Dell is contacting buyers of its PowerEdge 1650 servers because of a defect that can cause the systems to overheat, emit smoke and shut down.

The motherboards of all PowerEdge 1650 servers sold worldwide between January and early May last year could be defective and should be replaced, said Dell spokesman Bruce Anderson.

"The inductor on the motherboard can overheat and can cause a small amount of smoke to emit," he said. When the overheating occurs, the server shuts down. "There is no safety issue," Anderson said. The inductor is used to control voltage, he said.

Dell started contacting customers late last year after users notified the vendor of the problem and determined the issue in its test environment, Anderson said.

The Dell PowerEdge 1650 is a rack server meant for use in data centers. The product was introduced in February of 2002 and succeeded by the PowerEdge 1750 in mid-2003. The motherboard in the PowerEdge 1650 was designed by Dell, according to Anderson.

Anderson declined to specify how many PowerEdge 1650 servers have the problem or how many Dell has sold overall. He also would not say who is to blame for the issue or how much it is costing Dell to fix it.

As a direct seller, Dell knows who buys its products. Dell will contact owners of affected systems and arrange to have the motherboard replaced, Anderson said.