Monthly Archives: March 2020

Troubleshooting Zebra/Eltron Label Printers

This article describes some of the troubleshooting tips I’ve discovered for solving problems printing labels with Zebra Eltron label printers.

Power Supply Problems

Most of the label printers you get on eBay come without power supplies. However, other sellers have power supplies that are claimed to be for these printers available for $10 or so, and I’ve bought a lot of them. Everything has been fine until recently when I started having printers fail in a way that points to the power supply.

Some Background

The original OEM power supplies were big bricks rated at 14VAC and 4A. Much to my surprise the power supplies from eBay are rated at 20VDC at 3.25A. My guess is that the original power supplies feed AC to a rectifier directly, and feeding it DC gives the same result without the rectifier having to do anything.

There’s also the issue of 14V vs 20V. Maybe the 14VAC ends up closer to 20VDC after being rectified; I’m not an expert on electronics but 20VDC seems to work. Sort of.

I also don’t know how many amps a rectified 14VAC at 4A becomes when it gets converted to DC

I just ordered a new batch of power supplies and this time they were 20VDC at 2A. I sent them back.

The Failure Mode

At best the printers I sell with 3.25A supplies tend to print lines that cover the full width of the label somewhat washed out. I always thought it was caused by a weak power supply, but it was never bad enough that I was motivated to try to figure it out.

Now, I have several printers that with the 3.25A supplies will print an inch or so of the label then die. The way it dies is that the printer stops, the light on the button goes out, and it makes a strange “burp” noise. The light on the button then comes back on and the printer is back to normal. The light going out momentarily suggests strongly that the printer overtaxed its power supply. It gets about an inch of label printed before this happens.

Failed Label

Another clue: with the 2A supplies it gets a quarter of an inch of label printed before dying the same way. Less current, less label.

I’ve had the same results with several printers and several power supplies. Something is going on.

Capacitors

Inside the printer are two big capacitors, 22000 uF if that means anything to you. The printers are all getting to be 20 years old, so it’s possible that the capacitors are failing. Capacitors store electricity and could be doing two things inside the printer: smoothing out the rectified AC, and building up a reserve of power for doing things like printing wide black lines.

Next Steps

I’ve ordered a 4.5A 20VDC supply to see if it works better. I’ve also ordered a couple of new capacitors, and I’m hoping that they will make the problem go away.

Update 1: I got the new capacitors today, installed them, and the printer still failed the same way. So it isn’t the capacitors. Oh well, I had hoped that would explain things.

Update 2: I tried printing with a bigger (4.74A instead of 3.25A) and the problem went away. So it sounds like this is indeed a power supply problem. But with the “solution” given in the next section, you (and I) can manage just fine with the smaller power supplies.

The Solution

A little careful searching led me to the solution. If you crank the darkness up to the maximum in the printer driver this failure will happen. I had recently tried turning up the darkness. So I backed it off to 12 or so and the problem went away.

The Jaggies

There is a setting in the driver for this printer that controls dithering. This is one of several techniques used to compensate for the low resolution of the printers by smoothing out edges. It’s useful if you are trying to print photographs or low-resolution graphics, but it causes print quality problems when printing labels. Unfortunately the default setting in the driver is for dithering to be on.

It can sometimes be hard to recognize labels with the jaggies. Often the sense is just that things don’t look as good as they should, or that some labels look better than others. The problem is especially acute if you’re trying to print a scanned label. Here is a label, printed with stamps.com software, that has the jaggies:

Label with jaggies

Look especially at the “XI” logo next to the return address. Once you start seeing the jaggies they are all over the place. Now compare the above label with this one, printed with dithering turned off:

Label with dithering turned off
Turning Off Dithering

If you think you have dithering turned on (it’s on by default) it’s easy to check the setting and change it. Get into Printer Preferences for the Zebra Eltron printer (there are many ways to do this, and they vary by which version of Windows you are using). There will be several tabs; pick the Graphics tab. Look for the Dithering section. One of the options will be selected; if the option None isn’t the one selected, select it. Then just pick OK and you’ll be done. Here’s a picture of the dithering settings:

Dithering setting turned off

Reloading Windows XP On Your Old Computer

This is a cautionary tale. Hopefully it will encourage you to not try to install a fresh copy of XP, or it will give some hints which will make an impossible project a little less impossible.

