Help with Mnats Little PSU [SOLVED]

Hey everyone. Been looking around for an answer to this one, but I haven't had any luck. Here's the situation:

I'm building a stereo 1176 using Mnats' boards and the separate power supply. I have everything in the boards currently, and my fuses finally came in the mail, so I figured I'd test the PSU to make sure it was working properly.

I plugged in the main power and flipped the switch. First thing I noticed was that only the red test LED on the PSU board was lighting up. Also, upon checking with my meter, it seems like the power supply is outputting only AC current instead of DC current. Nothing has started smoking or bulging or anything like that, and I've checked everything on the board as well as my transformer wiring at least 10 times. I'm almost certain everything is as it should be, I just can't figure out what's going wrong.

Any help would be greatly appreciated. Especially since once this problem is sorted out I can pretty much finish the unit (provided that nothing else goes wrong in the process).

Please link to project info; some of us can't remember all details of every project ever made.

http://mnats.net/psu.html
http://mnats.net/images/psu_full.jpg
http://mnats.net/files/MNATS_PSU.pdf

> seems like the power supply is outputting only AC current instead of DC current.

?? Do you have one of those meters that hardly knows AC from DC? Compared it to a 9V battery? Or known-good AC and DC sources? Tried new meter battery?

Is your PCB bought or self-made?

Verify that "CT" and "GROUND" are *Zero* Ohms apart (<<0.1r, though most meters won't read <~1 Ohm well). If there is a flaw here, all else will be goofy.

Meter Black on GROUND, what _DC_ voltage on C1 and C2? (Hey, what _AC_ voltage are you feeding to this?)

Do the polarity of the caps match the polarity the meter shows?

Did you get the LM317 and LM337 in the right places? Not only are they opposite polarity, they have different pin-outs.

> checked everything ....at least 10 times.

Bah. I once had a studio hung-up for months because I could not see MY simple mistake in re-connecting a repaired power supply. Self-checking is better than nothing but still not very good. When I had a slightly technical friend, I'd ask him to check and even though he didn't understand, he'd often ask the right "dumb question" to lead to my dumb mistake.

Thanks for the info! I'm still pretty new to the forums.

I have a fluke meter and on my other projects I've never had an issue reading DC voltage.

All my ground connections are reading right around 0.1 ohms.

I know that my regulators are in their right spots and oriented correctly.

I'm feeding 125v AC into the unit from an Avel Lindberg power trafo with dual primaries and dual 25v secondaries. Primaries are wired in parallel, secondaries are center tapped as per the instructions.

I'll have to check C1 and C2, but so far no matter where I've checked I've only gotten AC readings. DC readings tend to be very small at first and then slowly decrease to 0 over a few seconds.

Just did another check. Apparently my CT was nowhere near grounded! I must have checked just about everything else. Thanks so much, PRR! I don't know how long I would've been stuck on this if it wasn't for your help