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Noritake GU128x32-311
http://forum.lcdinfo.com/viewtopic.php?f=14&t=697
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Author:  coorz [ Sun Sep 19, 2004 21:25 ]
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Sorry to hear about your VFD Robin :cry: . Hope it'll turn out ok. You might salvage those fuses from other defective equipment you have left over.

Author:  Lord Kano [ Tue Sep 21, 2004 7:43 ]
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cpuwiz wrote:
Based on what you've described, I'd say you blew the fuse. I didn't even know it was blown for quite awhile and was pulling my hair out trying to figure out what was wrong. I went over all my cabling several times until I finally noticed the fuse and tested for power across it. I got +5v on side, 0v on the other.

Here's a pic of the back of my unit. It's mounted in an HTPC that I'm building, so pardon the angle.

http://izzywizzy.org/images/IMG_2745.jpg

And a closeup of the new fuse:

http://izzywizzy.org/images/IMG_2742.jpg

It's a Littelfuse 2A SMT fast-acting fuse. I actually ordered this from Digikey:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=214079&Site=US&Cat=31916779

'cause I wanted the fuse block to make it easy to replace a blown fuse in the future. Unfortunately, the fuse block was too wide and just wouldn't squeeze in there between the IC, capacitor and power connector. I ended up just soldering it directly, though it was a bit tricky to get my soldering iron in there on the left side.

The fuse by itself is this:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=219381&Site=US&Cat=31916779

Just for grins, here is a comparison of the old fuse to the new one. The blown one is on the bottom:

http://izzywizzy.org/images/IMG_2749.jpg



Wiz, to your knowledge is there more than one fuse?

I had my vfd working fine. I was testing out a new cable for it and decided to try the self test. When I connected the power I saw a small spark between pin 2 and pin 3 of the power connector, after that the unit would not respond to either the self test or data sent with a known good cable.

I broke out the volt meter and I get 5 volts on one side of the fuse and 0 on the other. The "inner" side of the fuse has 5v. The side closer to the edge of the board has nothing.

I thought that before I go about soldering on the board I should try bypassing the fuse. I bypassed the fuse with a small piece of copper wire. Still no go. No self test and no image using a parallel cable.

I don't see any other obvious fuses, but I could just be missing it.

Author:  cpuwiz [ Tue Sep 21, 2004 8:33 ]
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To my knowledge, that's the only fuse. The fact that you only have 5v on one side is a good indication that it's blown.

Do you have any idea what caused the spark? How is your power cable wired? Where is that power from, the PSU? My power cable is a custom, half of a split 4pin molex with a 3pin molex connector; only black and red are wired, the middle is empty.

It won't hurt to replace the fuse, so I'd do it. You're risking more serious damage with the copper wire, but you probably already know that.

Author:  cpuwiz [ Tue Sep 28, 2004 20:56 ]
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Now I'm having problems with my fuses and wonder if Henri or coorz have any thoughts?

Basically, if I have the VFD hooked up when I power-on the computer, the fuse will blow. I've tried both quick and slo-blo 2A fuses. If I wait until after the PC is on and then plug in the power, all is well. I figure it might be the PSU, but I don't want to invest in another just to have the same thing happen.

I thought about wiring in some sort of manual switch, but since this will be in an HTPC, that's not really an option. I also thought about some sort of time delay circuit that would kick in a few seconds after the PSU has powered, but I can't find an adequate circuit and I'm still somewhat of an electronics noob, so modifying the ones I've found is a bit over my head.

I'm thinking there might be some solution with the UIRT2 I've built and Girder, but I haven't looked into that yet.

Thoughts?

Author:  coorz [ Tue Sep 28, 2004 21:06 ]
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Well i have noticed with the 311 that one should never power it on when your PC is on. When i do that, my PSU shorts out for a split second.
Perhaps because it has a relatively high power requirement.

Author:  robthebob [ Tue Sep 28, 2004 22:24 ]
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I just resoldered my fuse today, and the VFD works on the test mode perfectly. It also doesn't mind being plugged in while the pc is on - I do have a quite high-specced PSU, so I don't know if that's it.

