Multinorm TV woes - no NTSC color display

["Linards Ticmanis" <ticmanis@gmx.de>]

Hello,

I've just acquired a small multinorm TV set (a Thomson 14 MG 135 to be
exact) to use as a monitor for various old systems. According to
advertisement, this TV should accept RF-modulated PAL and SECAM (B/G,
I, D/K and L/L' variants), as well as baseband PAL, SECAM, and NTSC
(both "real" NTSC 3.58, and the "NTSC 4.43" variant output by some PAL
equipment).

I've confirmed that the NTSC input basically works with the help of a
DVD player set to NTSC output (this would show only black-and-white on
my old TV).

However the TV refuses to display color for the signal from an Apple
II. This Apple is an Apple II Europlus with the following
modifications:

1.) I reversed the 5-jumper "Euroapple Modification" described in the
old Reference Manual.

2.) I replaced the 14.25something MHz Quartz with a 14.318something MHz
Quartz.

There is no PAL color card in the Apple.

Question No. 1, should this be enough to get the Europlus to create a
NTSC signal again. If no, what else do I need to do. Could the circuit
be detuned enough to lose color, and how would I tune it. The
replacement quartz was newly bought.

Question No. 2, does anybody know what parameters these multinorm TVs
use to detect a NTSC signal and identify it as such.

Question No. 3, how could I possibly get the Apple to produce a NTSC
signal this TV set "likes"?

Any help appreciated,
-- 
Linards Ticmanis