MY Fender Passport P250 went into protect mode. I changed the FUSE at the power supply with a new fuse. Still it is in Protect mode. How to fix this

BAD NEG. 15V REGULATOR AND RELATED CAPS IN POWER SUPPLY.CAUSES UNIT TO GO INTO PROTECT. main supply caps and power transformer is gone. possible you'll have to trash. good success, meder's tv service

Likely an overload failure caused the protect light to come on, and then the fuse blew so all power is off... Do NOT replace the fuse as you will LIKELY do additional damage to components. Take unit in for repair immediately.
Note: These units are really hard to work on due to the way they are packaged.

Either one of the amps or the power supply has blown. The protect light means the power supply has been shut down due to overcurrent. Take unit in for repair. These are hard to work on due to packaging.

Likely there is either a failure in one of the power amps or the power supply. The protect means excess current is being sensed.

You need to take in for repair... these are really hard to work on due to the packaging.

There is a problem with the internal amp itself. These are extremely difficult to access. Contact Fender for a local authorized service center.

Dan

This indicates either one or more of the amps have a failure OR the power supply is being overloaded which is usually also caused by failure in the amplifier.

Occasionally a power supply failure causes this problem as well.

Due to the way these are packaged, they are a real pain to work on for repairing.

I have one that has done the same. It is the next smaller size. The power supply fried a toroidal inductor in mine. Frankly, these things are a major pain to work on. You have to usually remove the front panel before you can remove the back power supply and power amp section.

If you have warranty coverage USE IT !!!

The protect feature in mine monitors the power supply load and shuts down the supply if it senses overload. They are hard to work on as you have to bypass the protect to troubleshoot and get to the root cause.

Use the old light bulb in series trick to limit the current.

I had a problem like this that was caused by a short between the two windings of the toroid in the power supply.

The solder blob is probably supposed to be there as there are numerous common ground points.

This unit is miserable to work on....

The protect circuit is activated by a current sensing transformer in the *input* of the power supply. If any of the subassemblies of the unit (or all of them in combination) draw excess current then the protect light will illuminate and the power supply shut down to prevent any damage to the system.

The circuitry in the power supply is fairly robust as well as fuse protected so it is unlikely that the power supply itself has failed. More than likely one of your output power transistors has been shorted and it is easy to check this yourself if you are interested in doing so.

Furthermore if you follow a few *simple* precautions you can do this safely and confidently.

Post again on this thread if you are interested and I will spew the details.

-BK