LED will be lit.

This keyboard has that classy look.

That's it for now. I am expecting at least two decades of service from this keyboard. Maybe more?