1,341
edits
465/Repairs: Difference between revisions
Jump to navigation
Jump to search
m
add missing )
m (→Problematic Transistors: transistor subsections) |
m (add missing )) |
||
| Line 58: | Line 58: | ||
<li>Study the CRT Supply Schematic (keep on mind that you need to use the schematic for your specific scope). </li> | <li>Study the CRT Supply Schematic (keep on mind that you need to use the schematic for your specific scope). </li> | ||
<li>Check and note the specific wave forms at each test point (indicated by a numbered Black Hexagon) on the schematic. These are illustrated on a page preceding the schematic.</li> | <li>Check and note the specific wave forms at each test point (indicated by a numbered Black Hexagon) on the schematic. These are illustrated on a page preceding the schematic.</li> | ||
<li>Check for a strong sine wave oscillation at the collector of Q14009 (Waveform 92 in the 465B early manual. A "weak" sine waveform of less than 2 or 3 V p/p indicates trouble.</li> | <li>Check for a strong sine wave oscillation at the collector of Q14009 (Waveform 92 in the 465B early manual.) A "weak" sine waveform of less than 2 or 3 V p/p indicates trouble.</li> | ||
<li>Next, check voltage at the base of Q4228 (on 465B-Early) schematic shows this should be about 0.7 V<sub>DC</sub>. With a "shorted" HV Multiplier, you will likely see 4.5-4.8 V<sub>DC</sub> on the base of Q4228. | <li>Next, check voltage at the base of Q4228 (on 465B-Early) schematic shows this should be about 0.7 V<sub>DC</sub>. With a "shorted" HV Multiplier, you will likely see 4.5-4.8 V<sub>DC</sub> on the base of Q4228. | ||
<ol style="list-style-type:lower-alpha; margin-left: 3em;"> | <ol style="list-style-type:lower-alpha; margin-left: 3em;"> | ||