Operation Wolf loss of -H sync

Zinfer

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K7000 Monitor tested out with TPG - working great. However there is no sync being delivered with the white wire. Wire toned out long ago.
Is there an area of the pcb which controls sync? Is this a known or common issue?
 
H-SYNC comes from IC33 (PC080SN) Pin 13
V-SYNC comes from IC33 (PC080SN) Pin 64
 
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Do you know if these signals originate from the 080SN or from upstream that custom?
 
Well, it could not that bad. The H and V syncs need to be combined to a composite sync, hopefully this is handled downstream the custom 080SN.

First, I would measure frequency at the pins that SamWhiskey mentioned, a good multimeter should have a frequency meter and although this may not be the most appropriate tool to use, you may get a feel is the signal is there and if it is stable. Horizontal should be around 15.7 kHz, vertical at 60Hz.

If the signals are good and steady, follow the path from those pins to the IC that is next and check the functionality. If you can't check functionality but have a known good replacement, you may be able to piggyback it with that. See what happens...

Good luck!

paris
 
Schematics found here:

http://www.arcade-museum.com/manuals-videogames/O/Operation Wolf Schematics Complete.pdf
and here:
http://www.arcade-museum.com/manuals-videogames/O/Operation Wolf Schematics.pdf

Looks like the H and V are combined by IC 15, LS164. Look at page 8, it is shown there. I would check the frequency at pin 1,2 (for vsync) and pin 8 (for hsync).

Also look at IC 19 (a PAL device I believe) on page 10, looks like the h and V syncs are combined there to composite sync for output to the edge connector.

paris
 
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