Apple Powerbook 520 & 540 Modifications & Fixes

Updated 5/20/99.

I had two Apple 520c powerbooks. This page details things I did to repair problems I encountered and modifications I tried that worked. Almost none of these repairs are for the faint at heat. I provide this information for you to use at your own risk. I fully believe it to be accurate and true, but I provide no warranty. Your powerbook contains static sensitive circuitry and it is very easy to destroy it without even realizing what you have done. Be sure to work at a static free workstation and keep you and your work grounded at all times.

Add an FPU to your Powerbook 520 or 540

If you have the equipment and skill, you can obtain from Motorola a full blown 68040 CPU and unsolder the surface mount 68LC040 and solder in the full blown version with the FPU. The exact part you need depends on whether you use have a 520 or a 540 CPU daughter board. The 520 daughter board uses a 25 MHz version, the MC68040FE25V or the MC68040FE33V or anything faster. (The 25 and 33 specify the 25 MHz and 33 MHz versions.) If you are modifying a 540 CPU daughter board, you will need something 33 MHz or faster, the MC68040FE33V or the MC68040FE40V. You will also need a small Torx #8 screwdriver to open your powerbook.

  1. Remove the 2 screws that hold in the keyboard on the bottom of the powerbook.
  2. Remove the keyboard (it will still be attached by a ribbon cable - you can disconnect it but it's not required). Be careful with these ribbon cables. They can tear easily!
  3. Remove the 2 screws on the back on the powerbook inside the flip cover. (They are on each side of the serial number plate.)
  4. Now you will be able to take out the plastic strip under the screen.
  5. Remove the 2 screws holding the metal grill in the middle of the powerbook.
  6. Remove the 1 screw at the back of the grill (which you had to remove the plastic strip under the screen to get to).
  7. Take out the grill.
  8. If you have a memory card currently - remove it.
  9. Remove the old processor daughter card.
  10. Carefully unsolder the old 68LC040 from the daughter card. I recommend using the latest in technology. No ordinary soldering irons PLEASE! There are around 180 pins on this surface mount IC. It is imperative that you do NOT damage any of the pads on the circuit board.
  11. Carefully solder in the new surface mount 68040. This is also a very tricky operation. You need the correct tools, and expertise. I've been soldering since I was a teenager, but I don't consider myself good enough to do this step and the last one. I had my friend, and expert solderer Jim Forsyth at the college's Technical Services Shop do the work with me looking over his shoulder.
  12. Reassemble in reverse order.

Fix a Shorted Cell in your PB500 Battery

When your battery won't charge anymore, then it might be a shorted cell, as it was in mine. You can replace all the cells as well. I have done two at this time.  This is actually a much better solution than just fixing the shorted cell, but it will cost you about $50.  If you are interested in this, see the next section.  The first step in fixing your battery is to open it up. Do this at an anti-static workstation.

  1. Remove the darker gray end cover from the battery pack. You can twist it off with your hand. It takes a little force, but it comes off.  Remove the slide on safety cover for the battery connections from the other side.
  2. Using a knife, cut the rectangular plastic panel on the flat side of the battery (the side of the battery that faces the back of the powerbook when installed in the powerbook). You will now see the on board processor and battery charging circuitry on a little circuit board that fits in this rectangular space. Note that you can tell which side of the plastic cover overlaps the other now.
  3. Using the knife again on the side of the battery that the end cap was on you can cut between the two plastic halves of the case. You can do the same on the side of the battery that is rounded and is closest to you when mounted in the powerbook. It is a little scary, but you can pry the two halves apart. I let it hinge on the part with the electrical connections.  Here are some photos of the insides of the battery packs.  First one.  Second one.  Third one.  Forth one.
  4. Cut the electrical connections to the three places on the cells in a way so that you can solder them back together again later. Use a voltmeter to locate any shorted cells.
  5. Charge a large capacitor (I used 3500 uF at 75 volts). Discharge it through the shorted cell/cells you found, with the positive end of the capacitor going to the positive side of the battery. It will burn off any dendrites that have formed to short your cell.
  6. Solder the cells back in and re-assemble the battery pack.
  7. Re-insert the battery. Use the Intelligent Battery Reconditioning software from Apple or from Lind Electronics to reload the EEPROM on the battery board. Then let it charge. Don't be discouraged if the software claims that something is wrong and you need to send your battery back to Apple. Mine said that, but my battery works just fine. Let it charge.

