Remember a few weeks ago in the post When it Rains, It Pours! I said that the Lacewood V2 reservoir capacitor had likely failed? Well, I was wrong.
I ordered a new capacitor but while I was inspecting the amp I saw something odd. The 350Ω/5W dropping resistor has a small hairline crack all the way around it. It still measures 350Ω but it doesn’t look so good. In addition to the crack, the writing is faded like the resistor got too hot. So that will be getting replaced with a 7W version.
However, when I desoldered the leads from the capacitor and checked it, it was fine. The capacitance values were very closed to specification and well matched. And the dissipation factors were still better than the new component I ordered to replace it. So I decided to keep the original capacitor and just replace the failed resistor. It is highly likely that the Magic Smoke I smelled when the amp first failed came from the resistor and not the capacitor.
The unit is still sitting on my desk, but when I get the repair complete and checked out, I’ll post an update.
As always, questions and comments are welcome.
I would test the capacitor more thoroughly. Hook it up to your variable bench supply and walk the voltage up to its rated voltage. Keep an eye on leakage current, let it sit there for a while. I have found many capacitors that test good on my tester, but arc over when normal full voltage is applied.
I enjoyed reading the update, and I am looking forward to hearing what you find after replacing the resistor!