Ampeg PF-50T Fault Code

[akrachanko]

So, my Ampeg PF-50T amp has been giving me a fault code on cold power up (red and purple lights alternating). If I let the amp sit in this state for about a minute (in standby) then power it off and on again, the amp no longer gives a fault code and operates normally. Has anyone run into a similar issue, or have any ideas what it may be? I'm taking it to an Ampeg Service Center tomorrow, but I just figured I'd ask to see if anyone knew.

 

[JimmyM]

Just a guess here, but I think you have a tube on the way out. Differences in operation with cold and warm make me think it's tube related.

 

[akrachanko]

Just a guess here, but I think you have a tube on the way out. Differences in operation with cold and warm make me think it's tube related.

Thanks Jimmy. That's my suspicion too. I would honestly be happy if it was just a tube, because that's an easy fix. I'm just hoping it's not something more serious.

 

[Camaro69]

So, my Ampeg PF-50T amp has been giving me a fault code on cold power up (red and purple lights alternating). If I let the amp sit in this state for about a minute (in standby) then power it off and on again, the amp no longer gives a fault code and operates normally. Has anyone run into a similar issue, or have any ideas what it may be? I'm taking it to an Ampeg Service Center tomorrow, but I just figured I'd ask to see if anyone knew.

Any update on this?

 

[BogeyBass]

Red purple flashing is fault code and needs to be serviced.

low/high voltage or low/high current

a bad tube could trigger it if there was a heater to cathode short on a preamp tube
and yes a heater cathode short can be intermittent or change with cold/ warm cycles

aside from many other things that could cause a fault code
new tube would solve the problem if its a tube issue

 

[akrachanko]

Any update on this?

It was tubes going bad. 4 of the 5 tested weak, so the private party I bought it used from must have had a lot of hours on it. A full retube did the trick!

 

[JimmyM]

It was tubes going bad. 4 of the 5 tested weak, so the private party I bought it used from must have had a lot of hours on it. A full retube did the trick!

A lot of fairly hard hours on it, sounds like. Glad you got it sorted.

 

[beans-on-toast]

It was tubes going bad. 4 of the 5 tested weak, so the private party I bought it used from must have had a lot of hours on it. A full retube did the trick!

Good to hear that it worked out.

Sometimes when people are selling amps they populate it with all their worn out tubes before shipping it out. Part of the cost of buying a used amp.

 

[Camaro69]

Good to hear that it worked out.

Sometimes when people are selling amps they populate it with all their worn out tubes before shipping it out. Part of the cost of buying a used amp.

Nah, nobody would do that, would they? Or put “shipper strings” on a bass before sending it?