APPLIES TO
Product: Projecta PM435 / PM235 Power Management System
Display Part Numbers: PMLCD and PMLCD-BT
Issue:
Display powers on, but one or more buttons do not respond.
Common Symptoms:
• One button stops responding while the other buttons continue working
• Any of the four buttons may be affected
• The affected button may be different between units
• A button may work initially and then stop responding after use
• Water pump or load buttons may not operate from the display
• Screen remains powered and displays system information normally
• Bluetooth app may still control the system correctly
• In some cases, all buttons may become unresponsive or the screen may appear frozen
FAQ-
My Projecta display screen is on, but one or more buttons are not working. What should I check first?
First, confirm that the display is powered and showing normal system information.
Please check:
• Is the screen lit up?
• Can you see battery level, time, system status, or other information?
• Does the screen flicker, dim, freeze, or remain stuck on one screen?
• Are all buttons unresponsive, or only one or two?
• Is the same button always affected?
• Does the button work initially and then stop responding after use?
If the screen remains powered but one or more buttons do not respond, the issue may be related to the display, keypad/button interface, connection, or internal circuitry.
Does a non-responsive button always mean the display is faulty?
No.
A non-responsive button does not always mean the display itself has failed.
Possible causes include:
• Loose connection behind the display
• Poor power supply
• Blown fuse
• Loose or damaged communication cable
• Software or firmware issue
• Button or keypad interface fault
• Internal display hardware fault
Basic checks should be completed before replacing the display.
What should I check if the screen is completely blank?
If the display does not turn on at all, check the power supply before assuming the display is faulty.
Please check:
• The caravan battery has sufficient charge
• The display power cable is connected correctly
• The relevant fuse is not blown
• The main Projecta power system is switched on
• There are no loose plugs or connections behind the display
If the screen remains blank after these checks, contact Projecta support, your dealer, or an authorised service provider for further assistance.
What should I check if the screen is powered but one or more buttons are not responding?
Try the following:
Step 1: Turn the system off, if safe to do so.
Step 2: Wait 1–2 minutes.
Step 3: Turn the system back on.
Step 4: Check whether the buttons respond after restarting.
Step 5: Check that the display cable is firmly connected behind the screen.
Step 6: Check for any loose, damaged, or bent connectors.
Step 7: Test whether the system can still be controlled using the Bluetooth app, if applicable.
Also note:
• Whether the same button always stops working
• Whether different buttons become unresponsive at different times
• Whether the button works initially and stops after repeated use
If the issue continues, the display may require further assessment or replacement.
What if only one of the four buttons stops working?
If only one button stops responding while the other buttons continue to operate, record which button is affected.
Please check:
• Whether the same button always fails
• Whether a different button fails each time
• Whether the button starts working again after restarting the system
• Whether the Bluetooth app can still perform the same function
If different buttons become unresponsive at different times, this may indicate an issue with the common keypad/button interface or internal display circuitry rather than one individual button.
Can I still use the system if the display buttons are not working?
In some cases, yes.
If the compatible Projecta Bluetooth app can still control the water pump and load functions, the main power management system may still be operating correctly.
For example:
• The app can turn the water pump on and off
• The app can control the load output
• The display remains powered
• System information is still shown on the display
• One or more physical buttons do not respond
In this situation, the issue is more likely related to the display, keypad/button interface, or internal display circuitry.
How do I test whether the Bluetooth app still works?
Open the compatible Projecta Bluetooth app and check whether you can control the system.
Test the following:
• Can you connect to the system?
• Can you turn the water pump on and off?
• Can you control the load output?
• Does the app display battery and system information?
If the app operates normally but one or more physical display buttons do not respond, this information is important for diagnosing the fault.
What does it mean if the app works but the display buttons do not?
If the Bluetooth app can control the pump and load correctly but one or more physical display buttons do not respond, this indicates that the main power management system and communication are likely operating correctly.
The fault is more likely associated with:
• The PMLCD or PMLCD-BT display
• Keypad/button interface
• Internal button circuitry
• Internal display hardware
• Display firmware or software
The display may require further assessment or replacement.
What if the faulty button changes?
