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

I have the high-pitched whine

My T60 PS is labelled P/N 92P1105, FRU P/N 42T5000, and is labelled "11S92P1105Z1ZBW96AV0R9 Rev 05." The whine the device makes is around 8kHz, and drops to about 800Hz when there is no load on the device. Unplugging the device from AC, it takes about 5s before the whine goes away. The noise is quiet enough that in a typical office environment you don't hear it, but in a quiet hotel room at night it's unbearable, especially for my "bat-like" hearing.

I've tried running the PS off of a UPS and 2 AC sources, and they're not the source of the whine. In other words, it's not the AC that causes the whine, it's something wrong with the PS.

I'll be contacting Lenovo to see if I can get a replacement mailed out, and if one is, I'll post here.

--Wohali 16:16, 16 December 2006 (CET)

I have the high-pitched whine too

• X60 Tablet (6366L6U), purchased a few days ago from CDW
• AC Adapter
  • P/N 92P1156
  • FRU P/N 92P1155
  • 11S92P1156Z1ZBGF76N78X Rev:D

Behavior sounds equivalent to Wohali's description.

-- charkins Mon Jul 9 14:37:31 CDT 2007

I have the high-pitched whine too

• X61 (type 7675-CTO), arrived a few days ago from Lenovo
• AC adapter:
  • P/N 92P1156
  • FRU P/N: 92P1155
  • 11S92P1156Z1ZBGF776ALF Rev:E
  • says it is rated for 65W 20V

-- Daw 20:10, 31 July 2007 (UTC)

I have it too, Thinkpad R61i

P/N 92P1156 FRU P/N 92P1155 11S92P1156Z1ZBGF7764XG Rev:E

I recently purchased an R61i (I received it yesterday!) and noticed the high-pitched noise. I called Lenovo and they said they'd ship me a new one (and I have to send the old one back; they're arranging for it).

-- syscrash Wed Aug 8 10:21:11 EDT 2007

Another R61i

I guess I've got the same high-ptiched whine on my R61i as well. I've been trying to pinpoint the device, and I never realized it was the AC adapter (it's not the adapter itself whining, but something on the base of the laptop). I've been playing around with my kernel, wondering if there was a module that accessing some hardware would initiate the whine or not. So far, the main culprit I've found is loading the UHCI module (USB 1.1 driver) really made it scream when I first got it. Then it seems like it happens whenever the harddrive is really busy (Gentoo + compiling == a lot of access).

Oddly enough, for me, the sound comes and goes, so I haven't been able to pinpoint the source. Crappy power input could be the reason, but I'm not sure. Sometimes I get a whine even when it's unplugged. So, in summary, I get whines from a number of places for a number of reasons, but I'm not sure why. USB and lots of hd access seem to be the main reasons. So far the best solution I've found is to just run cpufrequtils with ondemand or powersave governors to get it to not speed up unless I have to.

SDibb 19:58, 23 December 2007 (UTC)