repair of the intensity control on a tektrionx 317 scope

[KV8E]

I have a Tektronix 317 scope. the scope works fine except the intensity control has no effect on trace brightness. I have checked the voltages and the 400v unregulated supply is running at 450-460v. the other supply voltages r very close to correct. the voltage across the brightness control pot goes from +40v to 0v with the pot at the most cw position. seems to me the voltage must go - to dim the trace. other than this the scope works fine. any help on this problem??

[mzacharias]

https://elektrotanya.com/showresult?what=TEKTRONIX%20317&kategoria=&kat2=schematics


Page 85 of the PDF is where I would start.

[KV8E]

think I have and answer to my intensity control problem. the rectifier tube v824 may be bad. I ordered replacements and will put it in when they arrive. will keep all informed of process.  kv8e   doug