nesdev.org

Hey guys, hoping someone out there has some tips for me.

I have a dead Snes Jr. here. When I power it on, I get absolutely nothing. No screen flicker, nothing. I'm using an original SNES-002 power adapter, but it seems like the voltage is pretty high. I'm seeing ~14v off of it. I've tried also using a good ~9v adapter (from my NES) as well as wiring a 5v supply line directly into the output of the 7805 and still nothing.

When a power supply is plugged in and the console is on, I see no voltage on either the input or output of the 7805. I've checked and I'm seeing a good voltage across F1 as well as T1, and a few passives near the underside of the power jack.

I'm at quite a loss here. Does anyone have any ideas on other components I could try? Either that, or a schematic of the SNES Jr.? I found one for the regular SNES but I'm not certain they match.

Also, a side question: It looks like pins 5 and 6 of the AV connector are bridged. Is that normal?

Yes, pins 5 and 6 are both ground: http://problemkaputt.de/fullsnes.htm#sn ... torpinouts

It sounds like you don't have voltage anywhere. It might be a short, or something open. The standard way to diagnose this is to start at the power jack and measure for voltage, and then follow the traces until it disappears.

If you have absolutely nothing, the first thing to do would be to check the fuse. Use the continuity setting on your multimeter and touch both sides, it should beep (a working fuse is basically just a wire, a blown fuse is like a wire that's been cut). It's a decent-sized white block near the power port, kind of tucked under the RF shield. It's marked 1500 (i.e. 1500mA fuse).

Do not plug a NES adapter in for power- those output AC not DC.

FrankWDoom wrote:Do not plug a NES adapter in for power- those output AC not DC.

You wouldn't be able to anyway, the plug shape is different. The SNES has a much larger inner and outer diameter barrel jack.

lidnariq wrote:Yes, pins 5 and 6 are both ground: http://problemkaputt.de/fullsnes.htm#sn ... torpinouts

It sounds like you don't have voltage anywhere. It might be a short, or something open. The standard way to diagnose this is to start at the power jack and measure for voltage, and then follow the traces until it disappears.

Thanks for clearing the pinout up for me! As for tracing the power line, that's basically what I'm asking. It's hard for me to see where the traces are going. I was wondering if someone knows offhand what would be in between the fuse and the 7805.

qwertymodo wrote:If you have absolutely nothing, the first thing to do would be to check the fuse. Use the continuity setting on your multimeter and touch both sides, it should beep (a working fuse is basically just a wire, a blown fuse is like a wire that's been cut). It's a decent-sized white block near the power port, kind of tucked under the RF shield. It's marked 1500 (i.e. 1500mA fuse).

Sorry, I should have been more clear. When I said F1 and T1, I meant the fuse labelled T1 which is the one you are referring to. So the fuse looks good unfortunately, I'd love for it to be the fuse though! Do you know where the power goes after it goes through the fuse?

qwertymodo wrote:

FrankWDoom wrote:Do not plug a NES adapter in for power- those output AC not DC.

You wouldn't be able to anyway, the plug shape is different. The SNES has a much larger inner and outer diameter barrel jack.

Sorry I was unclear, I'm using an A/V famicom with a 9v DC adapter. I currently have a female jack wired straight up to the SNES since my SNES adapter seemed so high.

I reexamined the fuse and it turns out it WAS bad! Thanks for everyone's help!