[cobaltmute]

1A = USB 5V
1B = 2.5V
2A = negative of 1A
2B = -2.5V
 
Other points are labelled.

 

[forsakenrider]

Sorry to be such a hassle!
 
1A =4.78
1B =4.15
2A = -4.75
2B = -2.52
4.75 = 4.7
3.3 = 0.09
2.5 = 4.16
-2.5 = -2.52
 
also U1 gets super hot very rapidly!

 

[cobaltmute]

Your 3.3 regulator is passing too much current.  As I said, follow the traces from it and check for shorts to ground on everything.  As a simple check, check the resistance on the output of the regulator to ground.
 
For the 2.5V regulator, it is not regulating.  Check for a short between 1A and 1B.
 
All the other points I'd be happy with.

 

[forsakenrider]

Ok, trying to icolate the problem. Ive removed L3 and L4and now 3.3 is 3.3! so I guess maybe U2 has a short? I really cant see where, I've gone over it with Desoldering Braid and a solder sucker. ALSO now 1B and 2.5 are giving -0.81. all other points check out. Ideas? Im all out of them.
 
 

 

[forsakenrider]

Does anyone have a good picture of an unpopulated board? that might help me better then the images on page one of this thread.

 

[forsakenrider]

Ok, it gets weirder! I changed U7 and now my 2.5 is back up to 4.15ish. I removed L3 and L4, re-installed L3 and U1 seemed to be fine, and my computer reconized it! ok, I thought its all better, installed L4, boom 3.3 back down to 0.81. removed L4 and its the same, removed L3 and its back to 3.3. Soo Iim guessing theres a short on U2 but I have no idea where or how to remove it now.
 

 

[cobaltmute]

I'm fairly busy at work right now, but I'll take a look at what you are saying tonite.

 

[c12mech]

I just got my board today and was planning to take pictures as I go.  I'll try and get some good close shots and post them later tonight.  This board is huge compared to the skeleton dac board.  Most all the parts I ordered are sitting in Florida waiting to be picked up on the next run to the states that the guys here do.  Hopefully I will have all of it by the end of the week. 

 

[forsakenrider]

OK more, I've gone over this thing like a mad man (I dont work today) and I think VDD is connected to ground somewhere... and I think it shouldnt be. yes? no? maybe? 3.5ohm <EDIT EDIT EDIT

 

[c12mech]

Hopefully this helps forsakenrider.  Best I could do at the moment.
 

 

[forsakenrider]

welli fried  my last 2.5 reg i think...but heres a weird discovery, i have no u9, L3, U7 and C34 installed. voltage at 1B started around 4.5 and is droping  0.01v per 2 seconds.
 
 
EDIT: I guess thats just a cap bleeding down, wow I'm really looking too hard.

 

[cobaltmute]

Quote:

OK more, I've gone over this thing like a mad man (I dont work today) and I think VDD is connected to ground somewhere... and I think it shouldnt be. yes? no? maybe? 3.5ohm <EDIT EDIT EDIT

Vdd which is 3.3v should be higher that 3.5 Ohm to ground. 
 
You have a short.  Which is why the regulator is not regulating - it is current limiting.

 

[cobaltmute]

Quote:

Ok, it gets weirder! I changed U7 and now my 2.5 is back up to 4.15ish. I removed L3 and L4, re-installed L3 and U1 seemed to be fine, and my computer reconized it! ok, I thought its all better, installed L4, boom 3.3 back down to 0.81. removed L4 and its the same, removed L3 and its back to 3.3. Soo Iim guessing theres a short on U2 but I have no idea where or how to remove it now.
 

Okay.
 
Seems like you have some weird shorts.
 
I check for bridges by looking at the pins I want to check and then tilting the PCB to look down between the pins (rather then from above).  I also find it helps to have the board turn so the row of pins is perpendicular to your body rather than parallel.  I have had bridges deep behind the pins, which the only way to fix was to add more solder to touch to bridge and then wick it all off.
 

 

[cobaltmute]

Quote:

welli fried  my last 2.5 reg i think...but heres a weird discovery, i have no u9, L3, U7 and C34 installed. voltage at 1B started around 4.5 and is droping  0.01v per 2 seconds.
 
 
EDIT: I guess thats just a cap bleeding down, wow I'm really looking too hard.

You are correct on the cap - it is C31.
 
What are you using as the ground when you measure 1B?
 

 

[forsakenrider]

All my measurements use one of the corners for ground or the spot beside 1A.
 
Could the short be because of my trick? I usually use a little bit of thermal paste to hold the larger IC's in place when soldering. It says its not conductive to electricity.
 
I have looked from all angles, I guess I will cover all the pins with solder and wick it all away.