Talk:High-pitch noise from AC-Adapter

What is the part number and lot number (not the serial number) for the AC adapters exibiting the problem?

FYI, high pitch noises from AC converters usually mean a protection component is either vibrating (may or may not be dangerous, depends on how well built the AC adaptor was), or that something is leaking electricity (dangerous for your ThinkPad).

Plug the adaptor in a high-quality voltage regulator. Does the noise go away? What about plugging it at another part of the AC grid (like at work if the noise shows up at home and you leave at least 5km away from work)?

If the noise goes away, that means your AC is bad and some protection circuitry in the AC adaptor is making noise when it gets activated. You may still try to replace it, but you better get some high-grade AC voltage regulators and grounding to fix the AC you use.

Anyway, if the noise levels are too high to tolerate, call Lenovo and bitch like hell that you want a replacement and offer to send them the old AC adaptor back for quality control and inspection. It is likely that a batch of AC adaptors has this problem, but not all.

-- hmh 2006-07-19 13:31 UTC