“No Signal” is a message from the monitor about the selected input. It does not tell you whether the computer reached Windows or which component is responsible. Start with the external connection and record what is attached.

Trace one complete connection

Use the monitor menu to identify its selected input and match that to the physical socket. Note any dock, converter or adapter between the computer and display. With equipment switched off as appropriate, check accessible connections without forcing a connector or damaged latch.

If an alternative compatible cable or display is already available, change one part of the connection at a time. Record the result and restore the original arrangement before the next comparison. Buying several adapters before identifying the failed path can make the problem harder to follow.

Confirm which computer output is supported

A desktop may have ports on both its motherboard and an add-in graphics card. Which ports work depends on the processor, system design and configuration. Use the documentation for the actual computer rather than assuming that every motherboard port works or that it can never work alongside a graphics card.

Resolution and refresh rate depend on the display, computer output, cable and any adapter together. Apple makes this dependency explicit in its external-display guidance. A connector fitting physically does not prove the requested display mode is supported.

Keep startup and video observations separate

Record whether a manufacturer logo ever appears, whether an error or beep is present and whether the problem started after a move or update. A working monitor menu does not verify the entire input path. Keyboard lights and spinning fans do not establish a complete successful boot.

Do not reset the BIOS, change storage modes or flash firmware merely to investigate a blank monitor. If external checks do not identify the issue, provide the connection list and observations for assessment. Stop if there are signs of physical or electrical damage.

After repair, verify the actual input, intended resolution and refresh rate in the normal setup, including a dock if you normally use one.

Reference: Apple's guidance on external-display connections and supported modes.

For an AEPC repair assessment in East Auckland, call 027 908 8880 with your model, symptoms and backup status. Confirm the proposed work, any assessment fee and estimated timing before booking.