Service manual

Wells-Garnder Color Vector Monitor Guide
Page 8 of 73
"Type-1N4001 Diode (D104-107, 602, 702)".
• "Type-2N3904 NPN Transistor (Q804)" added.
• "10K Ohm, +/-5%, ¼ W Resistor (R812, 813)" added.
• "...2W Resistor (R106)" changed to "...3W Resistor (R106)".
• "5-Amp ... (F100, F101)" changed to "6.25 Amp ... (F100, F101)".
• "18K Ohm, +/-5%, ¼ W Resistor (R811)" added.
• "30K Ohm, +/-5%, ¼ W Resistor (R810)" added.
• "Germanium-Special Diode (D807, 808)" added.
Monitor Board Revisions
There are several manufactured variations (and many more upgrade variations) of each of the
three monitor boards (at least three for the deflection board and two for the neck and HV boards).
The original designs are labeled P31X and the newer; more fault tolerant designs are labeled
P32X. There are also deflection boards labeled P339 so there may be a whole 33X series as well.
To add to the confusion, the Wells-Gardner service manual for the "19K6400 series color vector
monitors" shows a P341 version of the neck board, a P324 version of the HV unit, and a P322
version of the deflection board. You will most likely never see any of these boards, as the
19K6400 was only used in Centuri’s Aztarac.
Here is how to identify the versions of the Wells-Gardner 6100 boards. The deflection boards are
P314, P327 and P339. Some P314s were upgraded most of the way to P327s with a small piggy-
back PCB on wire "stilts" at the top of the PCB (see "Input Protection Circuit", described later in
this document). The neck boards are P315 and P328 (P328 has a brightness adjustment in one
corner) and the HV power supply boards are P316 and P329 (P329 has an LED, HV limit pot,
and an extra electrolytic capacitor, C22, which is supposed to be 10uF at 63V). After much very
disturbing feedback about the performance of the monitors, Atari had all the boards redesigned
to be more robust. The P32X (and P339) versions are the newer versions of the boards.
A close inspection of the P339 deflection boards reveals that they are, in reality, P327s with a
P339 sticker covering the part number! Make the following changes to your P327, put a new
label on it and you will have a virtual P339! All other components are the same.
Differences between P327 and P339 deflection boards:
• C800-803 changed from .47uF @ 35V to 1uF @ 50V. (*)
• R701 (1.3K) changed from +/-2%, 1/4W to +/-1%, 5W. (*)
• R812-813 (1/4W) changed from 10K +/-5% to 5.6K +/-10%. (*)
• Q604/Q704 (NPN) packages are upgraded from TO-92 to TO-202 (NTE49). (*)