Marshall 2204 CSA HT Fuse

[bobloblaws]

That's normal before preamp tubes filaments have reached operating temperature.

There were no tubes at that point.

[Helmholtz]

There were no tubes at that point.

Then it's normal for the voltage to be high. And if the voltage at the reservoir cap later dropped caused by a bad contact/connection, preamp supply must drop as well.

[bobloblaws]

Then it's normal for the voltage to be high. And if the voltage at the reservoir cap later dropped caused by a bad contact, preamp supply must drop as well.

OK, I will check for intermittent solder joints etc.

[Helmholtz]

Could even be an unreliable switch.

[Helmholtz]

Also I can confirm that a cap exhibiting increased leakage (because of having been shelved too long) typically self-heals with use.

[g1]

My point being at no time did you exceed the 500V rating of the caps (that's what they are isn't it?). Loaded, unloaded, that rating is all that matters. And that rating is for working voltage. They will withstand short surges of even higher voltage.

I'm using a Fluke 175 and I double checked with a Hioki 3802. What do you mean "you want to be very sure about it"?

Should you want to return them as defective.

[bobloblaws]

OK, thanks guys for helping put my mind at ease!