Video Issues

timmeh87 · Post by **timmeh87** » Wed Mar 08, 2006 5:42 pm

neildo: dont "try" if you "find one lying around".. that part is reqired for proper operation! its in the datasheet. i hope youve read it.

but yeah. you need to put that cap there

Neildo_64 · Post by **Neildo_64** » Wed Mar 08, 2006 6:37 pm

I read the datasheet and I actually remember something about that, but I forgot at first, and it seems to work fine, but Ill see if I have one. If I dont I guess Ill have to get one at Radio Shack or just tear one from something else.

timmeh87 · Post by **timmeh87** » Wed Mar 08, 2006 6:44 pm

100 uF wouldnt be that hard to find. you can add up lower ones too if you are really cheap. like 47uF + 47uF ~ 100uF. in parallel.

or 47 + 25 + 19 + 7 + 2.

. no, dont do that.

Neildo_64 · Post by **Neildo_64** » Wed Mar 08, 2006 7:46 pm

or 47 + 25 + 19 + 7 + 2.

lol

Well, whaddayano, I checked my stash of electrical component junk, and I happen to have one. Brand new! (well, sort of. Never been used but been out of package in a clear container for 5-6 years.

)

I'll see if that fixes some of my video problems. If not, I guess I'll keep trying things.

G-force · Post by **G-force** » Wed Mar 08, 2006 8:40 pm

I'll be interested to see if it works after you try the cap. There are already a few capacitors on the N64's 3.3V line, so it might not make a difference.

Hey marshallh, I tried using 6 brand new D cells (alkaline). Would you believe I had the same problem as with the AA's. And after a minute the voltage still dropped! All the way to 6.9V (then the screen started wacking out)! And these are brand new, they were at 9V before I turned on the N64.

But guess what. I hooked the AV out up to another pocket TV to see if it looked the same as the PSone screen. NOPE!

It looked almost perfect wheras the PSone screen had huge grey lines going down the screen (and this was before the battery dropped, it still read 7.3V on the meter). There was a small bit of wavyness every now and then, but I could barely notice it at all. It might have been normal for all I know.

So...... I dunno. Feeling kind of screwed here.

Neildo_64 · Post by **Neildo_64** » Wed Mar 08, 2006 9:58 pm

I have no other portable screen to test on at the moment...but I bought a psone screen on ebay yesterday (cant wait to get that) so at the moment all I have is my intec pad screen. I do remember a while back when using it on my TV, it worked fine and then testing it on my screen, it was fdkljisnntmv. (<---that should be a new adjective) Maybe theres something about these LCDs that sucks

G-force · Post by **G-force** » Wed Mar 08, 2006 10:10 pm

Intec pad screen... That's a 2.3" screen with controller right? I had one similar, made by Hip Gear, and I had the distortion problem on it too (just like this portable with the PSone screen). I also had the problem where it looked good on the normal TV and crap on the LCD. At the time I just thought my N64 or screen was messed up since I did a ton of rewiring. Now I'm thinking it was something else.

Anyways, I doubt it's your screen.

Neildo_64 · Post by **Neildo_64** » Thu Mar 09, 2006 8:06 am

yeah, thats what I was getting at. I dont think its the screen. I had originally figured it was because of all the re-wiring I did, like you, but I think we have some sort of problem caused by the n64 being hooked to the screen. Its weird because it works fine on a TV and it doesnt on the LCDs, even if the LCD has a separate power supply.

G-force · Post by **G-force** » Thu Mar 09, 2006 9:09 am

Exactly. It makes no sense. I have one more idea, hook up the old N64 power supply and see if the problem persists. I'll do that this evening.

Neildo_64 · Post by **Neildo_64** » Thu Mar 09, 2006 2:32 pm

I just thought of something else. Maybe its the model of the n64 mobo we're using. This is my 3rd n64 (fried two before this) and neither one of the two before had the distortion.

Also, I desoldered the power plug so it would be a pain to hook up my original power supply. Tell me if that works will ya. Oh yeah and Good Luck.

Post by **marshallh** » Thu Mar 09, 2006 6:42 pm

Crap. I have the same exact problem. Lots of diagonal grey lines that gradually take over the entire view.
It gets worse as the regulator warms up...
I tried RGB and got the ghost of a signal, but apparently there's enough noise that it doesn't work at all.

I tried a 1000uf cap on the output of the 3.3v TI regulator, still the same.

It seems the 7805 on the mobo is just responsible for the video signal generation... hm...

I'll try a few more things soon.

Neildo_64 · Post by **Neildo_64** » Thu Mar 09, 2006 7:52 pm

maybe the 7805's get stupid after being used a lot. Maybe if we replace the 7805...or something...

Post by **Gamelver** » Thu Mar 09, 2006 8:15 pm

perhaps some adjustment to the 7805 circuit on the N64 is needed, then. a cap on the output, or perhaps some component is fried. Try doing a little troubleshooting from the 5V line on the N64

timmeh87 · Post by **timmeh87** » Thu Mar 09, 2006 8:22 pm

whats this about the 7805? did you remove it?

Post by **marshallh** » Thu Mar 09, 2006 8:29 pm

No, I doubt the 7805 has anything to do with it.

I've noticed something VERY interesting...
When I have the psone lcd just running on the same dvd player battery as the n64, I get a rolling white bar. This only happens when the N64 is turned on. Even though I don't have the video line connected at all!

This means there is some serious power supply problems going on. I have a 1000uf capacitor across the power inputs of the PSone lcd, but same result.

If I hook up the N64 running off a battery to ANOTHER psone lcd that is running on wall power, the picture is just fine.

So, the problem is noise being introduced by the TI DC-DC converter. I have caps where it says to have them, yet no dice...