Ampeg PF 500 Fault Light

[Ian_H]

Hey everyone!

Im sure this has been covered on this forum, but my PF 500 (solid state) fault light is on and no sound. I know this is a common issue with these amps. I opened it up and found a semiconductor or something of that nature burnt up so hoping that is the issue. i'll have an image below (sorry its so small, I tried using a magnifying glass to enlarge). Anyway, does anyone know exactly which part this is? Its so small and I cant read any text on it. It is on the schematic as R101. Images attached. Im assuming its a semiconductor or inductor etc..

Any advice would be greatly appreciated!

 

[agedhorse]

It's a resistor, one of probably many parts that have failed. Generally the damage is on the inside of the part, and when there is a failure in this type of circuit there is usually more damage than you can see.

 

[seamonkey]

You could probably search the "R" number on the schematic
[Invalid or Expired Link Removed]

It's a resistor that costs $.25 but then what are you going to do?
It's not going to be an easy repair. Looks like the traced burned up, and whatever cause the resistor and trace to burn is elsewhere in the circuit.

Fullcompass.com sells board replacements but it will be much more than $.25 and probably not much less than what a whole replacement head would cost.

Best of luck.

 

[6thplanet]

Well that's an easy fix, Mesa sells the replacement part. You'll be able to install it yourself, too! Part#TT-800

 

[Ian_H]

It's a resistor, one of probably many parts that have failed. Generally the damage is on the inside of the part, and when there is a failure in this type of circuit there is usually more damage than you can see.

Thanks for your input! Yea at this point its more of a project since I have a few other amps available for gigs. But keep any other info coming!

Thanks again!

 

[Ian_H]

You could probably search the "R" number on the schematic
[Invalid or Expired Link Removed]

It's a resistor that costs $.25 but then what are you going to do?
It's not going to be an easy repair. Looks like the traced burned up, and whatever cause the resistor and trace to burn is elsewhere in the circuit.

Fullcompass.com sells board replacements but it will be much more than $.25 and probably not much less than what a whole replacement head would cost.

Best of luck.

Thanks I am checking it out. Appreciate the help!

 

[agedhorse]

Thanks for your input! Yea at this point its more of a project since I have a few other amps available for gigs. But keep any other info coming!

Thanks again!

Even with my knowledge and resources, it's not something that would find easily or economically repairable. Fortunately a replacement PCB assembly is available, which is a MUCH more practical approach.

 

[DW1969]

Mine is in for repair for fault light and no sound. When I dropped it off they said they replace the whole board and said it might not be worth fixing.

I called yesterday and they said it was a simple fix and they did not have to replace the board.

 

[agedhorse]

Mine is in for repair for fault light and no sound. When I dropped it off they said they replace the whole board and said it might not be worth fixing.

you are very lucky.

I called yesterday and they said it was a simple fix and they did not have to replace the board.