ThinkWiki - User contributions [en]

Problem with high pitch noises

2008-05-04T22:08:44Z

Syscrash: new solution added (plug in usb mouse)

Information on strange high pitch, low volume noises emitted by ThinkPads.

==Problem description==
Even though ThinkPads are known as very silent notebooks, they tend to emit different, mostly high pitch noises in certain circumstances. The noises are of low volume and hence not realized by everyone or at least tolerated by most people. However, there are those with "bat like ears" that hear them and might be annoyed by that.

==Affected Models==
Noises have been experienced in the following situations:
{| border="1" cellspacing="0" cellpadding="2"
|-
! style="vertical-align:top;background-color:#DDDDDD;" | situation
! style="vertical-align:top;background-color:#DDDDDD;" | noise description
! style="vertical-align:top;background-color:#DDDDDD;" | affected models
|-
| style="vertical-align:top;" |
Plugged into AC / running at high CPU frequency
| style="vertical-align:top;" |
soft crackling, buzzing noise
| style="vertical-align:top;" |
*{{T41}}
**2379-DJU
|-
| style="vertical-align:top;" |
ThinkPad suspended to RAM
| style="vertical-align:top;" |
constant high pitch noise
| style="vertical-align:top;" |
*{{T42p}}
|-
| style="vertical-align:top;" |
ThinkPad connected to power and switched off, with battery fully charged
| style="vertical-align:top;" |
constant high pitch noise
| style="vertical-align:top;" |
*{{T41p}}
**2373-GHG
|-
| style="vertical-align:top;" |
moving windows or just the mouse in xorg
| style="vertical-align:top;" |
strange noise like a rapid series of very short high pitch noises adding to a constant kind of whistling (only as long as the movement goes)
| style="vertical-align:top;" |
*{{A21m}}
**2628
*{{T41p}}
**2373-GHG
*{{T60}}
|-
| style="vertical-align:top;" |
Thinkpad connected to power or working on battery, also when suspended to RAM
| style="vertical-align:top;" |
High pitch noise also when HD is powered down.
| style="vertical-align:top;" |
*{{T23}}
**2647-DG4
*{{X24}}
**2662-MWG
|-
| style="vertical-align:top;" |
Thinkpad connected to power battery charged less than 60%
| style="vertical-align:top;" |
High pitch noise till battery is charged more than 60%.
| style="vertical-align:top;" |
*{{T41p}}
**2373-GEG
|-
| style="vertical-align:top;" |
Constantly, if AC connected
| style="vertical-align:top;" |
High pitched, low volume constant noise.
| style="vertical-align:top;" |
*{{T40}}
**2373-88U
|-
| style="vertical-align:top;" |
When the CPU freq jumps up to 1Ghz or above, or when the laptop is in suspend mode
| style="vertical-align:top;" |
Constant high pitched
| style="vertical-align:top;" |
*{{R50}}
**1829-6DM
|-
| style="vertical-align:top;" |
(May come from harddisk.)
| style="vertical-align:top;" |
continuous, intermittent, low volume, high pitched
| style="vertical-align:top;" |
*{{600X}}
|-
| style="vertical-align:top;" |
ACPI puts the processor into the C3 or C4 power saving states (i.e., the system is idle).
| style="vertical-align:top;" |
High-pitched crackling noise.
| style="vertical-align:top;" |
*{{X41}}
*{{T43}}
**2686-DGU
*{{T43p}}
*{{T60}}
**2007-72U
*{{T21}}
*{{T20}}
**2648-46U
|-
| style="vertical-align:top;" |
Cpufreqd (or powernowd etc.) slows down the processor, for exemple at the end of an heavy task.
| style="vertical-align:top;" |
High-pitched crackling noise.
| style="vertical-align:top;" |
*{{T42}}
|-
| style="vertical-align:top;" |
When on battery
| style="vertical-align:top;" |
Noise level varies from inaudible to clearly audible, screeching sound, or sometimes beeping (when wifi is on).
| style="vertical-align:top;" |
*{{A21m}}
**2628
*{{R51}}
**EHG-1829
*{{R52}}
**1858-A11
**1846-B5G
*{{R60}}
**9461-DXG
**9462-77G
**9456-HTG
**9461-DXG
*{{R60e}}
**0657-A9G
**0657-3LG
*{{T43}}
**2686-DGU
**1871-4AG
*{{T60}}
**2007-72U
**1951-24G
**1951-24G
**2007-49G
**2007-FUG
*{{T60p}}
**2007-FBG
*{{T61}}
**7659-12G
*{{x60}}
*{{x31}}
**2673-CBU
*{{Z61m}}
**9450-3HG
**9452-128
**9452-W5Q
*{{Z61t}}
**9440-2QU

