A bad connection between DC-IN power jack on the system board and the system board is a very common problem with Toshiba Satellite M35X and Toshiba Satellite A70/A75 notebooks. If your laptop is out of warranty, then you can fix the problem by resoldering DC-IN jack on the system board. If it’s still under warranty, it would be fixed at no charge to you.
Problem symptoms:
- Laptop randomly shuts down without any warning.
- Power LED and battery charge LED start flickering when you wiggle the power cord or the AC adapter tip on the back or your laptop.
- The battery will not get charged.
- When you plug AC adapter, the laptop appears to be dead and there is no LED activity at all (DC-IN jack on the system board is broken).
To fix the problem, you have to take your laptop apart, remove the system board to resoleder or replace the DC-IN jack. Toshiba Satellite M35X and Toshiba Satellite A70/A75 disassembly guides will help you to remove the system board. Take a closer look at the power jack on the system board with a magnifying glass. In most cases you get the power problem because of a bad connection between the DC jack and the system board, you’ll see a crack between the DC jack connector and the system board.
Here is an example of Toshiba Satellite M35X power jack. The crack occurs between the DC jack pin and the system board.
In some cases the connection is good, but the DC jack is bad itself. You can find a new DC jack for Toshiba Satellite M35X and Toshiba Satellite A70/A75 laptops here. Search for DC jack M35X or DC jack A75.
How to resolder laptop power jack yourself.
UPDATE:
Sometimes, after you replace the jack, you can see that the system board doesn’t get power at all. The battery will not charge and the power LED will not light when you plug in the AC adapter. So, here’s a possible explanation.
When a connection between the positive pin and the motherboard breaks (cracks), the power jack gets loose. You can feel it when you plug in the adapter plug. A loose power jack can damage the trace inside the hole in the system board. Take a look at the picture.
As you see, the positive pin goes through the hole in the system board and you solder it on the top side. Right? What if the trace between the top side and the bottom side is broken somewhere inside the hole? I’ve seen it before a few times. In this case everything looks nice and clean on the top side. When you plug in the AC adapter, you get normal voltage readings between “+” and “-“ pins on the top side, but the power DOESN’T go to the motherboard at all, because there is no connection between the top and bottom sides. Test with a multimeter if there is a connection between the top and the bottom.
If the trace inside the hole is broken you still can fix it. You can run a wire to connect the top and the bottom sides. Be careful not to short something on the board.
Update:
Here’s another solution to fix the power jack problem, it shows how to relocate the power jack outside the laptop base. Check it out here: Toshiba Satellite A75 failed power jack workaround.
When you repair a loose power jack, it’s a good idea to check the jack on both sides of the motherboard. When you remove the top cover from a Toshiba Satellite A70/A75 laptop you can see only points where the jack is soldered to the motherboard as it shown on the second picture in this post, but you cannot see the jack itself as it shown on the first picture.
Removing the motherboard from Satellite A70/A75 laptop is a good idea because the jack itself might has a broken “+” pin, as it shown on the picture below. If the “+” broke off the base, you’ll have to replace the jack.
UPDATE:
Today I received another well written and well documented guide about fixing Toshiba Satellite M35X power connector issue. This guide was submitted by Stephen Macuch. Thank you Stephen for great pictures and detailed instructions.
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February 21st, 2007 at 12:13 pm
I bought a toshiba A70. when my system boots up, it on AC mode, right after the boot up it goes into battery mode. Any ideas
February 19th, 2007 at 8:46 pm
cj2600,
Thank you for your input. The probelm is not the power jack. I have not try to disamble a laptop again since I did it a few times. I got it works by pressing the monitor port down (with something in between the port and the uper casing to keep it down that way). This is just a temporary fix. Sometimes, I experience freezing or unexpected shutdown.
I’m not the original owner of this one so I do’nt think Toshiba is going to give any extended warranty.
February 19th, 2007 at 8:07 pm
Gary,
If you purchased your laptop in the United Sates, this could be your alternative. Read here.
February 19th, 2007 at 7:58 pm
Hey Mark,
Thank you very much for the information.
I mean it’s strange that the motherboard was designed this way. I’m not an engineer but I would avoid any possibility of a spark inside the positive hole.
February 18th, 2007 at 9:54 am
cj2600,
Nothing strange about it , just cross cut any laptop motherboard and you will see layers of ground inside ..
The fix is- first clean the short circut by make hole a littele biger and bend up top trace with botom trace a way from the inside hole … always masure with multimeter to make sure short gone after pull smalll insulation jacket on positive pin of DC Jack and do soldering on top and botom . This should do it ! I did it and now Toshiba Satellite M35x-S149 works again !!!
February 18th, 2007 at 9:49 am
Tom,
When you bend the power plug with a little force, you actually flexing the motherboard. Maybe this problem has nothing to do with the power jack? Maybe there is a loose connection somewhere on the motherboard and when you flex the board it works for a while? You can try this. Remove the top cover and see if you can boot the laptop after you apply some pressure on the motherboard, try different areas. Be careful, do not short something.
I’ve seen a few laptops with a problem like yours. The laptop will not boot when it’s assembled together, but you can start the laptop temporarily when you remove the top cover and push on the motherboard (usually in the area of CPU) just a little bit. You’ll have to replace the motherboard in this case.
February 18th, 2007 at 9:39 am
Mark,
Thank you for the information:
It’s rally strange, and doesn’t make a lot of sense. I’ll take a look inside the positive hole as soon as I can get this motherboard. Weird.
February 14th, 2007 at 2:50 pm
Unfortunately, I found this site too late. My laptop had all the symtoms that you mention. I was downloading overnight when my computer completely fried. Motherboard, hard drive, etc. The plug burned off from the wire. Lucky there wasn’t a fire. Any alternatives for those of us who lost everything before finding the fix?
February 14th, 2007 at 5:44 am
Awesome fix, thanks!
February 13th, 2007 at 7:28 pm
Hi all,
It’s my first post here.
I agree with Mark on #325. I had a M35X with all the lights on, the fan starts for few seconds and nothing else. I have resoldered the power jack, but it didn’t help. If I bend the power plug with a little force either up or down while pressing the power button, the laptop is able to boot. So my guess is that the traces from the inside layers might loose contact or something like that. I wonder if anybody can locate those inside traces that might contact to the + or the – of the power source.
Thank you