resolution | horizontal bandwidth | # lines | # colors | comparable |
standard | 15.75 kHz | 240 | unlimited | CGA or NTSC TV |
extended | 16.5 kHz | 288 | unlimited | CGA or PAL TV |
medium | 25 kHz | 380 | unlimited | EGA |
high | 31.5 kHz | 450 | unlimited | VGA |
just another tip on degaussing a monitor.
place your game so it faces to the north or south when usind a degaussing coin as it will help in the process of degaussing as it lines up with the magnetic forces of the earth.
Wells gardner K7191 chassis numbers
The K7191 manual can be found here: (but this only pertains to the P447 board)http://www.mikesarcade.com/arcade/monitors.html (http://www.mikesarcade.com/arcade/monitors.html)
if you need the schematic for the P538 I can send it to you--it is different and does have a few key different parts than the P447 board
(http://forum.arcadecontrols.com/index.php?action=dlattach;topic=51525.0;attach=100877;image) Horizontal Collapse | (http://forum.arcadecontrols.com/index.php?action=dlattach;topic=51525.0;attach=100879;image) Vertical Collapse |
Question: What is the specific function of a 1:1 Isolation transformer? Isn't it supposed to keep the AC at a steady 60hz? Keep the spikes out so the monitor doesn't blink?I think Ken must have been misquoted here as this is not really what an isolation transformer does. In fact its the opposite. The function is to render the monitor chassis "cold" as opposed to "hot" and allow it to safely be connected to ground along with all other compnents in the cabinet. It does not isolate the chassis from the other componets in the cabinet, it isolates it from the AC power input. One side of the output of an isolating transformer should always be connected to ground and to the monitor chassis. The game board or PC ground is connected to the monitor ground by way of the video harness and so the monitor chassis must be grounded and definitely not "hot".
Answer (courtesy of Ken Layton): As pertaining to commercial arcade games the function is solely to isolate the monitor's "hot" chassis from all other components in the cabinet and keep you from frying if you touch the chassis. Only the monitor is connected to the output side of the transformer and nothing else. The transformer was not designed as a voltage regulating/spike protecting unit. It is a safety device for sure.
continued...That link to Bob Roberts' Monitor ID page is dead: Use this one instead:
Q: You said you would help me identify my monitor, so identify already...
A: Ah the impatience of youth... ;D
The best thing to do first is look for a tag or sticker that explicitly says what model you have. Please note that only manufacturer's and a few gifted arcade guys can identify using serial numbers --please find model numbers (it will say model:_____). Failing that, look for identifying marks on the boards themselves (chassis and neckboard) Sometimes there are numbers, sometimes there are letters that can help identify what it is you have.
Last bet, take as good a top down picture as you can--this may require you to discharge the monitor and remove it from the machine but since it's likely not working anyways you will be doing this regardless (more on this later)
Armed with your picture, visit:
www.jomac.net.au/mon.htm (http://www.jomac.net.au/mon.htm) OR
Bob Roberts-big bear bulletin board (http://homearcade.org/) and see "whats my monitor" about halfway down the page.
I recently contacted the author of the Powerpoint tutorial (discharge.ppt) and he gave BYOAC permission to post the file here for archival purposes. (Attached as a .zip file)The link to the PPt file in post 1 is no good anymore. And the zip DeLuSioNal29 posted is gone aswell..
A big thanks goes out to Russ from www.arcadegames.net for letting us use his great file. :applaud:
~ DeLuSioNaL
continued...
How to discharge a monitor:
See here for pictures and directions: http://www.arcadegames.net/sightsound/discharge.ppt (http://www.arcadegames.net/sightsound/discharge.ppt)