nes board short?

Guest · Post by **Guest** » Sun Mar 13, 2005 6:56 pm

Im making an nes portable (out of an actual nes board), and i have a power supply/video amp built.

when i was about to hook it up i thought i should check to make sure there isn't any shorts on the nes board, and, to my suprise, theres continuity between the +5 and ground.

is this right? i have checked another nes board (dead) i have and it doesn't have this short ( it still has the power/amp thing still attached), and how im afraid to connect it all up.

so, i was woundering if this is supposed to happen, or maybe any ideas as to what may be causing it.

JackFrost22 · Post by **JackFrost22** » Sun Mar 13, 2005 8:30 pm

the five points
ooooo Some solder might still be on them

Post by **Gamelver** » Sun Mar 13, 2005 9:21 pm

I'd suggest tracing the 5v line and seeing if along it's traces if there's some solder or metal lying on it and making it touch ground somehow.......if not, then replace the 7805 and try it with the that

.

Guest · Post by **Guest** » Sun Mar 13, 2005 9:47 pm

Ive already traced the +5 line and couldn't find anything, theres no obvious shorts on the board, I wonder if maybe a component has failed, like one of the disk capacitors that are all over the board. Ill take another look.

Guest · Post by **Guest** » Mon Mar 14, 2005 11:23 pm

i may have found the problem, i believe it may be a capacitor, a 103z disk type, that doesn't behave like i think it should, hopefully thats whats the problem.

on an unrelated subject....
i was going to test my NESp powersupply, and the after i connected the battery, and was about to touch the testleads to the board.....(crackling sound) "SNAP!!!" (sparks). My crappy heatsink, from a dead 2600 board, contacted the output of the 7805, and it only took a couple seconds for it to fail, causing a small explosion, like that of a firecracker, my ears where ringing for a little afterwards.

if i had a camera i would post pics, its in several peices, and the input leg is completely vaporized, some of the heatsink is gone, and theres black silt all over the board.

ill have to be more carefull, those things arent as though as i thought.

Post by **gannon** » Tue Mar 15, 2005 8:47 am

Also, never directly connect the original nes power supply to a 7805!
It needs to go through a bridge rectifier first.

HK-47 · Post by **HK-47** » Tue Mar 15, 2005 3:27 pm

gannon wrote:Also, never directly connect the original nes power supply to a 7805!
It needs to go through a bridge rectifier first.

So its a ac power supply? Wierd? Dont most psu's output dc, not ac? Though thanks for the head up, if im doing more portable stuff I guess I should check the psu first!

Post by **SpongeBuell** » Tue Mar 15, 2005 5:07 pm

it gets converted to DC right away, and you can use a DC adapter if that suits your fancy. I have used a DC Genesis adapter in the past, not problems

Genius · Post by **Genius** » Tue Mar 29, 2005 4:25 pm

i may have found the problem, i believe it may be a capacitor, a 103z disk type, that doesn't behave like i think it should, hopefully thats whats the problem.

Have you figured out if this was the problem and have you fixed it? Because i seem to be having the same problem with mine

. I have the wiring hooked up exactly like ben says in the book but i'm not getting any power to the +5 volts on the board but instead getting 5 volts on the ground instead.