zw-l & PS-1/PS-2

Wow, I'm surprised.  I run only conventionally, and all of my PS-1, PS2, and PS3 run fine, including my first O-gauge steamer, a very old Railking Y6B, which has a couple of hundred hours on the ZW-L. No problems. 

I'd check that it's wired correctly, etc.  

You didn't say if you have run a Lionel, Williams, and other brands on it.  If not yet, I would not until you check wiring, voltages, etc: maybe it kills everything? 

I don't have any info on the PS2 part, but PS-1 may be hit or miss.

I have 2 PS1 engines (that I have tried so far) on the ZW-L.  I believe the first one I tried was the WVP&P Shay, which I am pretty sure worked fine.  I later tried a NYC Empire State Express Hudson, and had similar results to you, it would not come out of the reset state.

-Dave

Although I don't have any MTH locomotives, I understand that some early PS locomotives do not operate correctly with a chopped sine-wave type of transformer.

I'm sure that one of the experts will chime in to either confirm this, or confirm that I'm wrong. 

1st question, do they have good and charged batteries in them?  If so, when you first power up the PS-1 locos with issues, do you get the startup dings and then the sounds start, or do the sounds just start going?  If no dings, they are locked in neutral.  2nd, how much power are you giving them.  If the power is too high, they will not leave reset.  Of the nine that I have, so are very picky about high voltage to leave reset, and others seem to leave reset with no problem.  As for the chopped wave thingy, all mine don't seem to care, except that the horn will go off sometimes.  Placing a lighted caboose or passenger car fixes this for me.  But the 1st time it happened, it really put me for a loop, as my loco wouldn't go afterward.  Being you can lock direction with the horn button pressed when you turn the power to the track off, it had entered lockout from the horn going off even though I wasn't pushing the horn button.

My zwl works fine with both. In fact I was able to unlock the direction lock on 2 ps2/3 engines using just my zwl with no issues.