Thinkpads Forum

Our 310ED (2600-50U) has served well since we got it new in 1996. It was put away for several years, but I started using it about 6 months ago. It was running fine until a few days ago. I turned it on, the hard drive light blinked, the floppy drive started, and the CD drive started. However, the screen stayed blank. Nothing else happened. I tried restarting several times with the same results, then it booted normally once, but never again in another 15 or so tries.

Looking through the forum, next step seems to be to replace the backup battery (part 16 on page 78 of the hardware maintenance manual). As I read the manual, it looks like I must almost completely disassemble the ThinkPad to replace the battery. Is that correct? Can most of the bits be left on the chassis when digging down to the system board? Any lessons learned for this task would be most welcome.
Thanks,
Howard

Having ripped apart my 310ED a number of times in the last year and a half when I was miodding and experimenting with it, It should not be too difficult to get down to the CMOS battery from what I recall. I do not have the hardware manual in front of me but it sounds like you do, which I highly recommend for this project. If my memory is correct, here are the steps I took to get access to the motherboard (on top of which the battery is located):

(1) Unscrew the four small screws holding the two LCD hinge covers down. The screws are located on the backside of the computer and there are two for each hinge cover.

(2) Remove the two LCD hinge covers. These pull right off if you lean the LCD back a give enough room to get them out.

(3) Pick up the keyboard out of its holding tray. Keep in mind the keyboard is connected by cabling and connectors on the front right side so I usually pick up the keyboard from the back and flip it over onto the palmrest.

(4) Optional: Disconnect the three keyboard cables from the connectors. Frankly, I usually leave the keyboard flipped over on the palmrest and work around it when I am in a hurry to get inside the computer but it is likely safer for the keyboard connectors and cables if you disconnect them and then take the keyboard out of the way. Just for ease of work, I would disconnect the keyboard and move it away if it were my first time inside the computer. It should look something like this after the keyboard is off:

http://www.aichi.to/~thinkpad/tp315ed/tp315ed_17.jpg

(5) Unscrew the aluminum thermal plate. Four screws surrounding the processor hold it down and each one is about a 3/4-inch long.

(6) Remove the aluminum thermal plate. It takes a little jiggling and you have to slide and lift the thermal plate out a certain way because of some tabs on the backside of the plate but it should lift right out after the screws are removed. Set the plate aside by laying it on its top so that you do not get dirt or dust on the rubber thermal pad on the underside of the plate that makes contact with (and takes heat away from) the processor. The inside of the computer will look something like this picture of a similar model:

http://www.aichi.to/~thinkpad/tp315ed/tp315ed_10.jpg

(7) Replace battery on motherboard. I believe it is located under a little snap/harness farther back behind the processor. You unsnap the harness, replace the battery and then snap the harness back in place.

(8 ) Reassemble computer in reverse order of above.

Good luck!

Toddyjoe, would that it were so simple as you speculated. Thanks for the encouragement. You are 100% right in saying the steps you describe should get to the backup (CMOS) battery. However it gets only about 10% of the way there. Someone should be shot for burying an item that is designed to need to be replaced. You have to get the system board off the chassis to replace the battery. That means almost totally disassembling the 310ED. I'll commend the hardware maintenance manual, pages 39 through 62, for making the procedure fairly straight forward. Working at a leisurely pace, I took about two hours to get in and back out again. At least by the time IBM designed the 600E, they made the battery accessible.

Things I learned to do differently from the manual were: (1) do not remove the fan, (2) do not remove the battery connector board, just unplug its cable (3) do not unplug the speaker and cover switch cables; the cables are long enough to tilt the system board away from the chassis to get to the battery (and for those really going step-by-step through the manual, do not disassemble the upper base or LCD panel).

Unfortunately, the new battery made no difference. The 310ED still does not begin the boot sequence.

Confession time - I disabled the ThinkPad myself while I was poking around inside. I left the CPU loose in its socket. I was reluctant to push the CPU sideways as firmly as needed to lock it securely. Once I did that, all works properly again. Now I have a new backup battery which should be good for at least 10 more years, and I know more about the insides of a 310ED than I ever expected to.

This was a prelude to hot-rodding the 310ED like toddyjoe did. I bought an AMD K6-2 400 ACK and am tinkering with it. I'll post information and help requests about that in the thread toddyjoe started "4th Update: Running a 310ED at 400 MHz with 128MB RAM" at http://forum.thinkpads.com/viewtopic.ph ... highlight=

Hello!

I too just recently had to replace my CMOS battery. Not having any experience at all taking apart a laptop, it was quite a feat. I did finally manage to find the CMOS and replaced it. My problem is now my 310ED will not turn on, but when I plug the regular battery into the slot the green light comes on, but will not boot when I push the power button. With or without the regular battery, it does not power on. What am I missing? How can I tell if its caput now?

Any help and suggestions are appreciated.

MarshaG.

Marsha,
My first guess is that a connector or something is a bit loose inside after the CMOS battery replacement, like I did with the CPU mentioned a few posts above. I have no idea what exactly would cause the behavior you describe. I suggest digging back into the ThinkPad and checking the connections.

When you press the power button, do any of the indicator lights blink? Any sounds from the floppy or CD drives?

Did you get the manual, available at ftp://ftp.software.ibm.com/pc/pccbbs/mobiles/310hmm.pdf ?
Regards,
Howard

hrmcrm,
Thanks for you reply. Luckily, I have been using the hmm, though I find its not the easiest thing to understand, for me.

This is probably a stupid question - is it possible I could have gotten the battery in backwards.

Absolutely nothing happens when I press the power button. Before I put it back together the last time I know the speakers were plugged in, but I don't recall if there was something in between the two circuit boards I may have missed.

Anyhow, it was working until I tried to fix it LOL

Any other suggestions greatly appreciated.

MarshaG.

I guess it is possible to install the battery backwards. My memory of the battery holder from when I saw it a few months ago is a bit fuzzy. The hmm shows + must be to the front. The sketch in the hmm looks like the holder could fit the battery either way around, although I do not know how much detail they would have tried to show.

Anyone out there know of a loose connection inside a 310ED that could leave it completely unresponsive to the power button?

Hello!

I took the laptop apart one more time and verified the batter was in correctly, that the speakers and fan were connected correctly and the cover switch was also hooked up. I plugged in the AC adapter and got nothing. I put the rechargeable battery in and got a green light until it ran down enough to turn orange, but the power button still did nothing. All I can figure is I must have shorted out the power circuit somehow.

Well,... now what can I do with a broken laptop - anything besides a doorstop??

Thanks everyone for your suggestions.

MarshaG.

Did the battery light go from green to orange while the AC adapter was plugged into the TP and power? If so, I speculate that something is wrong with the connection of the charger board (page 60 of the hmm), or the battery connector board (p. 55). Try checking the continuity of the wires and plug of the battery connector board to be sure one did not break. Also, make sure one of the many pins on the charger board did not get bent out of place. Easy for me to say, rather time consuming for you.
Best of luck,
Howard

Howard,
When I plug the AC adapter in I get nothing - not even a green light. When I put the rechargeable battery in, I get a constant green light that turned to orange after a minute or two, but still nothing powered on by pushing the power button. I did look at the pins on the charger board when I had it apart and they all looked straight and fine to me.


oh well,... at least it wasn't a brand new laptop.

Thanks for all your help.

MarshaG.