February 7, 2008

Panasonic CF-Y4 laptop disassembly

Filed under: Hardware,Misc — Nate Lawson @ 6:00 am

I’m a big fan of the lightweight Panasonic ultraportable laptops.  The R-series is small but still usable.  The Y-series offers a full 1400×1050 screen, built-in DVD-RW drive, and long battery life in a 3 pound package.  As a FreeBSD developer, I also find the BIOS in the Panasonic and Lenovo/IBM laptops are mostly compliant, meaning suspend/resume and power management work fine.

Recently, I upgraded the hard drive on my CF-Y4.  I found that these disassembly instructions (another good source) for the CF-Y2 are mostly accurate.  However, there are a few caveats I wanted to note for others with the R/W/T/Y series laptops.

First, all the notes about 3.3 volt logic versus 5 volt logic for the hard drive no longer apply.  The Toshiba hard drive that came in my Y4 uses 5 volt logic, along with 5 volt motor supply.  In fact, the pins are tied together internally.  It was straightforward to swap in a WD 250 GB drive with no clipping pins necessary.  This may apply to the newer R-series as well, though I haven’t verified it.  If in doubt, use an ohmmeter to verify no resistance between pins 41 and 42 on the stock hard drive.

Next, heed the warnings about stripping the top two large hinge screws.  They screw directly into plastic, while the other two hinge screws have a steel sleeve.  Use a good jeweler’s screwdriver for the small screws.  You don’t need to remove the two screws that hold the VGA connector to the case.

When removing the keyboard, pry smoothly in multiple places but don’t be afraid to put a little effort into it.  The glue used to hold it down is surprisingly strong.  Be sure you removed all the small screws from the bottom, of course, otherwise it won’t pop out.

Be sure to clean the CPU’s heat sink connection carefully and use some good thermal paste when reassembling.  These laptops have no fan (awesome!) but that means it’s critical to make a good connection between the CPU and the keyboard heat sink area.  Also, don’t forget the GPU, which sinks heat through the bottom of the motherboard.  I cut a small piece of plastic to use as a spreader to eliminate any bubbles.  I also put a thin amount of paste along other parts of the internal skeleton where it touches the keyboard.  Once you reassemble the case, monitor the system temperature for a while to be sure you didn’t make a mistake.  I found my temperature actually dropped compared to the factory thermal paste.


  1. Does anyone knows (Nate?…) if the Y4 can be upgraded to 2GB RAM instead of the limited 1GB it now has? I am actually using XP on it (yes, I do have SUSE on externally bootable drive for real work). If so, any recommendation for compatible memory?

    Thanks for the excellent instructions!! I will buy the same drive – BTW, any glitches with it, since the reviews are mixed?

    Comment by arnon chait — April 14, 2008 @ 11:48 am

  2. No problems with the hard drive yet. It’s a little louder than the old Toshiba but not too loud. I have a feeling from the reviews that some bad batches may have gone out, so you’ll either get one that works or fails pretty quickly it seems. I think these days even reliable manufacturers have that issue.

    The max it can be upgraded easily to is 1.5 GB. It has 512 MB soldered onto the motherboard and a socket that takes either a 512 or 1 GB upgrade. It is proprietary though, so you need a specific model of RAM.

    The 512 MB upgrade is named CF-BAV0512U (Kingston KTP-BAV4/512), and the 1 GB is CF-BAV1024U (Kingston KTP-BAV4/1G). You should be able to find these online many places. The 512 MB upgrade is about $35 if you look around, I recommend Ark Devices. The 1 GB part was like $175 and seems rarer, so I didn’t bother.

    Comment by Nate Lawson — April 18, 2008 @ 8:48 am

  3. Thank you, Nate!

    Comment by arnon chait — April 22, 2008 @ 10:27 am

  4. FYI – trying to squeeze out some performance on my venerable Y4 and found a 1GB RAM upgrade for $70 from Memory-Up.com. Pleasantly surprised since as you noted – finding a reasonable price is tough for proprietary chips.

    Great writeup on disassembly for the hard drive upgrade – I have been playing with dual booting Windows 7 and Ubuntu – so I might have to take the plunge…

    Comment by Pete — February 7, 2009 @ 4:40 pm

  5. What’s a good temperature range for the CPU ?

    Comment by Mark — July 6, 2009 @ 9:15 pm

    • Depends. I’ve had a Y7 and Y4. The Y7 has a fan and vents, the Y4 only has conductive cooling through a heat pipe. (No fans at all! I like it more than the Y7). In Hawaii in the summer, I had the Y4 get up to 80C and it’s still running several years later. However, I don’t recommend that. I put an ice pack under it to help.

