High Pitched Sound - A31

Message

jrv331 · #1 Post by **jrv331** » Thu Nov 08, 2007 3:46 pm

I'm having problems with my A31 not charging the battery and have run into a second problem. With the computer off, if I install the main or Ultrabay battery I can hear a faint high pitched sound coming from the left rear corner of the base. I took the system apart and took a picture of the area - its coming from the two small blocks by the processor. What are these, and are they replaceable? The sound stops if I plug the ac adapter in.john

Heres a pic http://profile.imageshack.us/user/jrv33 ... piclg3.jpg

Thanks
John

#2 Post by **rkawakami** » Thu Nov 08, 2007 4:03 pm

Looks like the same type of inductor that's on the T23 motherboard next to the CPU. You could try swapping them out with ones from mouser.com:

http://www.mouser.com/catalog/630/797.pdf

Probably one of the CDEP134 series at the top of that page. Look at the top line of characters on the inductor; should be something like "0R6NH". Then check the Sumida part number for the first three characters. It's soldered down to the motherboard in three spots.

On the T23 I'm typing on, it constantly "sings" but I just ignore it. It might be possible to stop the noise by:

- re-soldering it to the motherboard
- putting hot glue around the coil (limited space to do this)

BTW, your charging problem may be due to another inductor. That one probably looks like the CDRH104R series near the bottom of the mouser.com page.

edit: Corrected a bunch of typos!

jrv331 · #3 Post by **jrv331** » Thu Nov 08, 2007 4:17 pm

Thank you, I appreciate the help. Its amazing I search the net for hours and find nothing, you guys are a wealth of knowledge. One thing I forgot to mention in the original post, the battery seems to be discharging if in the computer when its off. Is this normal?It was 100% last night and 50% this morning.
Thanks again
John

#4 Post by **rkawakami** » Thu Nov 08, 2007 5:22 pm

Could be something on the motherboard draining the power from the battery or the battery can simply be getting too old. Was the system fully shut down? Or was it in hibernate mode? The reason I ask is that the T23 appears to drain the battery, very slightly, when in hibernate mode. Even if the A31 does the same in hibernate mode, it shouldn't cause half your battery's charge to disappear...

ref: http://forum.thinkpads.com/viewtopic.php?t=47929

jrv331 · #5 Post by **jrv331** » Thu Nov 08, 2007 6:09 pm

The system is completely shut off with ac adapter removed. The batteries are old, but I have another A31 that works fine and it doesnt make the sound or drain the batteries at all when off.

I just dont know what could be draining the power with the system off.

John

High Pitched Sound - A31

High Pitched Sound - A31

Who is online