Replace the Cells in your Intelligent Battery

This is a better procedure than fixing the shorted cells in your powerbook, but costs about $50 for the cells, assuming you buy them from Digikey.  Digikey stocks the Panasonic cells with tabs.  The cells you will need are Panasonic HHR-210A, or you can use Sanyo HR-A cells.  Be sure and get cells with solder tabs.  (If you can't find ones with solder tabs, I found a place in California that would weld them on for $0.50 each plus postage.  The company name is TNR, and their address is:  1779 Main, Suite A, Irvine, CA 92614.  I believe their phone number is (800)490-8418.)  I've had better luck with the Sanyo's, probably because the ones I got were from newer stock.  The rough procedure is outlined below:
 

  1. Remove the darker gray end cover from the battery pack. You can twist it off with your hand. It takes a little force, but it comes off.  Remove the slide on safety cover for the battery connections from the other side.
  2. Do everything that follows in a static free environment.
  3. Using a knife, cut the rectangular plastic panel on the flat side of the battery (the side of the battery that faces the back of the powerbook when installed in the powerbook). You will now see the on board processor and battery charging circuitry on a little circuit board that fits in this rectangular space. Note that you can tell which side of the plastic cover overlaps the other now.


    Using the knife again on the side of the battery that the end cap was on you can cut between the two plastic halves of the case. You can do the same on the side of the battery that is rounded and is closest to you when mounted in the powerbook. It is a little scary, but you can pry the two halves apart. I let it hinge on the part with the electrical connections.  Here are some photos of the insides of the battery packs.  First one.  Second one.  Third one.  Forth one.

  4. Remove the old cells, being careful to note the polarity, and connections  Replace the old cells with new ones.  Be sure to replace the temperature sensors and thermal fuse.  (I think that is what they are, anyway.)  Also, be sure to make all solder connections as small as possible, because it turns out to be a bit tricky to get all the cells to fit back inside the case.  Be sure that there is no possibility of shorting cells out.  (Remove excess parts of the tabs.)
  5. Re-assemble the battery pack.  The end caps hold everything together.
  6. Use the software available from Lind Electronics (BU500 Deluxe 2.01 available below) to set the battery to the original settings.  You can also pick whether to set them to Panasonic or Sanyo settings.  Don't be too alarmed if there are some errors that can't be fixed.  I've had this problem on three of three batteries I've tried, but only one of them didn't work.

    Lind Battery Utilities 500

    For use with PowerBook 500 series that have not been upgraded to Power PC.

    Download it!

    Installation Instructions
    1.  Insert the floppy disk into the PowerBook 500 series floppy drive.
    2.  Drag the file named "BU 500 Deluxe" onto your hard drive.
    3.  Drag the file named "Battery Capacity CS" into the Control Strip Modules folder located in your System Folder.
    4.  Restart your Macintosh.

    Note:  (The files found in the "Assorted Control Strip Modules" folder are shareware programs and are not a required part of the BU 500 program.  They are installed by being dragged into the Control Strip Modules folder located in your System Folder.)

    Starting the Software
    1.  Double click on the file named "BU 500 Deluxe".
    2.  Operating instructions are found by clicking on the desired Topic in the left hand window.
    3.  The right hand Discussion Window then displays the desired information.
     

  7. Charge the battery.  Note how it charges up.  If it isn't taking a full charge, at first, don't be discouraged.  The data sheet for the NiMH cells says that batteries that have been stored for a while won't charge fully for a few cycles.  The symptoms of this problem is that the battery will charge at a normal rate for a while, and then when it still is not fully charged (several segments aren't darkened on the indicator) it will all of a sudden claim to be fully charged.  On the discharge, the opposite happens.  It looks like you have plenty of time left, and then all of a sudden you are empty!  I had this problem with the Panasonic cells I got.  (I didn't get them from Digikey.)  In fact, with the Panasonic cells I tried, the original capacity was only about 20%.  After about five cycles, the capacity is about 80%, and I expect it to continue to increase to 100%.  Let me know how it works for you.  I'm looking for more hints to put on this page, especially on this topic, because I think the batteries are the only big thing keeping me from using my trusty 520c for many years to come.

Did your Port Cover Come Off?

Well I've got two Powerbook 520 notebooks, and both of mine came off. The one at home we leave connected to the printer and the telephone all the time. My wife said she preferred having it off because it wasn't flopping in the way all the time. The one I carry around the office I decided to fix though. Here is what I did.

  1. I found two small screws, a little smaller than 1/16" in diameter and about 1/4" long.
  2. I drilled a hole in each of the corners of the port cover so that when I screwed the screws in I had a replacement for the plastic bump that held the cover in place originally.
  3. I could then put the cover on and screw the screws in so it won't come off again (so easily anyway).
  4. Here is a photo.

My Powerbook Won't Turn On!

I had this happen when my powerbook was quite new. I almost sent it back to Apple, but then I discovered if I left it charging overnight, it would come on again. Try this trick before panicking!  I've also noticed that the power connectors on these powerbooks can be rather flaky.  I'd be sure that it is fully plugged in as well.

Links to Other Powerbook 500 Series Pages


If you have specific questions about these fixes or modifications feel free to send me an email.  My address is my first name "dot" my last name  "at sign" wallawalla "dot" edu.  I plan on putting some photos that will make the descriptions more understandable in this document as soon as I get the digital camera I ordered.