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Old 20th January 2012, 12:49 AM   #31
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I don't see a broken PC trace, but it looks like the U5 connects to the C6 and the D3 connects right to the AC adapter input. I tested the U5 bands one by one with the AC power plug in and got no readings from either. Did you mean put the red lead on all 3 pins at once or seperate because I did it seperate? That leads me to figure a short to ground on that trace. That probably sounds like what it is because there is no way two U5 are bad and I know I tested each peg correct. Please help further.
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Old 20th January 2012, 12:58 AM   #32
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Old 20th January 2012, 12:59 AM   #33
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Look at U5 to the left of it. Is that U6. Look at the bottom of U6, does that look like the bottom pin is connected to the pin below it? I could have sword I didn't see this with my eye and the flash caught it. Is this my problem?

NEVERMIND, IT JUST LOOKS LIKE THIS BECAUSE THAT PIN EXTENDS UPWARD AND OUT TO MAKE IT LOOK LIKE THAT. PLEASE HELP!!!!

Last edited by jschristian44; 20th January 2012 at 01:02 AM.
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Old 20th January 2012, 01:01 AM   #34
agdr is offline agdr  United States
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Red lead is only one one pin at a time! Don't use the meter probe on more than one pin or you will short things out.

Yes, that is how it goes, one adaptor pins connects to the unbanded side of D3, so there should be zero ohms between those two points. Then the banded side of D3 connects to the top outer pin of U5, so there should be zero ohms between those two points. You can follow the traces on the top and bottom and use your meter on the lowest resistance range, like 20ohms or 2 ohms, to check if traces are OK like this - with the O2 power off. Always unplug the ac adaptor from the O2 when doing resistance readings. You only need the ac adaptor plugged in for voltage readings.
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Old 20th January 2012, 01:04 AM   #35
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The middle of the pins on U5 looks a little burnt to the right but that's the only spot I can see. The others look pretty burnt elsewhere as well. Quick question, if I use this with batteries since it works will it charge it correctly or not? Do you think this is my error or a bad part?
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Old 20th January 2012, 01:12 AM   #36
agdr is offline agdr  United States
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Whoops - ignore my comment above about the solder mask. I was going by the board layout diagram. The O2 has a ground plane on top, but not on the bottom where you solder so it would be harder to short to the ground plane.

From your photo though I see a lot of what looks like solder bridges that shouldn't be there. Like the top pad of C6 has solder slopping over another trace to the right of it. You should clean up any solder like that with solder wick. Solder should not be bridging any pads or traces. C6 is to the right of U5 in your photo. To the left of U6 I see another bunch of solder bridging over from C7 (to the left of U6) to the trace to the right of it.

Batteries will not charge correctly if the AC power supply in the O2 isn't working.

Last edited by agdr; 20th January 2012 at 01:17 AM.
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Old 20th January 2012, 01:15 AM   #37
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Those solder bridges like the one on the top left and the one to the left of the U5 underneath are just the pins extended and then bended over near that piece that makes them look like bridges. They really aren't touching at all in the real thing I checked them all. The top part of C6 does have a little bubble underneath, but I can assure you it's not touching U5 at all.
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Old 20th January 2012, 01:20 AM   #38
agdr is offline agdr  United States
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Yeah, I just figured that out after pondering the photo a bit more. The angle of the photo just makes them look like shorts. Well good!

Well what I would suggest here is the resistance readings I posted above to check continuity of your traces. With the O2 unplugged and the meter in the low ohms range just test that trace from one of the adaptor jack pins to D3. Should be zero ohms. Then the other side of D3 to one of the U5 pins also zero ohms. Then D1 to the U5 pin on the other end, also zero ohms if all those connecting traces are good. And in each case measure the trace to ground - that should not be zero ohms, or you have a short to ground.

Because.. you measured +19Vdc to ground once on the banded end of D3. And if your resistance test here shows there is zero ohms (a good PC board trace) from the banded end of D3 to the pin of U5 closest to D3, then that U5 pin also has to be +19Vdc, which you were not getting. So figure that one out first!

Last edited by agdr; 20th January 2012 at 01:27 AM.
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Old 20th January 2012, 01:35 AM   #39
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Alright. I did the test between the D3, the power adapter jack, and the U5 pin. The first way with the ground on the D3 and the red lead on the other pins i got .001 and .000. Then when I switched it I got a 1.4 and a .8 and .000 in the U5 pins and .001 and 1.4 I think on the power adapter pins. It might have been the other way around though with the ground on the U5 pins when I got the .001 and .000 readings. But both ways those were the readings and I didn't know which one was legit since I didn't know where to put the leads to. The middle pin read .000 of the U5 when I did it the other way around. Does that mean that one is bad? That is the one where it looked a little too burnt to me.
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Old 20th January 2012, 01:38 AM   #40
agdr is offline agdr  United States
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Wait a minute. I just had another idea from looking at the O2 pc board trace diagrams on top and bottom.

There actually is a way for the trace from the banded end of D3 to U5 to be broken. That square pad on the banded end of D3 is a "via hole", which is a plated connection that connects the back of the PC board to the front of the PC board at that point. Sometimes those don't work quite right, in which case even though you soldered the banded end of D3 on the bottom of the board the voltage may not make it to the trace on the top. I also just remembered that raspunsen posted something about reading 8V on the lead of the diode, but +24volts on the square pad around it.

Try this. Solder the lead on the banded end of D3 on the TOP of the board, to that square around it, in addition to the soldering you have done underneath the board on that lead. Then see if that fixes anything. That would get around a bad via hole.
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