Portable NES Screen Flickering, Please Help

gwayland · Post by **gwayland** » Tue Feb 13, 2007 10:58 pm

I just (almost) finished my first portable, a NES. The only problem is, when I power it up the display flickers. No color change, only distortion. It also affects the volume and brightness display (the green bars). It only occurs when I have it hooked up to the video amp circuit. When I remove lead from the video out to the display, it goes away. Also, I have no audio at all. I am using the model from the book and followed it exactly. If anyone has any ideas, please help. I would appreciate it. Thanks.

Rellizate · Post by **Rellizate** » Wed Feb 14, 2007 5:03 am

For the audio, did you bridge the headphone pins on the psone screen?

Website · Post by **Life of Brian** » Wed Feb 14, 2007 10:38 am

What power supply are you using?

Retromaster · Post by **Retromaster** » Wed Feb 14, 2007 12:44 pm

it might be a cartridge read problem. you may need a new 72- pin connector. its what I did.

gwayland · Post by **gwayland** » Wed Feb 14, 2007 1:30 pm

OK, I figured it out, Retromaster was right. I replaced the cartridge connector (I did that last night, even though I cleaned the old one very well) That fixed that. Now then, the audio is perfect but the video is scrambled. Some is correct as I can see some of the text, but other parts are missing. The display is good, and I checked each resistor before I put it into the circuit for the video amp. I have triple checked the layout, and all is good. Would a bad transistor cause this, or is my NES screwed? Also, I have no cold joints and even resoldered a couple just to make sure, followed by a resistance test on all ground leads and any others that I could find to test. If you have any ideas, I would like to hear them. Thanks for the help so far!

Retromaster · Post by **Retromaster** » Wed Feb 14, 2007 1:36 pm

you used a 2n4401 transistor, right? it could be wired wrong or no +5 volts is getting to it, or it is dead. try replacing it and rewiring it. transistors can die easily. my nesp never worked.

EDIT: did your video amplification circuit check out ok?

Rekarp · Post by **Rekarp** » Wed Feb 14, 2007 2:09 pm

does it look like this?

My problem was that a resistor was bad and overamping the video feed.

I would suspect that something is screwy with your transistor not your NES. However try cleaning a Cart's connections and then retry it, it could be as simple as a dirty game.

Also, make sure your screen is getting atleast 7.2-7.4 Volts. Your battery may be dead. When my NESp gets low on charge the screen starts to flicker and the colors go a little strange.

Rototiller · Post by **Rototiller** » Wed Feb 14, 2007 3:36 pm

[/spam]
Well, heh heh, looks like that scene from the ring.

SEVEN DAYS (NOT INCLUDING NATIONAL HOLIDAYS)!

[/spam]

Retromaster · Post by **Retromaster** » Wed Feb 14, 2007 4:01 pm

it does.

"your gonna die in seven days!"
"OMG!! i'm gonna die next monday!!?"
"yes...wait...no, you're thinking buiseness days. just seven days from today."
"well, theres a holiday coming up, do I get the holiday?"
"depends. what holiday?"
"****** ****** **** day."
"then no."
"why not? everyone else at work is taking the day off!!!"
"look lady, i'm giving you 7 freaking days! I could just come up and kill the **** out of you if you want that instead!!!"

lol.
check your video amp circuit. that has to be a factor.

(that was from scary movie 3, FYI....)

jeroen · Post by **jeroen** » Wed Feb 14, 2007 4:04 pm

[spam] Euhm....hello? Ya is this the little girl? No euhm she isn't here right now. Can I leave you a message? Ya. Ok your ok gonna ok die ok in ok seven m'kay days[\spam]

jedi knight · Post by **jedi knight** » Wed Feb 14, 2007 4:44 pm

Make sure that your lcd's ribbon cable is connected. It might be loose which will cause the scrambled video.

gwayland · Post by **gwayland** » Wed Feb 14, 2007 5:02 pm

OK, the power is good. I am getting ~4.8V or so. The circuit is 100% bueno, i have now quintuple checked it. Also, the ribbon cable is connected well. It doesn't look like the picture. It is partly right, but partly wrong. Odd, I know. Any more ideas? Also, I think my first project was not too good looking, but I learned a lot from it. I think I will try a new transistor. That seems to be the only thing that I can think of, as well. I didn't know that they were that fragile. I don't think I cooked it (15W iron), but who knows. Thanks!

Rekarp · Post by **Rekarp** » Wed Feb 14, 2007 5:16 pm

gwayland wrote:OK, the power is good. I am getting ~4.8V or so. The circuit is 100% bueno, i have now quintuple checked it. Also, the ribbon cable is connected well. It doesn't look like the picture. It is partly right, but partly wrong. Odd, I know. Any more ideas? Also, I think my first project was not too good looking, but I learned a lot from it. I think I will try a new transistor. That seems to be the only thing that I can think of, as well. I didn't know that they were that fragile. I don't think I cooked it (15W iron), but who knows. Thanks!

What about the voltage to the screen? The NES should get ~5V and the PSone screen should get ~7.2V (I have mine 7.4V tho). I used my clunky 45 Watt iron so im pretty sure you didn't fry yours but it could just be bad.

One question tho. Are you powering the NES and the Screen from the same battery?

Also, check Here to see the corrections for the NES Handbuilt Portable.

If you can take a picture of the image it would help.

gwayland · Post by **gwayland** » Wed Feb 14, 2007 6:16 pm

OK, guess what? Somehow, I guess I messed up the board. I resoldered the old amp & outputs,ran it to a TV and got the same. Also, I forgot to mention that I got the audio working (a new connector solves 99% of problems, it seems). OK, now that I am not doubting my soldering skills, anyone have any ideas on where to look for problems? The board is a little scuffed, but no broken traces or anything that I can see. If someone has any ideas on where to look, I would like to know. Thanks!