WG6100 Half Screen Missing

Cavern Arcader

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Hello all,

I am currently working on a WG6100 and have an issue with half the screen missing, specifically the top side of the Y-Axis on the monitor (Using standard orientation meaning X-axis is the long one and Y-axis is the short one).

To date I have installed a Ian Kellogg Total Rebuild kit (less frame transistors as he was out at the time), I have tested all the frame transistors at the P-connectors and they are fine.

By connecting my oscilloscope to the X and Y outputs on the game PCB I am able to see a complete picture so I believe that the issue is in the Y-axis circuit of the deflection board but not really sure what it may be. I have measured voltage on P600, Pin 1 as 26v and on Pin 7 as -26v, only thing that seems slightly out was on Pins 4 and 5 I measured 1v instead of the .05v

Please see attached photos for reference, any help would be greatly appreciated.
 

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Bad solder joint, or bad transistors on the deflection board (the ones with the tall fins, or the TO-92-packaged ones behind them). Also, if your deflection board has the Input Protection Circuit (IPC) daughterboard installed, check the solder joints where it meets the deflection board as well, as the wire legs like to loosen up and pull out of those joints.

You can test all of the transistors with a DMM without removing them, using the diode test function. The X and Y sides are nearly identical, so you can compare both sides of the board if you are unsure what to expect.
 
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