      Comment by Nate Lawson — July 14, 2009 @ 9:44 am

  6. Do you know a good place to buy the AC adaptor and battery for my Y4 ?

    Comment by AD — July 17, 2009 @ 2:26 am

    • The battery part number for the Y4 is CF-VZSU41. It is 7.4V, 7.65 Ah capacity. The same physical form factor is used for the Y2 and Y3 (but not the Y5 or later), so they probably should work as well. No guarantees though. The Y2 battery is the same voltage, but has a lower capacity (CF-VZSU27, 7 Ah).

      You can use almost any AC adapter. I’ve reused one from a Thinkpad before. It has to be 16V and at least 2.5A output (higher is ok for the latter number). The connector is positive (+) tip. I’m currently using a thin Japanese model (CF-AA1625A).

      Comment by Nate Lawson — July 18, 2009 @ 11:18 am

  7. Have you tried running Windows 7 on your Y4 ?

    Comment by AD — August 23, 2009 @ 4:29 am

  8. Thanks for a very informative site! I have a Y5 and want to upgrade to a larger hard drive, but until I saw your post I wasn’t sure this was OK. Fortunately it looks like it’s much easier to swap in a Y5. I’m looking at a 320Gb WD HDD now, very similar to the 250Gb you installed; the reviews I’ve seen agree with what you’ve posted—a good drive but you see a fair # of failures too. I’ve read elsewhere that there are sometimes issues with bigger HDDs e.g. you can’t put more than around 130(?)Gb on because the BIOS/XP can’t recognize past a certain size limit and you get failure messages etc., which partitioning may or may not fix— can you tell me if the Y4/Y5 is OK in this regard? Thanks for any advice you might have!

    Comment by Harry — September 24, 2009 @ 8:22 am

    • BIOS problems with >120GB is a thing of the far past. Neither the Y4 or Y5 would have this problem. As for failures, it’s very clustered on which batch of drives you get. See the Google paper on hard drive failures for some good statistics.

      Comment by Nate Lawson — September 25, 2009 @ 12:49 pm

  9. Can anyone supply me with the CF-Y4 Recovery CD (XP-Prof.). I lost it and need to reisntall my system.

    Comment by Stephan Franz — November 13, 2009 @ 10:35 am

  10. I’m looking for a working display and inverter…for the CF-Y2, that is.

    Comment by Mike Mongo — December 1, 2009 @ 8:09 pm

  11. I have just installed windows 7 on my Y4, but i cant find a sound driver. Can anyone help me with this problem?

    Comment by Heigo Varik — April 21, 2010 @ 6:07 am

    • I don’t know about Windows 7. The chipset is listed as “Sigmatel C-Major Audio” and the driver is STAC97.sys. Here’s what Google says.

      Comment by Nate Lawson — April 25, 2010 @ 10:47 am

  12. I am still looking for the display and inverter. Patience is a virtue.

    Comment by Mike Mongo — April 21, 2010 @ 9:40 am

    • Hi, I have got a working inverter for the CF-Y4 for sale.

      Comment by Stephan — October 9, 2010 @ 4:58 am

  13. Can anyone recommend a source for a new screen for a y4 – LTD141ENAP – yallstore and all its subsidiaries etc. have such amazingly bad reviews, I wont buy from them – Thoughts w/out going to Japan – am in Boston.

    Comment by Tom — April 21, 2010 @ 12:26 pm

  14. Bought the battery off ebay for $20 odd. Works perfectly like new.

    Comment by AD — October 19, 2010 @ 8:21 am

  15. Can any one tell me how to get my function keys to work on a CF-Y4? do i need the drivers for that if so where can i find it?

    Comment by nuwan — November 16, 2010 @ 2:34 pm

    • You probably need a replacement keyboard. Try plugging in a USB keyboard and see if the function keys work.

      Comment by Mike Mongo — November 16, 2010 @ 2:44 pm

    • I think he means the special “Fn” modified keys for display brightness, sound, etc. You need the “Hotkey Driver for Panasonic PC”. Mine is version

      Comment by Nate Lawson — November 16, 2010 @ 4:23 pm

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