Question U10 woes. (Sound familiar??)

[whitmaker]

In trying to make a Noldendo, I soft-modded my 6 layer board.
After relocating U10 and running the line to the CPU, no boot. (red light goes green for a fraction of a sec and then goes out)
If I disconnect that line from pin 4, I get a green power light and normal voltages at all points but no boot. If I touch the wire to pin 5 (3.3v) for a moment, it boots.
There is no 3.3v present on pin 4, but constant 3.3v on pin 5.
I yanked U10 and went for U9. Same result. Could I have killed 2 of these chips in a row????

 

[randomguy]

Hello, I can't really say what is your problem but I recommend to check first this post

https://bitbuilt.net/forums/index.php?threads/rough-draft-u10-troubleshooting-guide.2317/

Hope it help
(And please post pictures)

 

[whitmaker]

Thanks! I did find that post. From what I gather, you could just connect ground and 3.3v to a U10 (or U9) and you're supposed to read 3.3v at pin #4. Is that right? If that's the case, could you power up, then flip a switch that sends 3.3v to the cpu contact and force it to boot?

 

[randomguy]

Yes that's it for the 3.3v line but please post pictures and check the continuity between your lined.Sometimes,the problem is just a bad solder joint.I dont really understand what you want to do with your switch for force the cpu ton boot,but you don't really need one normaly because it's the job of the U10(or u9)

 

[whitmaker]

I was just trying to get a "fool proof" way of determining if the U10 was fried. I took my U10 off the MB, attached wire from the 3 ground pins to the ground on the MB. I attached another wire from the U10 pin 5 to 3.3v on the board and powered up the board. testing pin 4 shows no voltage, so I guess the chip is toast. This test eliminates the possibility of the board being the problem.