Testing for a dead N64 Board? Video Output questions

[treminaor]

Hey guys, hoping someone can give me some quick help.

I've recently decided to continue a portable n64 that I stopped working on over 3 years ago and I have what I hope is a simple question:

I'm trying to figure out if my N64 board is dead or not. The light comes on but I have no video output and the audio output is just a buzz. I measured the audio output with a multimeter and the voltage is fluctuating like there's sound, but I don't hear anything. I have an old RCA cable wired to the board contacts, I'm not using the nintendo connector anymore because it's cut off of the board.

Is there a specific set of requirements before the board is guaranteed to output sound or video? For example grounding requirements? I noticed in the popular bacman wiring diagram he said the video output also needs to be grounded on the side of the board - is that true?

What's a good way to test if the board is dead or not if you can't get video output?

Thanks

 

[Aurelio]

I don't know how you wired your AV cable, but both Audio and Video require grounding connection

 

[treminaor]

I don't know how you wired your AV cable, but both Audio and Video require grounding connection

I grounded my video connection to the ground pin 4 and there's still no video output.

 

[Aurelio]

Can you post a picture?

 

[Noah]

Lol don't refer to any of Bac's stuff. 99% of it is flax and something better exists. As for where to connect ground to, there is no set place. Any ground on the board will work.

Pics pls

 

[treminaor]

Lol don't refer to any of Bac's stuff. 99% of it is flax and something better exists. As for where to connect ground to, there is no set place. Any ground on the board will work.

Pics pls

I've been powering my board using the 8.4v charger for my 7.2v batteries in order to test the console... I measured the voltage while the console was on and noticed it's severely underpowered. It's only getting 4v on the 6V line and 2v on the 3.3v line. So even though the red light is on, I don't think the console has enough power to work.

I'm guessing is this because the charger doesn't have enough amperage to power both the 6v line and the 3.3v line? I don't really have much of a background in electrical engineering.

Here's the picture of the video wiring... the yellow signal cable is soldered to the V pin of the A/V pins and the ground is connected to the side of the board with clips.

http://i.imgur.com/mLztnWh.jpg

 

[Prog]

It's probably a problem with the PSU, but it could be something damaged on the board. I'd try another power supply before anything else.
I don't know what you mean by your composite not being grounded. Do you only have one wire between your screen and your board? You will probably need two. (A standard composite video has two- the tip and the sleeve.)

 

[treminaor]

It's probably a problem with the PSU, but it could be something damaged on the board. I'd try another power supply before anything else.
I don't know what you mean by your composite not being grounded. Do you only have one wire between your screen and your board? You need two. (A standard composite video has two- the tip and the sleeve.)

Check out the image I just posted above you. The ground of the composite cable is connected to the side of the board with clips, and the signal wire is soldered to the V port.

I think you're right that it's a PSU problem based on what I just discovered with my voltages. I wish I could find the little power connector I cut off the board so that I could wire the board to the OEM Nintendo PSU brick for testing.

 

[Aurelio]

You CAN'T power the N64 with a li-ion charger. It is not a constant voltage source

 

[treminaor]

You CAN'T power the N64 with a li-ion charger. It is not a constant voltage source

That's pretty much the conclusion I reached from testing with a multimeter. I'm waiting for my li-on batteries to charge right now... trying to figure out a way to rig up the n64 PSU to the board without having the connector for it.

Edit: Just tested it with the N64 PSU rigged up to the board with some thick wires... correct voltage is now being fed to the console and still no video output. The video wiring is very simple so I'm assuming either my cartridge wiring is bad (unlikely but possible... it worked before and I hotglued it in place) or the board is dead. Gonna order a new N64 and start over with the board... this time I'm going to be more methodical in how much I take apart between each board test so that I can more easily narrow down the problem when/if something stops working.