The Chipmunk HDMI Tester is a simple tool to see if an HDMI port is working, and to give you feedback if the HDMI port is supplying an image without connecting a big HDMI monitor.
Works on all HDMI ports including on gaming consoles.
Has LEDs for the following:
1) Power - Lights up red if there is power in the HDMI port
2) 5 Volt - Indicates if the power is within specs, if so it lights continuous. Below 4.7 volts this LED is off. Above 5.4 volts it flashes.
3) EDID - This LED lights blue once the computer has read the (emulated) EDID ROM. This implies that the computer (or GPU) is running.
4) Data - 4 LEDs. One LED for each of the three data channels and one LED for the clock.
All LEDs are mirrored on the other side of the tester so you can always see them from either side.
Chipmunk universal HDMI Tester
Including shipping (world wide)
Using the Chipmunk universal HDMI Tester
To use the HDMI tester just plug it into any HDMI port of a device producing video. The tester is not meant for monitors/TVs. It will help your work if you always plug it in when working on any device that has an HDMI output. It only takes a 5 seconds to plug in and every once in a while it will help you a lot, especially if it shows you that something else is happening on the HDMI port from what you expected. At the very least it will work as the power light that so many modern devices lack.
The EDID LED and the Data LEDs work entirely independent.
The computer has three ways to 'see' the monitor.
1- The HPD line which is pulled high by the monitor, cable or in our case the tester.
2- By reading the EDID ROM in the monitor or on the tester. This also reveals the specifications/resolution of the screen to the computer.
3- Some computers monitor one of the diferencial data links to see if there actually is a device on the other end of the line.
When does the computer use the HDMI output?
Different laptops will behave different.
As far as we understand MacBooks (e.g. A1502) will use the HDMI port after booting into the OS. You can force the Mac to always use the HDMI port (i.e. also before and during boot) by either disconnecting the built in LCD or by closing the laptop lid.
Videos on Youtube featuring the Chipmunk universal HDMI Tester: