SOLVED: Please help with my N64 portable wiring job

[kevin12331]

Hello everyone, this is my first post. Good to be on the forums.

- 2 hot wires (little over 7.5v) run to the 8080 step down regulator, and to the 7.4v solder joint on the N64 board.
- 2 negative wires run to the step down regulator, and to the negative connection on the board.
-1 hot wire runs from my 8080 to the 3.3v connection on the board

As soon as I connect the negative to the board, I have problems.
Using a multimeter, with the negative DISCONNECTED , all my readings are normal. I have confirmed 7.4v going to the board, and 3.3v going to the 3.3v slot.

However, when I connect the negative to the board: 7.4v remains hot, but my 8080 goes cold. There is input on the neg and positive, but I dont get any 3.3v output anymore.

I have no idea why, I'm not very experienced with electronics. Please provide information. Thanks. I'm happy to answer and questions about my setup. Sorry for the hack n slash wiring job.

 

[Fluxedo]

Re: Please help with my N64 portable wiring job

Most likely have a short in the 64 board itself. Make sure there's no loose wires anywhere or stay solder beads or small pieces of copper that might be clung to the board. If none of these, do a full clean of the board. Try some compressed air

 

[kevin12331]

Re: Please help with my N64 portable wiring job

Thanks for your reply.

I've looked about my board and cant seem to spot any obvious signs of debris, or extra solder.

Is there any easy way for me to troubleshoot this with my multi meter?

also, why do you think it's not a problem with my voltage regulator? It no longer puts out 3.3v when i connect the n64 boards negative

 

[Fluxedo]

Re: Please help with my N64 portable wiring job

De-solder your regulator from the board and test if 3.3v is connected to ground with the resistance setting.

If you get a connection, you're board has a short somewhere and you'll need to find it.

If you get no connection, try powering the board from the original power supply and see if it works.

I don't think it's your regulator because you said that when you remove it it continues to work. I'm pretty sure the TI regs have a protection circuit built into them to not fry when theyre bridged.

 

[kevin12331]

Re: Please help with my N64 portable wiring job

Okay that makes sense. I agree with you, I think there is a short in the board.
Is there a good method for finding that? besides looking over every square mm on the board for solder or copper strands? thanks

 

[kevin12331]

Re: Please help with my N64 portable wiring job

I found the short. A small piece of copper that bridged 2 of the processor's pins. Just wanted to say thank you so much for your input!

 

[Fluxedo]

No problem. Always make sure you check for things like that before wiring. It can save you good money and time.