Can I recycle my VK202-25?

trode · Post by **trode** » Fri Jun 04, 2004 10:59 pm

Hello all.

A few years back I picked up a VK202-25 and the matching mounting bracket with keypad for your typical car mp3 project.

After I retired the unit, I left it for later use. Now that I want to utilize it again, the unit no longer powers up. I mean that I do not see the Matrix Orbital text appear when power is applied as it used to do. I tried reseting the baud rate. no success.

I know I haven't crossed the power nor has anything chipped or burned anywhere.

I checked to make sure the voltage regulator if functioning and it does. I checked the pin voltages. They're fine.
Does the Vacuum display corrode over time or deteriorate?

In any case, I think the controller is more than likely functioning and the VFD display itself is dead.

So what I was wondering is,
Can I salvage the controller board? Can I hook it up to a basic LCD display rather than another VFD? Or is the existing VFD and controller not 44780 compatible?

One more thing. Is there a diagnostic document available? So I can check more than the basic pin outs? Such as logic levels on the PIC, voltages on the VFD pins, etc..?

I look forward to any help or guidance.

Regards,
Trode

I

Post by **Mat-Moo** » Sat Jun 05, 2004 4:56 pm

Have you tried connecting it up, and sending text to it? Typically VFD's are blank until you send something to them, no "Welcome" screen as such.

trode · Post by **trode** » Sat Jun 05, 2004 9:25 pm

No Welcome screen? Wait a minute. I could swear there was. Maybe the Cajun mp3 player script did it? Hmm. I'll give it a shot.

I'll let you know.

trode · Post by **trode** » Sat Jun 05, 2004 9:47 pm

Nope. Nothing at all.

Note: the serial cable works find on my other lcds. But they aren't from MO.

Miles · Post by **Miles** » Mon Jun 07, 2004 9:28 am

Hello...

The unit you are describing, is it a "wide voltage" module (7-15Volts) or our standard 5 Volt module??

trode · Post by **trode** » Mon Jun 07, 2004 10:16 pm

I believe I purchased the wide voltage. To be safe, I applied 5v with no luck. I then use a Radio Shack, variable voltage power adapter and and tried 6v, 7.5v, and 9v (300mA).

My VFD has no marking of any kind confirming the wide voltage. Is there a way I can tell? Because I am almost sure I bought the wide voltage version and then I spotted the 5v regulator on the circuit board and felt more likely correct about my recollection.

Post by **Henry** » Tue Jun 08, 2004 1:52 am

Best and easiest way is to take a picture of the back of the unit and post it on the forum or e-mail Miles at myero@matrixorbital.ca with it.

trode · Post by **trode** » Tue Jun 08, 2004 9:59 pm

Good Idea. Here it is. Please excuse my camera's poor image quality.
Note: The Diode and the Voltage regulator are not showing burnt marks. Thats just flux that was never removed from the factory.

Post by **Henry** » Tue Jun 08, 2004 11:17 pm

Since this is a VFD, your power supply might not be enough at 300mA, I would recomend trying a higher rated one, as well as it is a Wide Voltage unit, so put in 9 to 15 V. The flux is OK being there and would not create any problems.

trode · Post by **trode** » Wed Jun 09, 2004 9:15 pm

Yes, I know the flux is not a problem.

I applied 12V @ 1A. Nothing. I also tried it in a test bench pc I have (with the proper wiring of course).
How much current do it need? I didn't think it required that much more. I don't recall having power issues in the past.
Any other tips? I appreciate everyone's efforts thus far.

I was initially asking to utilize the controller but these attempts to get it working has brought me some hope. If only I can see the light...the VF lights, that is.

I was just thinking...
Could I replace the VFD with a Noritake CU20025ECPB-U1J model?

Miles · Post by **Miles** » Thu Jun 10, 2004 3:28 pm

Before you go ahead and try that, we can do a "little" test to see if the display actually works...

If you flip the display over and in one of the corners you will notice a white connector (labeled "C2") with three pins...this is an internal test header to test the functionality of the display's drivers...If your looking at the display with the white connector facing the top, the following pinout from left to right, is as follows:

+5Volts, Ground, Ground

If you can rig this up and let me know if the display comes alive, this will help!!

trode · Post by **trode** » Thu Jun 10, 2004 7:59 pm

No lights.

I used a 5v @2A power adapter to make sure I had more than enough current available.
I was able to make a reliable connection to the white connector. No lights. I also ran the 5V source on each of the 4 corners of the display (each group of 3 pins) while keeping the ground connected to the 2 right pins of the white connector. By following the traces and confirming it with a continuity test, I tried the 4 corners as a secondary test.

I'm lov'n the help and support....Keep 'em coming.

Miles · Post by **Miles** » Fri Jun 11, 2004 10:10 am

Interesting...you should of received a default test pattern...now back to the PCB!!

Can you confirm that the output pin of the volage regulator is indeed 5 Volts? One other measurement...can you measure the voltage, with reference to ground, each side of the crystal (oscillator)?

trode · Post by **trode** » Fri Jun 11, 2004 9:49 pm

Following your request I measured the voltages of each side of the crystal.
Facing the controller board with the power connector to the bottom left and the DB9 pin to the bottom right: The left side of the crystal measures 2.342V. The right side measures 2.144V. As I measure the regulator once more, I get a perfect 5.000V reading. That is one hell of an accurate voltage regulator. Either I got really lucky or you guys are serious with your source of components for production.

Miles · Post by **Miles** » Mon Jun 14, 2004 10:41 am

From the information you provided me, it appears that the display itself is faulty. If you wanted to send it back to me, all I would charge you for is the cost of the display, a very small repair fee and shipping. You can email me at myero@matrixorbital.ca