How to check a relay on a Fender Amp

[caesparza]

Hi guys.

I have a Fender Prosonic amp with a noise issue on the clean channel, according to the analysis made, the problem is located on the first relay. Is there a way of checking this kind of components with a mutlimeter?

Any help would be appreciated.

All the best.
CE

[nickb]

Relays seldom made a noise in and of themselves so it would not be the first place I'd be looking. What kind of noise? What analysis exactly? If a pop it might be DC where it shouldn't be. If a hiss you may have a bad component.

The relay can best be tested out of circuit using a power supply to operate the coil and using the continuity range on the meter to check the contacts. This will tell you if the contacts are working and low resistance.

PS: I just found your other thread. This only happens on the clean channel. I'd suspect C3 i.e. the cap that feeds the clean volume pot.

[Chuck H]

This only happens on the clean channel. I'd suspect C3 i.e. the cap that feeds the clean volume pot.

C3 and the clean volume pot would be the only component exclusive to the clean "channel". So there's that. But it's indicated that the problem manifests at the same volume regardless of volume pot setting. So that would put it ahead of the volume pot, wouldn't it?

[nickb]

But it's indicated that the problem manifests at the same volume regardless of volume pot setting. So that would put it ahead of the volume pot, wouldn't it?

That's new info to me. I guess it's in the other thread? A pity they got split if there was important info in there. If true then I would tend to agree. At a bit of a stretch it could be a bad ground on the pot, I suppose. The only way I can think of to reliably test a relay for noise would be the replace it.

[g1]

You can hardwire across the appropriate pins to bypass the relay. If the problem disappears, you know the noise was from the relay. If you still hear it, the problem is elsewhere.