An intermittent problem can show many different symptoms, so it may be difficult for you to determine thereal cause without completely analyzing the failure. To help with this analysis, you should determine asmany symptoms as possible.v The complete SRC and unit reference code (URC) information is necessary to determine the exactfailing area and the probable cause.v Product Activity Log information can provide time and device relationships.v Information on environmental conditions when the failure occurred can be helpful (for example, anelectrical storm occurring when the failure happened).Note: If you suspect that an intermittent problem is occurring, increase the log sizes to the largest sizespossible. Select the Product activity log option on the Start a Service Tool display (see ″Product ActivityLog″ in the iSeries Service Functions information).Types of intermittent problemsThere are four major types of intermittent problems:v Code (PTFs)– Licensed Internal Code– OS/400 (operating system)– Licensed program products– Other application softwarev Configuration– Non-supported hardware that is used on the system– Non-supported system configurations– Non-supported communication networks– Model and feature upgrades that are not performed correctly– Moving of down-level hardware from other systems to the iSeries server– Incorrectly configured or incorrectly cabled devicesv Environment– Power line disturbance-for example, reduced voltage (sag), a pulse, a surge, or total loss of voltageon the incoming ac voltage line– Power line transient-for example, a lightning strike– Electrical noise (constant or intermittent)– Defective grounding or a ground potential difference– Mechanical vibrationv Intermittent hardware failureGeneral intermittent problem checklistFor use by authorized service providers.The following steps have been successful in correcting intermittent problems on the iSeries server.Performing these steps removes the known causes of most intermittent problems. Therefore, it is importantthat you perform all of these steps. Some customers have a high availability requirement for the iSeriesserver (such as 24 hours a day, 7 days a week). It is very important that you perform all the steps in thischecklist to ensure that the system can meet this availability requirement.1. Discuss the problem with the customer. Look for the following symptoms:v An SRC or reference code that goes away when you power off the system, then power on thesystem.v Repeated failure patterns that you cannot explain. For example, the problem occurs at the sametime of day or on the same day of the week. Look for some type of pattern.Analyze hardware problems 13