|-
| CPU is used much AND laptop is on AC power AND the TFT panel is enabled.
| Screetching high pitch noise, like a million crickets
|
* {{X41}}

|-
| Network is pluged in and networkload is ~100%.
| low volume highfreq. pitch noise from left speaker or cpu.
|
*{{Z60m}}, {{Z60t}}
*{{T40}}
*{{T43}}
**2687-DDU

|-
| Constant, but is louder when Tablet Pen is near screen, on battery power
| high pitch noise, screeching sounds *solved by "Media player paused" (see below) and also by BIOS versions 1.05 and later.
|
*{{X60_Tablet}}
**6366-4DU
|}

==Affected Operating Systems==
All, though Linux appears especially susceptible.

==Possible sources==

* '''CPU activity:''' On some models the noise is triggered by certain CPU power states or activity patterns (as proven [http://www.wisdom.weizmann.ac.il/~tromer/acoustic here]).
* '''Graphics processor:''' In some models from the T2x era, e.g. the {{T23}}, the problem was related to the graphics circuitry and occured especially or only while making use of DirectDraw functions. IBM was able to fix it through a BIOS upgrade.
* '''Hard disk:''' On some ThinkPads the processor and hard disk are adjacent and produce similar noise. For example, in the {{X41}} the sound generated by the hard disk is likely to be loudest at the vent.
* '''Gigabit Ethernet processor:''' In some models (e.g., {{T43}}) high ethernet activity causes a high pitch noise.

* '''Screen brightness:''' on an {{X31}}, a hissing sound is started whenever screen brightness is not full.

==Status==

The problem is highly specific to operating system, model and even individual machines. There is no universal solution, but on most machines one of the following will reduce or eliminate the noise (possibly at some cost in power consumption).

==Solutions for CPU-triggered noise==

===Limit ACPI CPU power states===

By default, the kernel supports up to eight ACPI CPU power saving states (C-states), called C1 through C8 (but the ThinkPad BIOS and hardware often offers (or remaps them to) only C1 to C4). Often only the extreme power saving modes C4 or C3 produce the noise, so the noise can be stopped by instructing the Linux ACPI code to use only lower modes. This has a cost, though: disabling C3 and C4 will make the CPU consume more power and reduce battery life.

To forbid the ACPI driver from using C4 (this fixed the problem with on some ThinkPad {{T43}}, {{T43p}} and {{T41}}):
* If the ACPI processor component is compiled as built-in (<tt>CONFIG_ACPI_PROCESSOR=y</tt>):
**Pass the {{bootparm|max_cstate|3}} kernel argument.
* If the ACPI processor component is loaded as a module (<tt>CONFIG_ACPI_PROCESSOR=m</tt> and <tt>processor</tt> shows in the output of {{cmdroot|lsmod}}), do either of:
** Pass the {{bootparm|processor.max_cstate|3}} kernel argument (this does not work in Ubuntu 5.10 with default kernel).
** Add <code>options processor max_cstate=3</code> to {{path|/etc/modprobe.conf}} (or {{path|/etc/modprobe.conf.local}}, or {{path|/etc/modprobe.d/...}}, depending on your system) (this does not work in Ubuntu 5.10 with default kernel).
** {{cmdroot|echo 3 > /sys/module/processor/parameters/max_cstate}} (this can be changed in runtime for experimentation). (If may need to be set again upon resume from suspend, e.g., in the wakeup script.)
** (On Ubuntu 5.10, the default kernel uses <code>processor</code> as a module. Unfortunately, the script loading it, {{path|/etc/init.d/acpid}}, ignores the <code>options processor max_cstate=3</code> setting in {{path|/etc/modprobe.d/<my file>}}. As a solution for this specific problem, add the line <code>echo 2 > /sys/module/processor/parameters/max_cstate</code> directly to {{path|/etc/init.d/acpid}}, at the end of the function <code>load_modules()</code>, immediately after the line <code>echo "$PRINTK" > /proc/sys/kernel/printk</code>.)
** On Gentoo: Configure your Thinkpad as described in the [http://www.gentoo.org/doc/en/power-management-guide.xml Power Management Guide]. Then as root create the files {{path|/etc/init.d/limit-sleep-states}} and {{path|/etc/conf.d/limit-sleep-states}} as below. After that just issue the command {{cmdroot|rc-update add limit-sleep-states default}} to limit the sleep states only when running on AC power, or {{cmdroot|rc-update add limit-sleep-states default battery}} to always limit the sleep states.
cat <<EOF > /etc/init.d/limit-sleep-states
#!/sbin/runscript

