Fender Rumble 500

[Pinned]

Hello, I am trying to figure out my new to me fender rumble 500 amp and was hoping you guys could help. I get nothing out of the speakers when using the input jack but if i use the effects line in I get sound [low volume and not eq controllable or volume controllable]. If i add a boosted signal to the effects loop it cranks pretty good. I get no response from the instrument jack whatsoever. The head phone jack gives the same response if using effects loop only, nothing from instrument input jack. Lights all come on, heat sink fan runs, all seems normal but no sound. I looked at the boards and nothing looks cooked or out of the ordinary, any ideas? FYI I bought the amp in this condition so I have no idea of what caused its failure. Thanks in advance for any help.

Jim

 

[JonSnell Electronic]

Which model? There are at least 3, all different.

 

[Pinned]

The latest version I believe..date code is late 2015 so I think V3

 

[JonSnell Electronic]

Possible power supply failure.
Check R400 and R401.
Follow the signal through backwards from the effects towards the input.

 

[Pinned]

What should i be reading, will it be in volts[power on] or am I just looking for ohms/continuity?

 

[Tarzan]

Hi,
I do not have a schematic but I found these few lines some time ago. Maybe they can help.
Give it a try...

 

[cbdb]

Check the input jack and its solder connection.

 

[Pinned]

Will do thank you

 

[Pinned]

Tarzan I am not sure what lines youre refering to, forgive my ignorance

 

[JonSnell Electronic]

You are looking for about 15volts on each, + & - supplies to the ic's.
Pin 4 of the chips should have -ve 15 volts on them and pin 8 +ve 15 volts, if you cannot locate those resistors.