IT giant Cisco has warned customers that certain blade servers that it sells as part of Unified Computing System data centre platform are prone to overheating and emitting a "short flash" in the event of a transistor failure.

"A failure has been observed where a MOSFET [metal–oxide–semiconductor field-effect transistor] power transistor failed in a manner that caused the MOSFET to overheat and emit a flash before failing," the company revealed in a field notice.

The company had previously advised the customers upgrade to latest version of its UCS Blade Management Controller firmware, but it has since been shown that this does not protect against all MOSFET failures.

It has therefore launched a hardware replacement programme for existing customers.  "Cisco is directly contacting UCS B440 Blade Server customers and will replace UCS B440 Blade Servers currently deployed at customer sites," the company said.

The field notice contains information on how organisations can identify whether their hardware might be affected.

When Cisco launched UCS in 2009, it was a bold step by the networking equipment vendor into data centre infrastructure. After the company’s most recent financial quarter, Cisco CEO John Chamber told investment analysts that UCS is selling at an annualised run rate of $1 billion, having grown by 116% year-on-year.

"Results in this area have been particularly outstanding, given that we are taking on the big competitors in the data centre," he said.