So I got an old XP computer given to me and I wanted to sell it on eBay so I had to wipe the hard drive. It didn’t have an OS recovery partition so I just found an old XP CD and reloaded it. That’s where the fun began.

I expected XP to just load and work. But I forgot that back in the XP days you had to load drivers for your computer (or motherboard) and all installed cards, for anything important, like a network card, to work. And of course I didn’t have any of the necessary drivers.

It took two days to find, download, and install the drivers I needed. To download the chipset drivers I had to pry the heatsink off the motherboard chipset chip to read the number off it. (I found out they make thermal compound in cement form for gluing such heatsinks back on.) For other drivers I started with the hardware ID found in Device Manager’s properties and did some serious searching. It also turned out that the Internet Archive (http://archive.org) has a lot of the old driver CDs that came with old motherboards — you don’t need to find the exact same one, if you’re lucky one for the same chipset will work.

At this point it is a good idea to activate Windows. It seems that the online activating service run by Microsoft no longer works, but the phone activating service still does work. It’s a giant PITA but just do it. Eventually the phone activation service will stop as well and we’ll all be stuck. Microsoft originally promised that they would release a patch that would eliminate the need for activation in such a case but I’m not holding my breath.

With the network card driver installed and Windows activated, I was able to start looking for updates through Windows Update. But it wouldn’t work, and Internet Explorer wouldn’t load pretty much any website. I figured out that the encryption certificates loaded with XP were all out of date, and nowadays almost all websites are https, none of which would load without current certificates.

After some fruitless searches for sources of current root certificates, I decided to try to get Windows Update working. I needed to load all available updates anyhow, and Windows Update was where certificates used to come from. That led me to discover that Microsoft has turned off Windows Update for XP, as well as most (or all) other unsupported operating systems. Last time I tried this, years after XP support ended, it still worked. No more.

More searching led me to a website in Germany, http://wsusonline.net. The owner of this site has built a tool for updating Windows computers’ Microsoft software without a network connection. A side benefit of this website is that it has access to old updates for no-longer-supported software like XP. [I don’t know if he has copies of old updates or if he just knows a way to download them from somewhere on Microsoft’s website.] In any case the website will get you the updates you need.

From wsusonline.net, you need to download an update-generating program, run it to generate a folder containing all the updates you want, move that folder to the computer you want to update, and run an included updating program. It sound involved and does take time, but it works. Follow these steps:

  1. On some other computer, download the update-generating program from http://download.wsusoffline.net. There are many versions covering different ranges of software. For XP you want Version 9.1. It’s the last version that supports XP.
  2. Unzip the resulting file and run the program UpdateGenerator.exe. Start by selecting the Legacy Products tab. That will get you into the section for XP updates. It all looks pretty complicated but just pick what you think you need. I suggest selecting all the Internet Explorer and .NET stuff too.
  3. Select the output medium. I tried creating an ISO file first but it didn’t work. So I tried outputting to a USB drive and that did work. I used an 8GB drive and it almost filled it up.
  4. Click Start to generate the updates on the USB drive. It will take a while. I don’t remember if it asks questions during the process but you’ll figure it out.
  5. Move the USB drive to the computer you want to update.
  6. Run the UpdateInstaller.exe program from the USB drive. It will run a long time, it will ask questions, and it will request that you reboot several times.
  7. Keep running UpdateInstaller.exe until it gives an unambiguous message that it has concluded successfully. It takes three or four restarts to be finished.

Now you have a running and updated copy of Windows XP running on your machine. Make an image backup of it (I recommend the Image series from http://terabyteunlimited.com), since you don’t know how long the procedures described here will continue to work.

There is still a problem with root certificates. The updates loaded with the above procedure didn’t get the certificates updated enough to work with today’s websites. I don’t know how to solve this. Maybe a different browser would supply its own certificates. I don’t have the time or patience to pursue this, but if you know an answer I’d be happy to hear about it.