White screen after reverse engaged.

All I can think of is either white balance, or exposure compensation. Have either of these deviated from the norm ?

many components can work when cool but after heating up lose conductivity, could be many different components that might cause this, needs a professional to track it down

Reverse sensor wire not connected correctly

I'm assuming this is a DVD player or at least contains a video screen. The message you are seeing sounds like the rear camera input has been activated. They give this alert to inform drivers that the view through the rear cam may be reversed. Most cameras have a switch setting to allow this adjustment.

If you do not have a rear camera installed, then it sounds to me like the rear camera trigger has been improperly connected. This is a wire that when it sees a 12-volt signal, activate the rear cam input on the radio. If you do not have a rear camera, this wire should not be connected. You did not give a make/model so I cannot begin to guess the wire color, but look for a wire that is not either black, red, yellow, white, gray, green, violet, or blue (with or without stripes). There is no standard color for this wire. Some Alpine units use orange/white, but on most radios, this is a dimmer wire. Pioneer and Kenwood often use a light purple or purple/white.

Find out what wire is for reverse camera and disconnect it.

The purple and white wire connects to the vehicles reverse wire. This will switch the picture on the screen to the rear camera when backing up.

looks like you need a new screen

it depends if it is auto or manual. There is a nuetral saftey switch on the auto-located on the manual valve arm(the piece that the linkage from the shifter connects to at the trans.) On the manual trans. there will be a 2 pole switch on the top shift plate that is for reverse only. The starting(clutch engagement switch)is located at the clutch pedal-2 seperate switches. First check for power at the back up light bulb connecter with reverse engaged(may have power at all times when key is on). Then check for ground when reverse is engaged-from bulb connecter to ground) with reverse engaged. The switch will just provide the ground when reverse is engaged. The power comes from an alternate source. Most likley a switch issue but at least this way you can be sure.

a defective nuetral safety/ backup light switch on the transmission will cause this, they can stick. Cost qabout $40, here is a part number and picture.
STANDARD MOTOR PRODUCTS Part # NS122

Either your LCD is damaged or the cable connecting it to the rest of the camera is loose. I would suggest taking it to be repaired.

Check to see if the wiring at the fan is reversed - perhaps the neutral (typically white) & hot (typically black or red) are swapped.

If this is not the case, check to see if the neutral & hot are switched for the entire circuit.