Also, just something I noticed, once the relay clicks in, if I turn it off and wait a few seconds and turn it back on, the delay is about 8 seconds. I do not have the second P-700 board yet, and will probably wait to see if I get both channels before I go further.
When the timing cap is warmed up, having had voltage and current passed through it, it retains its capacitance and usual characteristics a bit easier on a fast turnaround. When the amp has sat off for awhile, the cap will discharge completely, and basically return back to its usual older, used up state.
If the timing cap is C807, it is in correctly and a 10uf 50v as per SM. I always replace value for value unless it is not available, then I increase the voltage rating till one matches. Thanks Rich
Just for grins, I pulled P800 again and checked all the solder connections and re-flowed the C807 cap, no change in the relay situation. What should I have for dc voltage before the relay and at the speaker outs? Thanks Rich
The Cap forms a "timing circuit" that is, the transistor that turns current and voltage flow to the capacitor once a threshold DC offset is met (below that threshold), then the capacitor charges up, and when it reaches a certain voltage, it fires another transistor to activate the relay coil, which then pulls the contacts together, allowing the amp signal to continue flowing to the speaker terminals.
With an old or failing timing capacitor, it either has changed capacitance, or developed leakage current which partly discharges while its trying to charge, slowing down the ability of the cap to fully charge. Also, many times ESR (equivalent series resistance) of the cap increases with age, which also reduces the current flow into the cap, thus taking longer to fill (charge) the cap, both of these slow down the timing circuit. Usually the amp circuit can stabilize DC in a few seconds, and then the timing (DC protection) circuit starts up and should everything be ok, allow the relay to fire in a short time.
