Matrix Orbital Corp

I'm having some problems with my VFD (VK204-25) installed in my HTPC.

Occasionally, after several hours (sometimes days) of running, the display will just go blank, almost like the light source was turned off or something. LCDC still recognizes the display, but nothing is shown on the screen. I normally have to reboot (shut down the PC, and then power it back up) in order to fix the problem.

Also, it seems that my start-up screen which is saved to the EEPROM is getting crupt somehow. I save the start-up screen, while inside of LCDC, and everything seems to work fine (even after a restart). But the last couple of times I've had to reboot, I end up getting a bunch of garbled text showing for the start-up screen, which I then have to reload inside of LCDC.

I'm not sure this is related, but thought I'd provide this background.

When setting up my HTPC initially, I had some problems with a Griffin PowerMate not working (not being detected by Windows) correctly. Sometimes I would startup the computer, and find the PowerMate (PM) working, other times, it would not be. I figured it was during some software installation problems, so I kept going back to a "known good state," and then watching between every software install. Well, I got all the software installed the last time, and it was still working. Then, all of a sudden, it stopped again.

Here's what I determined.

I'm using 3 USB devices in my HTPC (all internal USB cables), a Griffin PowerMate, Matrix Orbital VFD, and a USB-UIRT. I had all three of these cables bundled together with cable ties to keep the installation neat. I realized that sometimes if I unplugged the PowerMate, and moved the cables around, it would start working again, so I assumed it must be a loose connection on the USB header. Actually, it turned out to be that the PM didn't like it's cable being bundled together with the VFD's cable. I cut the cable tie, and routed the PM's cable a different route, and bundled it with the USB-UIRT's USB cable. This has stopped the PM problem from happening again.

What I'm wondering, is if there was a noise problem with respect to the VFD's cable or something. Since the PM works bundled with the USB-UIRT's USB cable, I can only assume that either the VFD's USB cable or the VFD itself (the PM's USB cable was bundled right under the VFD before), had something to do with the PM not working. I wonder if maybe the internal USB cable supplied with my VFD is intermittent?

I've also noticed that I see some phantom lines on my display sometimes, almost like it wrote something to a line, but then corrected it with the next update of that particular screen. This is especially noticed when using a spectrum analyzer with WinAmp. Sometimes I'll see some text in the bar graph.

Sorry for the novel, but I just thought I'd provide as much information as possible. Oh, I'm also using 3 Dallas 1-Wire probes, and am controlling 1 92mm fan. I have the unmodified floppy connector connected to the VFD as well.

hi geogecko,

After looking at your post, I suspect the problem to be electrical noise going to the unit via the internal usb cable. You may want to test out the unit with an external usb cable because it has better noise protection than an internal usb cable. If the cable is the case, you may want to try is to pierce the shielding part of the internal usb cable and attach it on your case. This will get rid of a lot of noise for you.

Let me know how it turns out.

Best Regards,

Tom.

Thank you very much for your input. I was beginning to think the same thing, since the internal USB cable does not really have a ground to anything, even the motherboard. I will try it out with an external cable, and see if the problem goes away.

If that seems to fix the problem, I will either consider leaving that cable installed, since I have an access panel on the back of the case, or may consider soldering a short wire to the shielding on the internal USB cable (near the motherboard), and attaching a small ring terminal to it, and then removing one of the motherboard screws, and placing the ring under that screw.

Thank you for your suggestions. Hopefully, in the next week (maybe weekend), I'll be able to test these things out.

Tom.

I installed an external USB cable, and disconnected the internal USB cable from the VFD. (Interesting that a USB connector is roughly the same width as an Ethernet port...when you're fumbling around on the back of a case, with only a few inches to work with...well, let's just say it took me a few minutes to realize what I had done...)

Anyway. I saved the start-up screen to the EEPROM again, and saved everything, and shut the computer down. I then went in and turned the PC back on, to find that my start-up screen was there, but still had 5-6 strange characters in one place on the screen. I will do some more testing this week, and see if there is any improvement at all. So far, the VFD has not turned itself off yet, so that is a good sign.

I am however, still seeing some "phantom" characters once in a while, but this may be normal, using LCDC software.

I will let you know how the testing goes. Let me know if you have any more suggestions. Oh, and by the way, this external USB cable has two ferrite beads at the ends of each side of the connector.

Jason.

The random characters might be something LCDC is sending down the line. You can monitor the port with somekind of monitoring program to see if that is the case.

Let me know with your continued test.

Best Regards,

Tom.

Well, the display was off again when I arrived home today. Not sure what is causing that.

I rebooted the computer (complete shut down, pause, then turned it back on), and the start-up screen was even more corrupt this time than it was just after I had saved it yesterday.

I'm don't know much about port monitoring software. Would I be able to tell what is causing the random characters. Maybe I should just do a reinstall of LCDC, and see if that helps. I'm out of ideas after that point.

Thanks.
Jason.

What is the PCB revision of the VFD? It should say rev 1.0 or 1.1.

Tom wrote:What is the PCB revision of the VFD? It should say rev 1.0 or 1.1.

Tom, if you would, can you point me to the location on the PCB where it would be? I'm at work right now, but I can check when I get home.

Thanks.

The revision will be located at the top of the PCB side. Your USB cable might be covering it. Somewhere along the lines

You were right, the USB cable was covering over the information.

Mine said Revision 1.0.

Right now, it's got a flashing square at the top left character, and has "phantom" squares all over the display at random times. This was before I unplugged the USB cable to check the PCB revision. It's like every day, it just gets worse, unless I do a reboot. I still have the external USB cable hooked up to it.

Jason,

Can you email me at support@matrixorbital.ca ,so I can set up a RMA for you. Please include your first, last name, shipping information, and phone number.

Best Regards,

Tom.

I've been waiting to contact you for some time now, as I've been testing the display that was repaired a few weeks ago. (The rear microcontroller board was replaced with the current version.)

First and foremost, thank you for the quick turn-around in replacing the board. I was very impressed with your shipping speed, as I didn't know it was possible to ship from Canada to the US in one day!

Unfortunately, I am having similar problems as before.

After about 6-7 days of running continuously, with no problems what so ever, I woke up one morning to find that the display was flickering odd characters and also had the flashing cursor again. I have not had the display turn itself off again since the repair, but am still having these issues.

I turned off all events inside of LCDC, and just used 2-3 different screens. I turned the computer off again, about a week ago, to reset the display, and powered it back up for a week, while out of town, and upon return, had the same results.

It appears that someone else is experiencing the same issue, over at the LCDC forums. I started a thread over there, after I got the display back, as I thought it must be related to LCDC, and not the display.

Do you have any further input to this problem?

Thank you very much.

Jason,

I have read the post on LCDC, and it looks like LCDC can be a possibility. Can you try reinstalling LCDC?

Tom.

Will do. I should be able to do that tonight, but it may take a few days to be sure that a reinstall of LCDC has fixed the problem, as before, it took 6 or 7 days before I saw the problem again.

Thanks again for your great customer service.

Jason.

Jason,

I may want to add in to try removing all your other drivers to see what other drivers may be conflicting with the MO drivers.

Best Regards,