Dell studio 1558 CMOS battery connection on motherboard damaged

[raghava216]

My Dell studio 1558 did not boot up last night. So, I opened it up, took out the RAMs, cleaned and replaced them. Then, I felt that the CMOS battery might have gone bad. So, I attempted to take out the CMOS battery from its slot. But, unfortunately the case which is soldered to the motherboard came out at one end. The positive terminal of the battery is connected to two places through PCB tracks, 1 to a via and the other to one end of a resistor. These 2 tracks cut open when I tried to eject the battery. I wanted to connect a wire between the points after scratching out the PCB track. Unfortunately, while scratching the track, the track came out along with the conductor near the via. The other connection of battery positive to resistor is also difficult to solder with wire.
Is there any way to fix this? Is there any other known point where I can wire the positive terminal from CMOS battery?
My laptop is running but displays a message that CMOS checksum is bad, every time I boot. Of course, the time & date are lost after every reboot.
Is it safe to work with my laptop in this condition?
Kindly suggest solution.

[Uranium-235]

Re: Dell studio 1558 CMOS battery connection on motherboard damaged

I've had this happen before, I just unsoldered the whole battery holder, took one out of another motherboard and soldered it back in. Damagjng traces just makes things more difficult. Can you upload a picture of the area (bottom of pcb)

[Uranium-235]

Re: Dell studio 1558 CMOS battery connection on motherboard damaged

Oh wait this is a laptop. In thay case give us a picture of the damaged area. Not sure id this is a smd cmos battery holder or not

[gabik111]

Re: Dell studio 1558 CMOS battery connection on motherboard damaged

Get the schematic diagram and look where the CMOS battery is connected then find better points on the motherboard to solder wires.

[raghava216]

Re: Dell studio 1558 CMOS battery connection on motherboard damaged

Sorry for the delay in my reply. Here's a picture of the damaged area before and after my misadventure. Tracks going near D25 and R597 from the battery positive terminal to be zoomed. Please do suggest a solution. Thanks.

[jpyerry]

Re: Dell studio 1558 CMOS battery connection on motherboard damaged

I had the exact same thing happen to me (on the exact model laptop you have), I went to replace the battery and the holder broke off the board taking the trace with it.

You could probably bodge a small wire in if you wanted to do so.

Here is what I did to repair my board:

I desoldered the existing SMD battery holder.
I bought a new SMD CR2032 battery holder.
I sourced some high purity, very thin copper foil.
I cut out a new trace with an Exacto knife and a straight edge in roughly the same shape as the original trace.
I carefully scraped a small section of the solder mask covering part of the un-torn off section of the trace to expose the underlying copper and added a small amount of solder to the exposed area.
I then glued (using epoxy) the replacement trace into place making sure that the new trace overlapped the soldered section of the old trace.
I then melted the solder so that the two trace were joined electrically.
I painted over the copper foil (except the land for the new battery holder) with new solder mask.
I allowed the new solder mask to cure (sunlight helped the process).
I glued (using epoxy) the new battery holder in place to the board to lend some additional mechanical stability to the board.
I finally soldered the contacts for the battery holder to the board.
I popped a new CR2032 battery in.

The board fired up and has worked just fine ever since.

It was a colossal pain in the behind to do, what I did was probably overkill, but it worked well and I learned a little about repairing circuit traces.

Good luck in whatever you wind up trying.

I wish I had pictures, I ended up giving that particular laptop away about two years ago.

This is why I really hate reworking surface mount technology and it is illustrative of their inherent weaknesses.

All the best,
jpyerry