When did the ps2 5v to 3v conversion begin?

I don't know a specific model, but I believe 2004 was when the 3V boards started appearing.  Within a year or so, the 5V boards were no longer being shipped.

3V board showed up first with #1 gauge.  As early as 2001.  The 70-3001-1 is 3V board.  Can't say exactly when it showed up  in O, but there seemed to be a transition period where both were used.  G

I didn't realize it was around that early George, I don't recall any O-gauge locomotives before around 2004 with 3V boards.  I did a sampling of the 2003 Volume 2 catalog, and all the user's manuals I checked depicted a 9V battery.

I'm inclined to think it was about 2004 for O, because that's when the upgrade kits appeared and their purchase began to show up in my records.  I don't know how much time elapsed between inclusion in factory locos and issuance of the upgrade kits, but my vague recollection was some months.

My memory tells me RJR is correct.  Remember, the first few years the 3 V board was a 1 meg file.  The same goes for the early upgrade kits. The 2X memory boards did not show up until about 2007.  At that time it started showing up in upgrade kits.  If you have an upgrade kit or 3V board, the easy way to determine what you have is to look for the word SHARP on the large component on the processor board. 

Gerorge, I never had anything to do with the large gauge and I have heard what you stated.  If someone looks up one of those engines, we can tell from the file number. 

When you punch up an engine and look at the sound file, start counting left to right and position seven will usually be a 3 or a 5.  This is a good general guide to determine what boards the engine may have.

I looked up several of the 2001 #1 gauge locomotives, they all had 3V boards.  Obviously, that was their proving ground.  The first O-gauge I remember having 3V boards is a 2004 one.

That means MTH dumped the 5-volt system pretty soon after it came out.  Weren't the fiurst PS2 locos about 199 or 2000, well before DCS was released in 2001?

Yep, before that it was PS/1.  I suspect some of the shortcomings of the 5V boards became apparent pretty quickly, especially the part about not being able to repair them.

The market was flooded with PS2 locomotives long before the DCS system came out.  It worked out for dealers as none of them were stuck with PS1 locomotives.  I had DCS a long time before it got released.  I remember at that time I had about fifteen PS2 locomotives to work with on my testing.

Not only was PS-2 5V short lived, it when through many revisions.  REV G, H, I, and finally K with modification on each variant.  The last REV K foot print is significantly different then the REV I. 

The other funny issue to me is that many of the 97, 98 and above PS-1 engines have frame cut outs already for the PS-2 guts.  Square holes for volume pots, extra switch cut outs.  Always looked like they were behind getting the first PS-2 board out, but were ready for it with production of the engines.

I seem to remember working on a PS-2 3V from the 2003 period.  So who knows they may have tested the water with a few PR engines by that time.  Some of those were the 2 AA battery types.  I also think there was a PS-2 5V or so still in 2004, but they could have been a delayed production from a 2003 design.  G

George,

Not only was PS-2 5V short lived, it when through many revisions.  REV G, H, I, and finally K with modification on each variant.  The last REV K foot print is significantly different then the REV I. 

Are you referring to TIUs or PS2 boards? If TIUs, I've never even heard of a Rev. K. Could you please describe it?

Thanks!

The ps-2 boards.  Under the square rectifier on the leading edge of the top board is a silk screen revision identifier for the board.  G