The Z400 blog part 2 – Electric overhaul

Table of content:

Before we get started

Now before I can even start to plug this printer in, I need to be sure that it is safe to power it. The Z400 has been sitting still for half a decade and is already twenty years old. For all I know, a power supply is blown.

What are we looking at

The Z400 is actually a glorified old PC with an inkjet printer attached, and some hardware added to that. It is quite possibly the most amazing hack I have ever seen. “We want a 3D powder and inkjet printer”, and they just took a real existing inkjet printer (not kidding) and built a whole powder handling machine around this. All of this is controlled by a quite normal PC, only with a ISA port to control the actual movement of the machine. It is the way a hacker nowadays would do it, only in this case a million dollar company was founded around it.

The PC insides of a Z400


The most fragile and least replaceable part is the hard drive. This holds the DOS OS and some software that controls the Z400. If the hard drive is broken without a backup, I can kiss this whole project goodbye.

The hard disc is mounted in the back of the machine. Getting it out is quite simple. Getting an image of the drive was a bit more difficult since it uses an older HDD connector. Luckily the Tkkrlab has a lot of junk, and IDE to USB was quickly found.

And the good news, someone had the foresight to replace the HDD (20GB is not normal in late 90s), and the image seems to be good. One worry less.

For those interested, I do now have an image of a Z400, if anyone has need for this I can send it. A TL;DR is that it is essentially an image of DOS, with some Zcorp sauce added.

Too new for 1998

The power supplies

Next are the power supplies. These are around the time a boatload of crappy capacitors entered the market, and even without that issue, capacitors don’t live forever.

All power supplies (2x 24V and 1x ATX) were removed from the back and separately tested with 115V, the machine voltage. The 2 24V power supplies worked fine under load. The ATX also seemed to be stable, though it was more difficult to test under load.

Negative to ground, nice
Testing the power supplies
Test load at 22ohm

To transform, or not to transform

One question remained. How to power this machine. It is an American machine, taking 115V, but I live in the Netherlands, at 230V. The power supplies can all be switched to 230V, no problem. The only issue is that a main board takes the 115V and spreads it to all power supplies. Would I modify the power supplies, or just add a Transformer.

An important part of my decision was made with the manual of the Z400. Here it clearly stated that the 115V machine was 136kg, and the 230V machine was 150kg. The only way this is possible is if the 230V machine has a transformer. A 500VA transformer almost perfectly matches this weight. If Zcorp did not bother simply switching the power supplies over, neither will I. It is very possible that a company selling a monopolized machine goes for the simple solution, but I will not take the risk if I do not have to.

The transformer in question is a nice Riedel 500VA transformer that goes from essentially everything to either 230V or 115V. Exactly what I need. It was mounted in the base, taking the power from the original socket and converting it to 115V before it goes to the main board. There were some flashy accidents with a wire coming loose, and shorting to ground, but other than that, the machine was ready to be turned on.

The board spreading the 115V around
A shiny transformer
Hacked in the printer
Time for testing


And what happened when we hit the switch? First all leds in the machine came on, then…


The PC does not seem to boot. When we attach a screen, we see nothing, when we attach a serial port, no response. There is light though, and an image on the HDD.


This is where to story ends for today. It was getting late, and any next step would take hours. The first step is to take the ISA card out (it is in the way) and see what type of post codes the machine is sending. We are already looking for an ancient PC with an ISA port as a potential replacement. We have everything we might need to make this work. In the next post I will either have something to work with, or a much bigger project.

Until next time.

Posted in Blog, Z400.

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