Servicing Personal Computers, 3rd Edition

Miscellaneous faults

Fault diagnosis 141

Temperature-induced faults

Faults which do not appear until the equipment concerned reaches its normal working

temperature (this may typically take fifteen minutes or more) usually point to failure within an

integrated circuit. Often this results from an imperfect internal bond between the metal frame

that comprises the pins of the IC and the silicon chip itself.

In such cases, the fault can invariably be localized to a particular IC by judicious use of a

can of freezer spray. The spray nozzle is simply directed towards each suspect device in turn

and a short blast of spray released. Operation will normall ...