Service manual

Wells-Garnder Color Vector Monitor Guide
Page 7 of 73
Manuals
Some words of caution about the Atari manuals. There are three versions of TM-183. If you are
lucky enough to have a copy of the Wells-Gardner service manual for this monitor (as opposed
to the Atari manuals), the parts list on page 31 has an error; it lists C916 as 0.35uF when it is
really 0.035uF. It is labeled properly in the schematic on page 28. None of the manuals show all
the different versions of this monitor.
The following describes the significant differences from the 2nd printing (without noting the
layout changes such as replacing the crummy photographs with clear, sketched, exploded-view
diagrams and minor rephrasing that are sprinkled throughout). All figures in the 3rd printing
show later versions of all boards with the exception of Figure 13, which still shows the old
deflection board (even though the parts list and all documentation refers to the newer versions;
obviously a mistake). Section 3 (Adjustable Controls) describes a later version of the neck board
(P328). Section 5 (Purity, Convergence, and Tracking Adjustments) is completely rewritten and
is MUCH less vague and more complete (two pages longer). Section 6 (Details of Operation) has
a section, which discusses the Input Protection Circuit and has a schematic (Figure 8), too. There
is also a new section G (Over-Voltage Protection) that describes the new circuit in the later
version of the HV unit (P324).
The 3rd printing fixes some typos in the deflection PCB parts list:
• "(R606, 706)" split off to "4.7K Ohms, +/-5%, ¼ W Resistor (R606)". (*)
• "(R612, 613)" changed to "(R612, 613, 712, 713)".
• "(C604, 704)" changed to "(C104, 105, 604, 704)".
• "(C800, 801)" changed to "(C800-803)".
• "7-Circuit Header Connector (P100, 600, 700)" added.
• "(Q600-602)" changed to "(Q600-602, 700-702, 801, 802)".
• "(C600, 601)" changed to "(C600, 601, 605, 700, 701)".
• "4.7K Ohm, +/-5%, ¼ W Resistor (R813)" added.
• "(R602, 603)" changed to "(R602, 603, 607, 702, 703, 707)".
• "Ferrite Bead (FB600)" removed.
(*) R606 is incorrectly listed in all manual versions as being 1/4W when in reality it is always 1/2W.
Unfortunately, the 3rd printing also introduces one error:
• "D104, 105" is changed from "Type-1N914B" to "Type-1N4001".
DO NOT MAKE THE ABOVE SUBSTITUTION, AS IT WILL NOT WORK!
D104 and D105 need to be 1N914Bs.
Some changes in the manual revisions were also due to part upgrades and/or additional circuitry:
• "(Q800)" changed to "(Q800, Q805)".
• "Type MPSA56 PNP Transistor (Q101)" changed to "PNP Transistor (Q101)".
• "Type-1N914B Diode (D104, 105, 600, 601, 700, 701, 801-804)" changed to
"Type-1N914B Diode (D600, 601, 700, 701, 801-806, 809-812)".
• "Type-1N4001 Diode (D106, 107, 602, 702)" changed to