Video Issues

Neildo_64 · Post by **Neildo_64** » Mon Mar 06, 2006 10:04 pm

I was just wondering if an inconsistant voltage was going to the 3.3 line on the n64, would it possibly cause video distortion?

I ask this because I am using a TI converter and for some reason, my screen sometimes gets diagnol lines or vertical waves and distorts the picture a bit.

The input lines to the screen are fine and so is the power supply to the screen (it's an Intec pad screen). even when the screen is getting 10.5-11.5 volts, it sometimes does it. After running it for a while (5-10 mins) usually the distortion goes away.

What might cause this?

Post by **marshallh** » Mon Mar 06, 2006 10:11 pm

Do you have the filtering capacitor on the output of the converter? That's probably the reason.

G-force · Post by **G-force** » Mon Mar 06, 2006 10:11 pm

I have that EXACT same problem. Even the going away after a few minutes part. I'm sorry to hear you're having trouble, but I'm glad it's not just me.

I tested the ouput of the converter and even when the lines were appearing, it had a perfect 3.3V output. I do have a digital meter though, so small spikes might not show up...

I have no idea why this is happening either, but it's driving me up the wall. My entire portable is complete except this small (or rather large problem really, since even a small problem is a big problem on a portable) problem.

Neildo_64 · Post by **Neildo_64** » Mon Mar 06, 2006 10:53 pm

G-Force, I know what you mean. Its like a very small bug in a huge game or program. I hate that. I also have a digital multimeter so I cant check it any better than you.

but mine had a constant 3.3V too.

And no I dont have a filtering capacitor.

G-Force, if you figure it out, would you PM me or something. I'll tell you if I fix mine. Who knows, maybe two heads are better than one and we can fix it if we both work on it.

timmeh87 · Post by **timmeh87** » Tue Mar 07, 2006 3:29 pm

you guys need an oscilloscope.

Post by **Gamelver** » Tue Mar 07, 2006 4:28 pm

decent ones can cost a bit of money, though

......definitely useful, though

.

and you could make your own, too, I think. Hard, but possible.

timmeh87 · Post by **timmeh87** » Tue Mar 07, 2006 5:08 pm

the solarcar team is getting a 4 channel digital scope soon. *excitement*.

Dr.Weasel · Post by **Dr.Weasel** » Tue Mar 07, 2006 11:33 pm

My physics teacher is trying to get me to shell out the extra money and get one with oscil. capablities. Are they worth it and what ones would you suggest?.
Sorry for the hijack, it would probably be better if tim or somebody who knows pm'd me the answers. Thanks
-Hayden

Neildo_64 · Post by **Neildo_64** » Wed Mar 08, 2006 4:44 pm

Oh dont worry about hijacking.

Im also curious and I'll probably just have to find the solution to my problem. Maybe G-Force will first.

I hope so, cuz Im tired of messing with it...

G-force · Post by **G-force** » Wed Mar 08, 2006 4:59 pm

Did you try the electrolytic 100 uf capacitor on the output ? It's needed for the converter to work correctly. look at the PDF for it.

I have no idea whats wrong with mine though!!! I tried everything! Separate batterys for the screen and N64, 3 different batterys for the N64, different output caps... Everything!
I had to stop before I threw it through a wall. (I have carboard room separators.)

timmeh87 · Post by **timmeh87** » Wed Mar 08, 2006 5:13 pm

maybe the converter is bad?

scopes: these things are mother f**** expensive! you can pick up a used analog one (with the green line on the CRT) for like 200 bucks probably. its ok for some basic troubleshooting, but its no good for like advanced analysis of crap. basically because you cant pause it, and it dosent do any calculations of anything for you - its just a wavy green line. signal or no signal. thats about it.

to be honest, i have only used analog scopes, and i have only used them by trial-and-error. no one ever taught me how to use one. but its not really that hard.

anyways, the digital one we are getting cost over $2000 canadian. from what i understand, you can pause screenfuls of data, save data, it has a colour lcd display, and in general everything about it is "digital". theres probably onscreen menus and stuff too. it can probably calculate averages of things and automatically pick proper "zoom" levels.

a better person to ask would be codeman, i get the feeling hes used a scope or two in his life.

if youre looking at buying one, you will probably be getting a used analog one. look for ones with two or more channels, it might come in handy. thats about as far as i can guide you...

G-force · Post by **G-force** » Wed Mar 08, 2006 5:19 pm

I tried three different ones

Post by **marshallh** » Wed Mar 08, 2006 5:22 pm

G-force, what kind of batteries are you using? I had this problem when I used AA batteries. I'm running my new N64 off of a DVD player battery and no problems yet.
I don't think AAs can handle the current draw very well, so their voltage is dropping and you get the signal distortion.

Neildo_64 · Post by **Neildo_64** » Wed Mar 08, 2006 5:24 pm

G-Force: No I havent tried the capacitor on the output. I guess If I have one laying around I might try that. I have also tried the separate batteries and what not...Its really annoying because its not something serious (like the screen just not coming on) its one of those little things that is just so annoying.

marshallh: That was also something I was thinking. Maybe something with more amps would help. My original question was sort of along those lines. I was wondering if the converter had anything to do with running the video to see if maybe it couldnt handle the load. My N64 is running on 8 AA batteries. so 9.6V at 2500mAh. I have a couple big 12v batteries I could test it with. I'll try that later and if it fixes it, that would be awesomez except I would have to find a new power supply.

G-force · Post by **G-force** » Wed Mar 08, 2006 5:34 pm

So if AA's are too weak, maybe I should try some C or D cell batterys? That sounds worth a try.

Here is all I've tried so far.
The first set was 2000 mah Ni-Mh AA's
Second set was 2700 mah N-Mh AA's
Third was alkaline AA's
Fourth try was a big honkin lead acid 12V battery from an air pump. It acted the same as the AA's only I didn't bother to test for a voltage drop. I suppose I ought to check that.

All the AA's had about a 1-2 voltage drop, which was odd because I had run the N64 off them before and it ran fine with no lines on the screen.

The screen was running off a seperate 7.2V ni-mh battery for testing, so it wasn't adding to the N64 current draw. And the screen looked fine using video from my DC, so it's not the problem. Although it does seem to show up the distortion a lot more than my 4" pocket TV does, which confuses me a bit.