depend() {
need acpid
}

start() {
ebegin "Limiting CPU sleep state to C${LIMIT_CSTATE}"
echo $LIMIT_CSTATE > /sys/module/processor/parameters/max_cstate
eend $?
}

stop() {
ebegin "Removing CPU sleep state limit"
echo $REMOVE_CSTATE > /sys/module/processor/parameters/max_cstate
eend $?
}
EOF

cat <<EOF > /etc/conf.d/limit-sleep-states
# limit CPU sleep state to the following value (adjust accordingly)
LIMIT_CSTATE=3
# some value which is higher than all available sleep states
REMOVE_CSTATE=8
EOF

To also forbid the C3 state, replace "<tt>3</tt>" with "<tt>2</tt>" above (this fixed the problem on some ThinkPad {{X40}}, {{X41}}, {{X60}}, {{T60}}, {{T61}}, {{Z61t}} and {{R52}}, as well as on {{T20}} where C4 is not supported at all).

Note that these options affect power consumption when the CPU is idle. For example, here is the [[How to measure power consumption|measured power consumption]] on a ThinkPad {{T43}}:
* {{bootparm|processor.max_cstate|4}}: 15160mW (default, noisy)
* {{bootparm|processor.max_cstate|3}}: 15770mW (660mW higher, silent)
* {{bootparm|processor.max_cstate|2}}: 16100mW (2940mW higher, silent)

One can control how often Linux tries to enter the C3 state by using the {{bootparm|processor.bm_history|<bitmask>}} parameter on kernels with a scheduler frequency below 800Hz (and if you have noise problems, you really should not be running the kernel at 1000Hz...). Setting {{bootparm|processor.bm_history|0xFFFFFFFF}} will cause C3 to be entered less often. This will waste more power as the CPU won't do C3 or C4 as often, but at least it doesn't forbid C3 and C4 permanently, unlike {{bootparm|max_cstate|2}}.

See the [http://thinkwiki.org/wiki?title=Talk:Problem_with_high_pitch_noises discussion page] for further information and success reports.

*Jakob Schou Pedersen: Editing the file {{path|/etc/init.d/acpid}} as described above (the last solution) worked on my T43 :-)

===Turn off CPU power saving in the BIOS===

Go into the BIOS and turn off the power saving processor feature that puts it into idle mode. This should be somewhere under Config/Power - look for "CPU Power Management", the default being automatic. Set "CPU Power Management" to "Disabled" (This worked on a ThinkPad {{T43}}, {{T21}}, {{X60s}}, {{T60}} and {{Z61m}}). However, this also affects power consumption when the CPU is idle, it's similar to disabling the C4/C3 ACPI CPU power state. For example, on a Z61m 9450-3HG, a full charged battery with power management enabled in the BIOS provides the notebook with power for about 3.5h, if disabled, the battery-lifetime is only about 2h.

===Disable ACPI CPU power states===

Completely disable CPU ACPI power states. Discussion:

*From Martin Steigerwald: I made the observation that I get at least less high pitch noises on my {{T23}} when I do not use the two ACPI modules "processor" and "thermal" (depends on the first one). I have no clue, why. Anyone with similar experiences?
:Omar Yasin: I've got a {{R52}} and when I load the same ACPIO modules the high pitch noises are not as loud but I can still hear them.
*Kaspar Schleiser: On my {{T23}} the noise is less loud when setting max_cstate to 2, but to completely silence it, I have to set it to "1". Is that the same as removing the "processor"-module? "cat /proc/acpi/battery/BAT0/state" does not show increased power drain.
*Niko Ehrenfeuchter: I'm experiencing the same here on my {{X24}}. Removing the "processor" module also stops the pitch noise, which does ONLY occur when setting the CPU to maximum speed (using cpufreq). On low speed it's completely silent, even having loaded the processor module.

*Rolf Adelsberger: I can confirm this: the high pitch noise is only remarkable (at least with my ears ;-) ) if the processor speed is set to maximum frequency.

