Lenovo ThinkPad 370 Hardware Maintenance Manual - Page 428

Infrared Related Symptoms Symptom/Error FRU/Action Unable to communicate using the Infrared (IR) Port. 1. Make sure the setup for the IR is correct. 2. Make sure there are no fluorescent lights near the computer. The computer may receive electrical noise from the fluorescent light. 3. Run the advanced diagnostic test. If an error occurs and a FRU code is displayed, replace the parts shown by the FRU code. 4. For Model 755CV, if the remote control is enabled, the communication with the IR port is disabled. Run the Mind Path Presentation F/X program and set the infrared to OFF; then observe the symptom. Other Symptoms Symptom/Error Errors occur only when Port Replicator is used. PCMCIA slot pin is damaged. FRU/Action See "Port Replicator Checkout" in "Common Devices Checkout" section. PCMCIA Slots Assembly Note: If you cannot find a symptom or error in this list and the problem remains, see "Undetermined Problems" on page 419. Intermittent Problems Intermittent system hang problems can be caused by a variety of reasons that have nothing to do with a hardware defect such as: cosmic radiation, electrostatic discharge, or software errors. FRUs replacement should only be considered when a recurring problems exits. When analyzing the intermittent problem, do the following: 1. Run the advanced diagnostic test for the system board in loop mode at least 10 times. 2. If no error is detected, do not replace any FRUs. 418 IBM Mobile Systems HMM