Troubleshooting

These iMacs are well over ten years old, so it’s normal to need a bit of troubleshooting after installing a DockLite. Find your symptom below and try the checks before getting in touch.

Blank screen Not detected by computer Blank screen Detected by computer Flashing screen Stays connected Flashing screen Connection drops in and out Interference Coloured pixels or artefacts Firmware error 513 Juicy-Link update fails

If your DockLite shipped after May 2024, check the diagnostic LEDs first. They usually show where the problem is. What the LEDs mean

Display problems

Try the checks in order. The first few are the quickest to rule out.

The screen is blank and the computer can’t see it
  1. Make sure the iMac is connected to power and the power button has been pressed.
  2. Plug the video cable directly into the computer, not through an adapter or hub.
  3. Verify the internal display connections.
  4. Plug a USB accessory into the DockLite’s USB ports to check whether they’re receiving power.
  5. Connect a device via the 3.5mm jack and check for audio from the internal speakers.
  6. Verify that the iMac’s power supply is working.
Likely cause

If the USB ports have no power and there’s no sound, the DockLite isn’t getting power. That’s usually a faulty iMac power supply, but the DockLite itself could also be defective.

Replacement power supplies are available from the Juicy Crumb online store.

The screen is blank but the computer can see it
  1. Plug the video cable directly into the computer, not through an adapter or hub.
  2. Verify the internal display and miniDP connections are installed correctly.
  3. Try a different host computer and miniDP cable if you have them.
  4. Re-install the iMac’s original logic board to test whether the backlight inverter and LCD backlight work.
Likely cause

A defective backlight inverter or LCD backlight in the iMac.

Replacement backlight inverters are available from the Juicy Crumb online store.

The screen flickers but stays connected
  1. Verify the internal backlight and LCD connections.
  2. Try a different miniDP cable on a different host computer if you have them.
Likely cause

A defective backlight inverter or LCD backlight that needs replacing.

Replacement backlight inverters are available from the Juicy Crumb online store.

The screen flickers and keeps disconnecting
  1. Plug the video cable directly into the computer, not through an adapter or hub.
  2. Verify the internal LCD and miniDP connections.
  3. Try a different miniDP cable on a different host computer if you have them.
Likely cause

If the USB ports drop out at the same time as the display, the power supply is likely defective.

Replacement power supplies are available from the Juicy Crumb online store.

Coloured pixels, lines or interference
  1. Remove any third-party adapters or video cables and use only the accessories provided in the box.
  2. Connect a different host computer and see if the issue remains.
  3. Re-seat the internal video connections and try again.
Likely cause

If the problem persists, the display wire loom, power supply or DockLite/DockPro may be defective.

Juicy-Link & firmware

Firmware update fails with error 513
  1. Open System Settings → Privacy & Security → Full Disk Access on your Mac.
  2. Turn on Full Disk Access for both Juicy-Link and Juicy Crumb Helper.
  3. Quit and restart Juicy-Link, then run the firmware update again.

Diagnostic LEDs

Every DockLite shipped since May 2024 has a row of diagnostic LEDs on the board. Each one lights up when its part of the board is working, so any LED that’s off shows you where to look.

DockLite diagnostic LED row: Crumb, VID_ON, 5V, 12V, 3.3V and Juicy, shown lit Crumb VID_ON 5V 12V 3.3V Juicy
With all six lit, the DockLite has power, working firmware and a video signal. Hover over or tap a card below to find that LED on the board.
Crumb

The microcontroller is working and the firmware is flashed correctly.

Off: microcontroller or firmware issue.
VID_ON

A valid video signal is detected from the connected computer.

Off: check the cable and host computer.
5V

The DockLite’s 5V voltage regulator is working.

Off: 5V regulator fault.
12V

The DockLite is receiving 12V and the power supply is active.

Off: check the power supply.
3.3V

The DockLite’s 3.3V voltage regulator is working.

Off: 3.3V regulator fault.
Juicy

The DockLite is receiving trickle power from the power supply.

Off: no standby power reaching the board.

Warranty & product info

Check your serial number

Enter the serial number from the label on your device to see its model and warranty cover.

Still having issues?

Tell us which checks you’ve tried and which LEDs are lit. It helps us work out what’s wrong much faster.

Contact customer support