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chasing low brightness down the CRT bias voltages turned up some interesting notes. The blue background when maxed out would only bring up the G1 to 240v the schematic calls for 255v and it makes a big difference here. So I started by checking the resistance of the 1 meg resistors that couple the pot adjusted boost voltage to the G1s. I checked the blue G1 1 meg out the circuit and it tested at 6 megs. Replaced that one. The other two G1s had no problem getting two the specified voltage so I will leave them be for now (can't test in circuit and I don't want to replace something that is working, even if it has drifted as the pots can make up the difference).
While I was at it I check the 10k resistor that provides the boost to the pots, it was 16k. I have noticed that when it comes to voltage dividers you need to be pretty close to the correct values to have the correct ratios to divide the voltage by. Since I was low on G1 voltage and a drifted high resistor would make that worse I went ahead and replaced it as well.
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