On Thu, 1 Sep 2016 19:24:18 +0100, "Ian Field"
wrote:



wrote in message
...
On Saturday, August 27, 2016 at 9:47:06 PM UTC-4, wrote:
i am trying to repair a video slot machine. the monitor image is not
correct. the image is shifted to the left and cut off. there is a black
vertical bar, about 15% of the screen size in the right 3/4 of the screen
. to the right of that is the beginning of the image that is shifted to
the left. i took the monitor to a repair shop, and he says the
monitor/chassis is ok. i'm not too sure about that. a different mpu in
the slot has the same result. its a tatung VT-1440S monitor, VGA . i
would like to hook up a desktop vga monitor.

i posted an image from the slot schematics he
http://s408.photobucket.com/user/mho...GA%20interface

is it possible to hook up the LCD monitor to test the machine? i made a
cable with a female db-15 and individual pins on the other end.

thanks much
mike

When my buddy was in the vending business, I repaired several hundred of
his monitors, many just like this one. I seem to recall a horiz phase
adjustment on the main board. Sometimes just tweaking this pot would lock
in the picture.

The phase comparator compares the sync with a pulse from a winding on the
horizontal transformer. Its fed by a high value resistor - going high or
open is a very common fault.


This happens very rarely but I've seen a cap to ground open on this
line which causes the picture to shift.

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