Wavy Lines on NES-001 - but there's something more to it...

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

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lidnariq
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by lidnariq »

Bridger wrote:So, you're saying literally touch the axial capacitor to the circuit board while it's running? I hope that's not dangerous. :P
No, not while it's running. Just clip it in and see how the NES runs while you're going. Ideal places to add it would include "across the PPU" or "across the PPU's bypass capacitor". Here's a picture:
ppu_power_ground_marked.jpg
ppu_power_ground_marked.jpg (18.97 KiB) Viewed 12933 times
tepples wrote:beating between 60 and 60.1 Hz.
Ok, that's pretty clearly power supply crappiness.
nestendo
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by nestendo »

Well there's more than one capacitor in there.

If any of them are doing a shitty job of filtering power (that's their job, and they retire at age 15) then that will be making it through to the video signal. Nobody replaces one capacitor and calls it quits. I wouldn't really expect replacing one capacitor would make a difference to be honest. Would you replace one spark plug in your car? Btw I think if there's any capacitors I've NOT replaced, it's the big ones. They seem to hang in there longer and I don't usually have them on hand. All the little ones have to go.

I think that's what 3gen is talking about here. Until you replace them all there's not much point in looking deeper.

edit: This assumes your power supply is putting out nice, clean power. New capacitors won't fix a terrible power supply.
Bridger
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by Bridger »

Fair enough. As I've mentioned many times in this thread, I'm relatively new at this level of repair work. I've replaced the pin-connectors before, that's it. As far as capacitors and modulators and circuit boards and so on go, I'm very inexperienced beyond what I've picked up as I've investigated this problem. Since it was suggested that the main 2200 cap tends to be the culprit, I started there.

I'll search around online and see if I can find a pack that has all the new caps in it for an NES. Being in Canada, it seems that you can only get stuff like this online, anyway. ;)
Ok, that's pretty clearly power supply crappiness.
I think we can safely rule out the power adapter itself because using a Genesis one didn't change anything... unless using a bad power adapter can damage the NES?
lidnariq
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by lidnariq »

Nah, switching between different unregulated power supplies won't change things much.

An obvious workaround (although it's suboptimal for other reasons) is to use a newer-style switching DC power supply of 7-10V or so. They won't emit any 120Hz (from the NES's AC transformer and full-wave rectifier) and so should make the waves invisible (because the switching frequency will be in range of 10s to 100s of kilohertz)
CLChambers00
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by CLChambers00 »

I had an NES that only gave a grey screen and in the process of trouble shooting I decided to just recap the RF module. I used the right type and everything, got them from Game-Tech website. Before I did the recap I had a solid grey screen but afterward I now see these waves as pictured and discussed in this thread. Could it be a bad capacitor? This was my first soldering job so maybe I did not have strong connections or cross connections? What could I try to fix this issue given that I actually created it as explained?
lidnariq
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by lidnariq »

Check for cold solder joints—they have a higher resistance than well-flowed ones. If you're using lead-free solder they're easier to create.
CLChambers00
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by CLChambers00 »

To clarify... lead-free solder is easy to get well-flowed solder joints? So you recommend that I use lead-free?
lidnariq
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by lidnariq »

Er, no. It's easier to create a cold solder joint when using lead-free solder.

Not dramatically so, though.
roadkill908
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by roadkill908 »

Have you tried replacing the voltage regulator? I had the same issue with a Super Nintendo. I bought a new, high rated 2 amp 7805 from console5.com and when I soldered it in place it made the video crystal clear. I also recapped it first, but the problem wasn't solved until I had put a new voltage regulator after putting all new caps.
Kanbei85
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by Kanbei85 »

I am experiencing the same exact problem with my NES-001. My toploader does not experience this problem at all.
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Fisher
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by Fisher »

It may or may not help, but some time ago I had a similar problem with a Mega Drive.
It had only slight walking bars, but had a terrible noise of circa 60hz in the sound.
I tried lots of things, but in the end it was the power switch that somehow has inducting that noise.
Maybe you could try a different power switch and see if it helps.
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tokumaru
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Re: Wavy Lines on NES-001 - but there's something more to it

Post by tokumaru »

Power switch or power supply?
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Fisher
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Re: Wavy Lines on NES-001 - but there's something more to it...

Post by Fisher »

Sorry, I only saw this now, after over a year. :oops:
It was the on/off switch.
I think it sounds better and avoid confusion. :-D
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Controllerhead
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Re: Wavy Lines on NES-001 - but there's something more to it...

Post by Controllerhead »

Ok, so, my poor '07 Toaster died a few days ago =( No gray screen on boot, nothing but a tiny flicker line at power on. From what i read here, it looks like one of the S-RAM chips finally went, which would explain the random crashes if the cart connector wasn't seated jusssst right; or maybe using a gen-1 Everdrive N8 since 2013 finally did it in with the voltage differences or something... i don't know. I don't have the equipment or the experience to deal with that, so i'm not going to bother for a while... anyway...

I just picked up an '08 Toaster yesterday. Plugged it in, uh-oh, wavy lines everywhere. Yuck! It has this exact problem! Both RF and Composite are affected about the same, as far as i can tell.

The first thing i tried was a different power adapter. I plugged it in with a One-Spot 9V Adapter meant for guitar pedals... It alleviates the issue! Nice! However, i wouldn't call it "fixed" by any means.

Image
With NES-002 Power Adapter directly captured. Yuck! It moves a ton and looks even worse on CRT, trust me.

Image
With One-Spot 9V guitar pedal adapter. Better! The movement is minimal, the interference is dimmer, but, it is still an issue.

So, if you are looking for a "quick fix", the 9V guitar pedal adapter is 20 bucks, fits in the jack, and seems to help a ton.
https://www.guitarcenter.com/Truetone/1 ... 5035973.gc

I also tried moving the '08 board to the '07 chassis, as an on/off switch issue was suggested as a culprit in this thread. Alas, that had no effect.

Now, my old dead '07 had crystal clear video output (as far as composite goes) with the same NES-002 adapter that causes interference on the '08 i just bought. The RF / Power box in the '07 is a Mitsumi. The '08 i just bought has an Alps RF / Power box. Hmm... It could just be the capacitors i suppose, but, I wonder if this is an issue that affects Alps boxes...

My next step is to take the Mitsumi RF / Power box from my dead '07 and put it in my '08. If / when i do this (and i don't blow anything up) i'll post the results. Hopefully i can get my "good" video quality back!
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Ben Boldt
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Re: Wavy Lines on NES-001 - but there's something more to it...

Post by Ben Boldt »

If it does follow the RF box, make sure the Composite video RCA connector is clean and rust-free, also inside the hole. It may need something abrasive such as a scouring pad or steel wool to shine it up.
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