I've been working diligently on building a benchtop power supply from a PC ATX power supply as one of my first projects.
I'm looking for any advise about potential trouble shooting steps that I should take. Did I make a beginner blunder? I got to the end where all I needed to do was glue in the displays and bolt on the enclosure lid.
I tested it at this point and... nothing. The standby LED that I wired up from the +5VSB turned on, but that's all. Voltage in the various binding posts registered 0V or 0.003V (or very low). The fans don't turn on either.
I used these additional parts:
3-digit voltage meters:
http://www.aliexpress.com/item/0-28-Inch-2-5V-30V-Mini-Digital-Voltmeter-Voltage-Tester-Meter-LED-Screen-Electronic-Parts/32550332566.htmlVolt/amp/power meter:
http://www.aliexpress.com/item/50A-DC-Digital-Power-Panel-Meter-Monitor-Power-Energy-Voltmeter-Ammeter-Shunt-free-shipping/32432078283.htmlBuck boost voltage converter:
http://www.aliexpress.com/item/Z116-LM2577S-LM2596S-DC-DC-Step-Up-Down-Boost-Buck-Voltage-Power-Converter-Module/32243179400.htmlFor that, I desoldered the trim pots and soldered in 4 pots: 2 for voltage (fine and coarse), and 1 each for the current pots. I tested this independently and it worked.
+5V and ground are connected to a 30 ohm 10W resistor for a phantom load.
POWER_GOOD
--- sorry -- at this point it posted by accident... I'm continuing... ---
POWER_GOOD is connected to a blue LED and does not turn on (has a 100 ohm resistor in there just like the +5VSB standby rail).
+5V is connected to one of the 3-digit voltmeters. It doesn't turn on.
+3.3V is connected to one of the 3-digit voltmeters. It doesn't turn on.
+12V is connected to one of the 3-digit voltmeters. It doesn't turn on.
I also wired up -5V and -12V as well as an additional +12V that is wired to the volt/amp/power meter.
When I wire up a 12V battery pack to the inputs of the buck/boost converter, the PSU fans (both) turn on, the display lights up, and the +12V voltmeter display lights up (all these are on the +12V rail).
I'm a bit mystified as I walked over each and every tedious step at least 3x each to recheck that I was wiring things up properly.
Is the PSU dead? Do I need to rip it out and stick in a new one?
Any pointers are appreciated.