Author:  cpuwiz [ Tue Sep 28, 2004 23:23 ]
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So what do you think my options are? Invest in a better PSU? This one is an Antec PP-303XP 300W. Pretty good specs, but ...

The 311 seems to be getting more current at power-up than that fuse is able to accept, but only when the PSU is powered-up at the same time. I suppose a better PSU could fix it, but I don't know what specs I'd need to know that and make it worth the investment. I'd rather take that money and invest in a Noritake 800 if it comes to that.

I'm pretty sure a time delay circuit would solve my problem. I'm just not sure how to build it.

Author:  robthebob [ Wed Sep 29, 2004 0:48 ]
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We did some time delay circuits in a recent electronics project - I'll see if I can find my diagrams for you.

Author:  Lord Kano [ Wed Sep 29, 2004 9:07 ]
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cpuwiz wrote:
So what do you think my options are? Invest in a better PSU? This one is an Antec PP-303XP 300W. Pretty good specs, but ...

The 311 seems to be getting more current at power-up than that fuse is able to accept, but only when the PSU is powered-up at the same time. I suppose a better PSU could fix it, but I don't know what specs I'd need to know that and make it worth the investment. I'd rather take that money and invest in a Noritake 800 if it comes to that.

I'm pretty sure a time delay circuit would solve my problem. I'm just not sure how to build it.


How much of a delay do you think you need? It would be cheap and easy to use a relay for a brief delay. But the delay will be very brief.

[/u]

Author:  cpuwiz [ Wed Sep 29, 2004 9:54 ]
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I wouldn't imagine anymore than a couple of seconds. Just enough to get past the initial surge and let the PSU settle. A relay is what I had in mind, I'm just not sure how to do it.

rob: That would be great...I'd really appreciate it.

Author:  robthebob [ Wed Sep 29, 2004 18:24 ]
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This is what we used in our project:

Image

The idea is that when the switch is depressed, it holds the top connection to ground, and the capacitor takes a while to recharge. I'm not sure of the values of the components in the circuit, but the capacitor we used was only about 10uF I think.

The delay depends on the time constant RC (i.e. resistance * capacitance) and it takes about 3*RC s for the capacitor to charge fully. In that case something like 100kOhms and 100uF would give you a delay on the order of 10s of seconds.

A quick google revealed this page that might help you:

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.htm

Author:  cpuwiz [ Wed Sep 29, 2004 20:20 ]
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Rob: Cool, thanks. I think I actually get the circuit and based on my calculations, a 47uF cap would drop the time to around 5 secs and I have a few of those lying around.

So I could replace the switch with a relay? A transistor? I guess I'm still not sure how to build the circuit so that there is no power to the VFD for those five seconds. How do I establish "when the switch is depressed", if it's with a relay?

Thanks for your help. I'm learning.

Author:  robthebob [ Wed Sep 29, 2004 20:28 ]
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Well what I was thinking was to effectively link up that switch to your power switch with a single-pole double-throw switch.

Using this circuit it wont cut power completely to the VFD, or at least it will initially and it will climb using an exponential curve to 5V over time approx 3*RC

Author:  mbates14 [ Sat Jun 24, 2006 16:58 ]
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the more that I thought about it, there was probably a reason why magellan dumped those VFDs to SBR partners.


that could be one.

Author:  n2hyo [ Mon Sep 04, 2006 4:02 ]
Post subject:  Pulling my hair out.

Well i got me a 311 all wired up and like others it does not display anything from the pc. I have checked and rechecked the wiring many times, i see the wires glowing orange, and if i put the display in test mode that functions and runs through the test screens fine. I have also tried various parallel port settings in bios with nothing showing when i run the noritake311_test program. So what do you think have i fried the controller on the display or is there something other i can try?

I may have removed the 5v supply while the display was connected to the parallel port which i now see does not go well with this display. I'm not so sure i want to buy another if they are so senstive.

Oh well, Thanks in advance

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