HP t628 t628 Thin Client - Page 54

Interpreting POST diagnostic front panel LEDs and audible codes This section covers the front panel LED codes as well as the audible codes that may occur before or during POST that do not necessarily have an error code or text message associated with them. WARNING! When the computer is plugged into an AC power source, voltage is always applied to the system board. To reduce the risk of personal injury from electrical shock and/or hot surfaces, be sure to disconnect the power cord from the wall outlet and allow the internal system components to cool before touching. NOTE: Recommended actions in the following table are listed in the order in which they should be performed. Not all diagnostic lights and audible codes are available on all models. Table B-3 Diagnostic front panel LEDs and audible codes Activity Beeps Possible Cause Recommended Action White Power LED On. None Computer on. None White Power LED flashes every two seconds. None Computer in Suspend to RAM mode (some models only) or normal Suspend mode. None required. Press any key or move the mouse to wake the computer. Red Power LED flashes two 2 times, once every second, followed by a two second pause. Beeps stop after fifth iteration but LEDs continue until problem is solved. Processor thermal 1. Ensure that the computer air vents are not protection activated: blocked and the processor cooling fan is A fan may be blocked or not plugged in and running, if equipped. turning. 2. Contact an authorized reseller or service provider. OR The heat sink/fan assembly is not properly attached to the processor. OR The unit has vents blocked or is in a location where the ambient temperature is too high. Red Power LED flashes four 4 times, once every second, followed by a two second pause. Beeps stop after fifth iteration but LEDs continue until problem is solved. Power failure (power supply 1. is overloaded). OR The incorrect external power supply adapter is being used on the unit. 2. 3. Check if a device is causing the problem by removing ALL attached devices. Power on the system. If the system enters the POST, then power off and replace one device at a time and repeat this procedure until failure occurs. Replace the device that is causing the failure. Continue adding devices one at a time to ensure all devices are functioning properly. Replace the power supply. Replace the system board. Red Power LED flashes five 5 times, once every second, followed by a two second pause. Beeps stop after fifth iteration but LEDs continue until problem is solved. Pre-video memory error. CAUTION: To avoid damage to the memory modules or the system board, you must unplug the computer power cord before attempting to reseat, install, or remove a memory module. 1. Reseat memory modules. 2. Replace memory modules one at a time to isolate the faulty module. 48 Appendix B Diagnostics and troubleshooting