Please note whether the same button is always affected or whether different buttons become unresponsive at different times.
Example:
• Pump button stops working on one occasion
• Load button stops working later
• Another button becomes unresponsive after further use
If the affected button changes, this can help identify a common issue with the keypad/button interface or internal display circuitry rather than a fault with one specific button.
Providing this information to Projecta support can assist with diagnosis.
What if neither the display buttons nor the Bluetooth app work?
If both the physical buttons and Bluetooth app control are not working, the issue may not be limited to the display.
Possible causes include:
• Main power system fault
• Battery or fuse issue
• Communication fault
• Incorrect or damaged wiring
• Main control board issue
• Bluetooth pairing or communication issue
• Display connection fault
Further diagnosis may be required before replacing the display.
What information is needed before further assessment or replacement?
To avoid delays, please provide:
• Display part number
• Display serial number
• Clear photo of the label on the back of the display
• Photo of the display powered on
• Short video showing the affected button or buttons not responding
• Confirmation of which buttons are affected
• Confirmation whether the same button always fails or whether the affected button changes
• Confirmation whether restarting restores button operation
• Confirmation whether the Bluetooth app can control the pump and load
• Proof of purchase, if requested
• Customer delivery details, if required
This information helps confirm the fault and ensures the correct replacement part is identified if replacement is required.
Where do I find the part number and serial number?
The part number and serial number are normally located on the label on the back of the display.
To locate them:
Step 1: Carefully remove the display from the wall mount.
Step 2: Do not pull hard on the wiring.
Step 3: Take a clear photo of the rear label.
Step 4: Make sure the part number and serial number are readable.
Step 5: Check that the wiring and connector are firmly fitted before reinstalling the display.
If the display is difficult to remove, contact your dealer or service provider for assistance.
Why do I need to provide a photo of the back of the display?
The rear label confirms the exact display model and serial number.
This is important because different Projecta displays may look similar but may not be interchangeable.
Providing the correct part number and serial number helps ensure:
• The correct display is identified
• Compatibility can be checked
• The correct replacement is supplied if required
• The affected production batch can be identified if further investigation is required
Should I replace the display immediately?
No. Basic troubleshooting should be completed first.
Before replacement, confirm:
• The display has power
• The screen is displaying system information normally
• The affected buttons remain unresponsive after restarting
• The wiring behind the display is secure
• The Bluetooth app has been tested, if available
• The affected button or buttons have been identified
• The part number and serial number have been recorded
• A photo or video of the fault has been taken
If these checks confirm that the main system is operating normally but one or more display buttons remain unresponsive, the display may require further assessment or replacement.
AFTER-HOURS TROUBLESHOOTING CHECKLIST
Step 1: Check Power
• Confirm the caravan battery has sufficient charge.
• Check the main power switch.
• Check the relevant fuses.
• Confirm the display is lighting up.
• Check whether normal battery and system information is visible.
Step 2: Identify the Button Fault
Check:
• Which button is not responding?
• Are the other buttons still working?
• Is the same button always affected?
• Does a different button stop working each time?
• Did the button work initially and then stop after use?
Make a note of what happens.
Step 3: Restart the System
• Turn the system off if safe to do so.
• Wait 1–2 minutes.
• Turn the system back on.
• Recheck all display buttons.
• Note whether the affected button starts working again after restart.
Step 4: Check the Display Connection
• Carefully remove the display from the wall mount.
• Check that the cable is firmly connected.
• Look for damaged, loose, or bent connectors.
• Do not pull on the wiring.
• Refit the display carefully.
Step 5: Test the Bluetooth App
If your system supports Bluetooth:
• Open the compatible Projecta Bluetooth app.
• Confirm whether the app connects.
• Try turning the water pump on and off.
• Try controlling the load output.
• Check whether battery and system information is displayed.
If the app works normally but the physical buttons do not, record this information.
Step 6: Take Photos and Video
Before contacting Projecta Tech support, take:
• A photo of the powered display
• A short video showing the affected button or buttons not responding
• A photo of the rear label showing the part number and serial number
• A photo of the display connector and wiring, if accessible
This information will help Projecta support diagnose the issue and determine the appropriate next step.