Hi folks! Once again I am stumped and asking for some assistance.
This is another scope I have been refurbishing. The power supply has been fully gone through and has all new filter capacitors and 1 new bridge rectifier. It has been well cared for in regards to being kept indoors, loved and not abused. But the previous owner did not attempt to make repairs and it had 6 or 7 different issues. I traded a fully refurbished 2445A for it (plus front cover and a 475A service manual) since I liked it so much (I have way too many scopes!). Anyways, this is the final issue.
Tektronix 475A, when Horizontal Display - B Delayed is selected only the A Trigger Slope knob allows me to trigger and light the triggered bulb. The B Trigger slope knob was previously showing some changes to the signal. When there was a single bad tunnel diode in the circuit and you turned the B knob to the right the trace would just fold up and disappear. But in regards to actually triggering the signal it has had no effect even after I replaced the bad tunnel diode and corrected that situation.
When B'Dly'd is depressed J2-6 changes from 5v to -8v and I did check transistors in the various horizontal circuits branching from B Dly'd but I was hoping someone can help narrow down what circuit might allow this to happen. I have not checked any components on the A7 Timing board yet since its hard to get to.
Timothy