MOV or capacitor in Egnater rectifier section

[mechtonia]

My Egnater Tweaker 40 started blowing fuses and in the process of tracing the circuit, I came across a what I think is a capacitor across the input of the rectifier. Is this indeed a capacitor and if so what is it's purpose? Filtering? I have limited experience but I haven't seen a capacitor across the input of a rectifier.

Schematic of rectifier section of circuit:


Image of rectifier components:



Also, can anyone with Egnater experience confirm if this is stock/typical? This is on the bottom of the power board opposite a relay.

[PRR]

Welcome.

What is the component designator under the blue lump? (Like C41, D9, R69...)

In general, either a cap or a MOV here would be a just-in-case protection against different crap coming from the power line. (I do have doubt about how they implemented it.)

The other mod might be a poor factory change or a later owner's hack-work.

[mechtonia]

The component designation is C46. All other capacitors have a"Cxx" designation too.

[PRR]

Pull the handy HV fuses. Feed a 9V battery through a 1K resistor, each side one at a time, see if you get 7.8V (9V - two diode drops) at the other end, and if the 9V leaks from one side to the other

[mechtonia]

Pull the handy HV fuses. Feed a 9V battery through a 1K resistor, each side one at a time, see if you get 7.8V (9V - two diode drops) at the other end, and if the 9V leaks from one side to the other

Winner winner chicken dinner.

I performed the test as described and it failed. So I replaced the cap and everything looks good on the power front. Except the amp has no output. I made a new thread about it here https://el34world.com/Forum/index.php?topic=24246.0.

[jojokeo]

I came across a what I think is a capacitor across the input of the rectifier. Is this indeed a capacitor and if so what is it's purpose? Filtering? I have limited experience but I haven't seen a capacitor across the input of a rectifier.

Yes - the capacitors help filter out any possible rectifier switching noise that can be created. There's other things like transformer ringing and/or oscillation prevention as well.