Lenovo ThinkPad 360 Hardware Maintenance Manual - Page 156

Symptom/Error One long beep followed by four short beeps each time the power switch is operated. (System cannot power-on due to low battery voltage.) One beep every second. (System is entering Suspend mode due to low battery voltage.) Two short beeps with error codes. Two short beeps with blank screen. FRU/Action 1. Connect the AC adapter or install a fully charged battery. 1. Connect the AC adapter or install a fully charged battery (allows system to suspend operation before changing the battery). 1. POST error. See "Numeric Error Codes" on page 142. 1. Top System Board. 2. Bottom System Board. No-Beep Symptoms Symptom/Error FRU/Action No beep, power-on indicator not on, and a blank LCD during POST. 1. Go to "Power Systems Checkout" on page 135. 2. Top System Board. 3. Power sources. No beep, power-on indicator on, and a blank LCD during POST. 1. Top System Board. 2. Bottom System Board. No beep, power-on indicator on, and a blinking cursor only during POST. 1. Top System Board. 2. Bottom System Board. No beep during POST but system runs correctly. 1. Turn the volume up. 2. Speaker. 3. Top System Board. LCD-Related (Video) Symptoms Note that LCD-related symptoms might be a result of software problems. Therefore, before working on hardware to correct video problems, make sure that the system has the latest versions of the video drivers installed. Systems that do not have the latest versions of video drivers might experience symptoms such as random extra pixels. 146 IBM Mobile Systems HMM