SNES jr blew fuse after replacing caps, other issues halp me

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rezendes
Posts: 5
Joined: Fri Sep 26, 2014 11:46 pm

SNES jr blew fuse after replacing caps, other issues halp me

Post by rezendes »

Alright, I have an NTSC SNES jr mini etc SNN-CPU-01 that I have the RetroRGB RGB board installed on. The system was running perfectly so I decided to ruin it by replacing the caps that have been in the system since the 90s. Seemed like an easy job, replaced the caps double checking the values (didn't replace the 7805 voltage regulator). I turn on the system and I'm having sound come in and out, colors are off sometimes, eventually I stop getting any image or sound and I smell a bad electronics burning smell on the board. The fuse blew. I checked some points and found out the Input pin 1 of the 7805 was shorted to Ground. Checked the 7805 and it's fine and working as intended. Through the process of elimination while removing various chips I realize the short issues went away when I removed the F411B lockout chip. I found a spare F411A from the inside of one of my Super Gameboys and popped it in it's place, tested and no short. This time I stupidly was impatient and have no fuses and just bridged the fuse pads to test the system. No video/audio, same smell and the shorts are back again. This time I now see where the smell is coming from, seems the board is burning from the inside (see pics). I don't know what's happening nor know what to check next. Also, I'm using the oem power adapter SNS-002 although I plugged it into the wall and straight into my multimeter (no load) and it is showing ~15Volts not 10... Is that normal? I attached some pics, I know the RGB board looks like crap now but it used to look clean before removing it to check things out, everything is connected and not shorted. The burning spot is right next to the input of the Voltage Regulator.
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