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Cobra SPX 5300 Troubleshooting

The Cobra SPX 5300 is a radar laser detector developed by Cobra Electronics Corporation. Released in 2013, this base model is part of the SPX series.

Detector Won't Turn On

The detector will not power on regardless of what I do.

Faulty Power Cord

The detector is not wireless and must be plugged into a power source. If the device will not turn on, your power cord connecting the device to your cigarette lighter outlet may be faulty. Pull the cord out and reinsert it multiple times. If there is still no response, you should check the cord in a different outlet. If there is still no response, you may want to buy a new power cord.

Faulty Cigarette Lighter Fuse

If the power cord was not the issue, the cigarette lighter fuse may be. To check this, unscrew the tip of the cigarette lighter plug and make sure that all of the fuses are connected properly. If they are connected, test your device’s power cord in a different cigarette lighter within the vehicle to ensure that the power cord is not the problem. If they are not connected, the fuses may need to be replaced or repaired.

Obstructed 12V DC Power Jack

This is the point of connection for the charging port. Check the jack for dirt, lint, and damaged pins. Very carefully, use a toothpick or soft toothbrush to clear the obstruction. If the jack has been cleaned and your power cord is functional, the charge connector may be faulty. You will want to replace the detector.

Detector Issuing False Alerts

I'm getting alerts and there are no police cars around.

Incorrect Settings and Channels

The factory setting for the device is Highway Mode. If you change your setting to City Mode, the device picks up only stronger signals, like police radar, and reduces conflicting signals, like microwave towers, which lead to false alerts. The POP mode sensor is also very sensitive, so limiting your use to highway and rural driving should reduce the number of false alerts.

Detector Not Issuing Alerts

I’m not getting any alerts at all.


If you are not receiving any alerts, the mute button might be pressed. Check in the Cobra SPX 5300 Radar Detector that the middle left button that says “MUTE” is not pressed, otherwise all the alerts will be shut off. If it is pressed, just press it again to activate the alert sounds. If you have tried pressing the mute button to take off the mute function and the device is still not issuing alerts, the button itself may be faulty. You will want to replace it.

Faulty Audio Dial

If the mute button is not pressed and there are still no alerts issued from the Cobra SPX 5300 Radar Detector, the audio dial might be faulty. You will want to replace it.

Incorrect Position

The Cobra SPX 5300 is very sensitive to positioning within the car. In order for the device to receive a strong signal from radars, it must be level on the windshield and have an unobstructed view. If the device is not positioned in that way, it may not receive any signals.

Dim Display

The screen is difficult for me to read.

Incorrect Settings

The device's factory setting is the brightest display. If you have accidentally pressed a button or adjusted the settings, it would have affected the backlighting. If you have pressed the Dim button to change the VG-2 and Spectre I & IV+ alerts, then the display setting might have been changed. You can cycle through the brightness settings by pressing and quickly releasing the Dim button. When you hear two beeps after pressing the Dim button, the display has been returned to full brightness.

Faulty Screen

If you changed the brightness back to the factory setting and there is still no visual display, your screen may be faulty. You will want to replace the screen.


Arched after few months use smoke came from inside the detector. . This is the second one. Same model. Same problem. Unbelievable.

Michael - Reply

It comes on all the buttons work and the audio dial works the mute is off but still no alerts

John - Reply

I'm having the same issue

Colton shelton -

I think they are China made crap - my display is now unreadable - on maximum brightness - & i used the screen saver function & took it off the windshield to keep it out of heat & bright sunlight when the vehicle was parked. Mine is the SPX 7800 BT model, not a cheap one… Blue tooth conection - that's now deciding to play up to….

Next time i buy Bell product….

Fot - Reply

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