Ampeg svt 4 pro peak light, no output.

[wolfkeller]

Played this weekend. Last night and tonight. Used a 4 pro I picked up sounded great into 2 810s.

Today, soundcheck, no problem. Got ready to go on, speak light was on , no output. Turned of a couple times, it would go off and come on then go right back to red and off. This was like 2 min before show time.

I switched to by backup for the show.

I searched. Seems to be a common problem but that's all I got. I saw some suggest plugging a patch cable into the fx Jack's as a possible solution but that's it. I'll appreciate and input.

 

[wolfkeller]

Bump

 

[JimmyM]

In any amp with tubes, first thing I always suspect is one of the tubes. Did you do the chopstick test or swap each tube out one at a time with a known good one? And did you try the patch cable thing yet?

 

[wolfkeller]

In any amp with tubes, first thing I always suspect is one of the tubes. Did you do the chopstick test or swap each tube out one at a time with a known good one? And did you try the patch cable thing yet?

I set it up yesterday. At first the red light was on, then it went off and on a few times then stayed off. I did plug in a patch cable and left it in. It worked fine. So I am taking it to a tech I hope. 3 respected guys won't touch it as they say it's too hard to work on. Ofcourse it works fine at home.

 

[JimmyM]

I set it up yesterday. At first the red light was on, then it went off and on a few times then stayed off. I did plug in a patch cable and left it in. It worked fine. So I am taking it to a tech I hope. 3 respected guys won't touch it as they say it's too hard to work on. Ofcourse it works fine at home.

I would just try cleaning the FX loop jacks with Deoxit or plugging a cable in and out of the jacks several times rapidly, then try it. Sounds like there's corrosion in them.

 

[wolfkeller]

I would just try cleaning the FX loop jacks with Deoxit or plugging a cable in and out of the jacks several times rapidly, then try it. Sounds like there's corrosion in them.

I don't know of anywhere to get it locally. Electronics cleaner maybe? What if I leave the cable in?

 

[agedhorse]

Leaving the cable in is a good fix.

 

[Wasnex]

I set it up yesterday. At first the red light was on, then it went off and on a few times then stayed off. I did plug in a patch cable and left it in. It worked fine. So I am taking it to a tech I hope. 3 respected guys won't touch it as they say it's too hard to work on. Ofcourse it works fine at home.

I don't know if this amp is hard to work on, but fixing an intermittent problem that won't manifest for the tech is darn near impossible.

 

[BogeyBass]

Life without effect loops.
Ahhhh

 

[wolfkeller]

Well, I got it to a tech who is familiar with these. He doesn't seem to buy the Jack theory, we shall see for now.

Thanks very much to you guys for your time and insight, appreciated!

 

[JimmyM]

Life without effect loops.
Ahhhh

I have no use for them except to troubleshoot whether a problem is preamp or power amp related. And I use effects.

 

[wolfkeller]

Got it fixed. Tech said 1 problem was a bad connector to the main board. I think he said the ribbon connectors. Next, something about the mute button. From what I caught on the phone, it was somehow hijacking the output. I don't recall the last issue. So, $180 and back in black.