Additinal info pulled from a web post ..
"You also have to change a couple of connections on the motherboard. A PAL configured motherboard has a few opposing triangles on the motherboard near location C-14 that need to be connected and some opposing circles that need to be disconnected for NTSC. PAL boards have the triangles separated by cuts. You can use a small wire and some solder to reconnect. PAL boards have the opposing circles connected with blobs of solder. Use solder wick and a soldering iron to remove the solder.
Rev 0 boards do not have this easy modification built into the PCB.
I wonder why they didn't use jumpers for this configuration change as it would have simplified the change from NTSC and PAL. The crystal needs to be changed out, as well, so I guess it doesn't matter"
and a copy of my post from Amibay...
I finally decided to try and revert my Apple II Europlus to an Apple II Plus
Basically the same unit ..but the Euro is PAL and the Plus NTSC.
Woz basically designed the Plus(NTSC) to use colour artfacting ..which sends pixels at specific times relative to the colour phase..
Call it a bodge or hack ..but it works.
In NTSC that is.
Sadly this method does not translate correctly in PAL systems ..thus ..no clour..
But if an NTSC capable monitor is used and the PAL undo mods implemented in the Europlus are reversed..
you have a PLUS unit.
The mod requires unsoldering links on the logic board ..soldering others..(I used removeable jumpers)
..and critically ..the systems crystal has to be replaced (I used a socket to keep it possible to reverse the mod easily)
The Crystal required has a frequency of 14.31818mhz and needs to be serial resonant..
These are tricky to find ..
which is why I took so long trying this.
anyway ..the result is that it works ..
You can see in one of the photos the same game output to a PAL crt monitor ..and an LCD muli system monitor which is NTSC capable.
appologies for the fuzzy photo images..
my camera is old ..and the lighting not great.
But this mod was on an Apple II Europlus ..so of course may not be relevant for a IIe ...
chances are this mainboard is totall different.
So appologies if I mislead anyone..