*Stefan Baums: My {{X41}} produced a high-pitched crackle from the processor vent on the left. Changing HZ did nothing, and the 'processor' module could not easily be removed from the system (Ubuntu 5.04). What solved the problem for me was adding {{bootparm|idle|halt}} to the boot command line. Unfortunately, this solution only lasts until the first hibernation or suspend - when the computer ({{X41}}) resumes, the high-pitched crackle is back.

* The {{bootparm|idle|halt}} solution combined with setting <code>#define HZ 100</code> in the kernel fixes the problem on a {{T43}}.

* jhatch: {{bootparm|idle|halt}} plus <code>#define HZ 100</code> also worked on my {{T43}}. It still reverts back to noisy after a suspend/resume though. This needs to be fixed...

===Use both C-States (sleep modes) and P-States (frequency scaling)===
*Max Gaukler: I had the problem with a "beeping" noise of my {{R60}} on battery. When using powertop I recognised that it went into C3 (deep sleep mode), but it was always running at the highest possible frequency. I followed the instructions in [[How_to_make_use_of_Dynamic_Frequency_Scaling|How to make use of Dynamic Frequency Scaling]] and the noise disappeared except for a short time during boot until frequency scaling has been loaded.

===Change the timer interrupt frequency===

Change the "HZ" kernel constants to alter the frequency of timer interrupts. Discussion:

{{NOTE|The timer interrupt frequency (HZ) in current Linux kernels is directly tied to the kernel task scheduler. Lower frequencies provide larger time-slices and thus also higher latencies (which may kill latency-sensitive applications like audio processing). 100Hz ended up as the recommended "server" setting (because it increases disk/CPU throughput in a latency-insensitive environment). Higher frequencies are better for latency-sensitive applications, and improve desktop responsivity at the cost of less processor throughput. 1000Hz ended up as the recommended "desktop" setting.}}

*Andreas Karnahl: i've read in several forums it has something to do with the "idle"-state (or "C3") of the processor. There is a frequency called "timer interrupt" (or so mething like that). Since kernel 2.6x it is set to 1000 Hz by default (compared to 100 Hz in Kernel 2.4x). The exact reason i don't know, but it is safe to change this frequency to 100 Hz in kernel 2.6x (by the way, windows up to XP uses 100 Hz by default).<br />Just do the following:<br />
: In {{path|[path to kernel-sources]/include/asm-i386/param.h}} find the line
:: <code>#define HZ 1000</code>
: and change the value of HZ to 100:
:: <code>#define HZ 100</code>
:Then recompile the kernel.<br />After i changed it on my ThinkPad {{A30}} (under SuSE 9.2 and 9.3) and recompiling the kernel the high pitch noise is gone away.

* Omar Yasin: Worked on my {{R52}}, thanks.

* [[User:Thinker|Thinker]]: In modern kernels this constant is in the kernel configuration {{kernelconf|CONFIG_HZ|Processor type and features||Timer Frequency|||||}}.

* [[User:sklnd|sklnd]]: As of 2.6.21, enabling a tickless kernel (CONFIG_NO_HZ) seems to fix the sound issue on the X60. This also has the added benefit of causing the kernel to wake up less, which will improve battery life.

===Prevent idling===

Indirectly avoid power saving states by making sure the CPU is rarely idle:

* Paul RIVIER: Here is a really simple workaround. C3 / C4 states are mainly called when the cpu freq is higher than required, for example if your cpufreqd is lazy to slow down the frequency but quick to raise it. That is why I use powernowd with the builtin "passive" mode, which is lazy for raising frequency, but quick to go back to the lowest. Now I don't hear them as often as before, as I avoid C3/C4 states at high frequency.

* The problem also occurs on my {{X41}} with 2.6.11. Setting up [[How to make use of Dynamic Frequency Scaling|frequency scaling]] with the <code>ondemand</code> governor makes things a lot better, as the processor does not stay with the maximum frequency when in idle mode. It can be still heard sometimes, though.

* On a {{T43}} the noise was gone after dropping cpufreqd and switching to the ondemand governor - maybe because of the high sampling rate? (used the default: 10ms)

===Change the processor voltage===

Reducing the processor voltage (when possible) may decrease or eliminate the noise. On one ThinkPad {{T43}}, [[Pentium M undervolting and underclocking|undervolting the Pentium M processor]] eliminated the high-pitched noise. Compared to the other solutions this has the benefit of lower power consumption, both due to the undervolting itself and because there is no need to forbid high APCI CPU power saving modes.

