https://wiki.arcadeotaku.com/index.php?action=history&feed=atom&title=Circus_Charlie_Repair_LogsCircus Charlie Repair Logs - Revision history2026-04-19T22:06:41ZRevision history for this page on the wikiMediaWiki 1.42.1https://wiki.arcadeotaku.com/index.php?title=Circus_Charlie_Repair_Logs&diff=6965&oldid=prevDavewellington: moved Circus Charlie by Paul Swan to Circus Charlie Repair Logs2012-09-06T22:57:40Z<p>moved <a href="/index.php?title=Circus_Charlie_by_Paul_Swan&action=edit&redlink=1" class="new" title="Circus Charlie by Paul Swan (page does not exist)">Circus Charlie by Paul Swan</a> to <a href="/w/Circus_Charlie_Repair_Logs" title="Circus Charlie Repair Logs">Circus Charlie Repair Logs</a></p>
<p><b>New page</b></p><div>Repairer: Paul Swan<br />
<br />
BOARD NO: 0066<br><br />
GAME: Circus Charlie<br><br />
MANUFACTURER: Konami<br><br />
DATE: 1984<br><br />
HARNESS: KONAMI-S<br><br />
<br><br />
SYMPTOM (27/04/96)<br><br />
-------<br><br />
White virtical bars on background.<br><br />
<br><br />
SOLUTION<br><br />
--------<br><br />
Using a pulse injector on the ROM data pins indicated that EPROMS 4A and 5A held the background. The data bus of the two EPROMS were bussed together as was the address bus. Checking each data pin with a logic probe indicated that all the data pins were pulsing. Using a pulse injector on each data pin revealed that data bit D4 had no effect on the video when stimulated and this was selected as a candidate for further investigation. The EPROM data bus outputs were traced to the inputs of an LS273 octal flip-flop. A logic probe indicated that the EPROM D4 was being input to the LS273, but the output was always high. The other inputs and outputs were pulsing normally. Replacing the LS273 fixed the game.<br />
[[Category:Repair_Logs]]</div>Davewellington