Indicator function of the diagnostic card:
CLK: No matter ISA or PCI, as long as there is a empty board (no CPU etc.), the light should be on when power on, otherwise, the CLK signal is failure
BIOS: Mothermoard running, the light will fash while there is a reading operation on the BIOS.
IRDY: The light will flash when having a IRDR signal, otherwise, it will not lignt on.
OSC: Empty board powered on, the light will be constant on, when there is the ISA slot have main vibration signal, otherwise, failure of oscillation.
FRAME: The light will flash when there is circular frame signal. Light will constant on in peacetime
RST: Reset
RESET: power on or press the RESET switch, the light will be on for half second and then be off. Because, if light is not off, the reset pin on motherboard connected to the acceleration switch or the reset circuit broke down.
12V: Empty board powered on, the light should be constant on, otherwise the voltage or motherboard has a short circuit.
12V: Do ditto
5V: Do ditto
5V: Do ditto (only for ISA slot).
3V3: This 3.3V voltage is unique for PCI slot. Empty board powered on, the light should be constant on. Some of PCI slot motherboard has not this voltage, the light should be off.

Specifications:
Usage: Maintenance tools for computer motherboard
Specifications: All produced by patch components, do not hurt your hands, LCD characters display
Color: Shown as the picture
Package weight: 48g

Package Include:
1 x Diagnostic Card
1 x English User Manual