===Kernel BIOS options===

Adding acpi_sleep=s3_bios and pci=bios as boot parameters significantly reduced the pitch noise on a T61. Seems to be the best solution so far, without losing battery capacity. If ondemand governor is enabled as well, the noise is almost gone.--[[User:Mozz|Mozz]] 13:14, 18 January 2008 (CET)

==Solutions for screen brightness related sounds==

===Disable BIOS brightness control===

The sound starts when on batteries as the BIOS automatically reduces screen brightness. To disable this, simply switch Config>Display>Brightness from
Normal to High. See also [[User:Piccobello/Hissing sound on battery|here]].

==Other solutions==

===Disable UltraBay===
*Naheed Vora: My {{T41}} (2373-268) started to give high pitch noise ocassionally, when I upgraded to 2.6.11 kernel. I tried to unload lot of modules but finally figured out that disabling bay stops the noise. If you have [[ibm-acpi]], do (need a cleaner solution): {{cmduser|echo eject >/proc/acpi/ibm/bay}} .

===Disable IrDA===
*Mike Perry: I was able to cure an intermittent high-pitched whine on both my {{X24}} and {{X40}} by disabling the Infrared port.

===Disable the Linuxant Modem Driver===
*Joern Heissler: I made another experience. I played around with linuxant conexant [[Modem Devices|modem]] drivers. After loading them I got some noise on my {{T42p}}.

===Media Player paused===
*Eilif Muller: On my {{R52}} the high-pitched noises go away if I load XMMS, play something then pause it.
*Jacob: On my {{T43}} DGU it goes away if I open mplayerc.exe and press play then pause it. This is the high-pitched noise that only shows up when I'm on battery.
*butcom: On my {{X60 Tablet}}, this tip works in Windows as well with Media Player Classic or Windows Media Player. Just open either program, start playing any music file and pause it and the screeching noise stops.

''I'd guess that the above tip works as when xmms or similar is running, it is uncompressing compressed audio/video, which is a processor intensive action. Keeping this paused means that the app won't 'let go' of the processor, forcing it to stay up and running, which stops it entering the higher powersave modes.''

===nice yes===

Run the command:
{{cmduser|nice yes > /dev/null}}.

This is a good way to test whether the processor is causing the interference, since it forces the CPU to stay at full power. Of course, this will make your system get warm, and probably turn on the fan, as well as eating power.

===Upgrade BIOS===
On a ThinkPad {{X60s}}, [[BIOS_Upgrade|upgrading the BIOS]] to version 1.06 eliminated the high pitch noise when running on battery.

On a ThinkPad {{R60}}, [[BIOS_Upgrade|upgrading the BIOS]] to version 2.19 eliminated the voice also.

===Disable USB===
On one {{T43}} and one {{X60}}, (partially) disabling USB using {{cmdroot|rmmod uhci_hcd}} significantly reduced the noise. Also, on a {{T60}} this trick worked well, doing ''rmmod/modprobe'' twice wiped the noise permanently.

This is likely a CPU-induced noise case, as disabling USB UHCI will reduce a lot the amount of busmaster activity while the computer is idle, and thus has a direct effect on the need for ACPI C-state transitions from C3/C4 to C2 or lower states in a {{T43}} or {{X60}}.

*syscrash: Plugging in my USB mouse has completely solved the problem for me.

===Suspend USB===
*Stefan Ott: On my X41, the noise seems to have stopped since I enabled "USB selective suspend/resume and wakeup" (CONFIG_USB_SUSPEND).
*babrodtk: This approach worked with an R60 as well.

Talk:High-pitch noise from AC-Adapter

2007-08-08T14:28:17Z

Syscrash: /* I have it too, Thinkpad R61i */

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.

-- [[User:Hmh|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.

--[[User:Wohali|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 [[User:Wohali|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

-- [[User:Daw|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

Talk:High-pitch noise from AC-Adapter

2007-08-08T14:27:56Z

Syscrash: /* I have it too, Thinkpad R61i */

Talk:High-pitch noise from AC-Adapter

2007-08-07T23:46:56Z

Syscrash: I have it too, Thinkpad R61i

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.

-- [[User:Hmh|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.

--[[User:Wohali|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 [[User:Wohali|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

-- [[User:Daw|Daw]] 20:10, 31 July 2007 (UTC)

== I have it too, Thinkpad R61i ==

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).