I finally got around to experimenting with the stray PS2 boards that I got in my big bag o'goodies a couple months ago. I know for a fact one is bad, it was marked as such and there's clearly a lot of no-good looking brown marks on it.
However, I also have one 5V and one 3V board that were both marked "good". So I thought there was a better than zero chance that they might be...well...good.
Checking the 5V board first:
- I've put a fresh 9V on (temporarily of course, just to make sure)
- Connected a smoke volume pot to pin 1 of the 12 pin connector that wasn't there, and soldered the other side to PC Ground (pin 10)
- Connected AC track power (Lionel KW Transformer)
- Turned up track voltage to 18VAC
- Connected 8 ohm speaker to pins 6 & 7
- Connected all smoke to the 4 pin connector and plugged into board
- Left the 5 pin motor connector unplugged (not connecting to motors ATM)
- Left the 8 pin (light harness) connector unplugged since I'm not checking those
So my results ...
Nada. No clicks, hums, buzzes, ticks, clunks, clanks, shivers. But also no magic smoke. It's as if there was no power anywhere on the board.
I checked the intput terminals (pins 7 & 5 on the 7 pin motor connector) and it was getting 18VAC. So I checked the long legs of the bige rectifier bridge, and I measured 18VAC at the "~" legs and 24VDC across the +/- legs. So the bridge is outputting DC to the board.
After that, nothing. I checked the 5V regulator that's plugged into the long wires, and there appears to be nothing on the red wire (I would expect 24VDC here to the middle pin since that's what the bridge outputs) and nothing on the yellow wire (Where there should be 5V to the middle pin).
So something between the bridge and the regulator is not right. Is it worth pursuing? Is there a "next step" I could take? I'm not afraid to replace a capacitor or solder a terminal, and I'm really just doing this to learn and for fun. But if I'm chasing components for 36 hours, then that's not fun. I could chase components for 6 or 8 hours, though, and feel satisfied that I resurrected a useful piece of equipment for the cost of a 2.00 capacitor. Just don't know the next place to check.
And I'm not needing to "send it in" or "Upgrade to PS3", mostly because I don't even have an engine to install this in! I'm just working with the board as-is to see what I can see.
Thanks for any "next step" type of thoughts! Pics of my board attached.
J
