HomeLet’s say your laptop does not start at all. You plug in the power adapter and press on the power button, but the laptop will not react. It’s dead and the power or battery charge LED will not light up.
What could be wrong? Is it bad power jack or the motherboard is dead?
By the way, the power jack aka DC-IN jack is the power socket on the side or back of your laptop where you plug the AC/DC power adapter.
I’ll explain how to perform basic troubleshooting and find out what is wrong. This is only for experienced people, who know how to disassemble laptops.
First of all, test the AC/DC power adapter with a multimeter. It’s very likely that there is noting wrong with the laptop and your problem is related to the power adapter.
If the adapter tests fine and output correct voltage, disassemble the laptop and remove the top cover.
As you see on the first picture, in my laptop the power adapter plugs into the DC-IN power jack which is connected to the motherboard via a harness.
In some models the DC-IN power jack is soldered directly to the motherboard.
Plug in the power adapter and measure voltage at the point where the DC-IN jack or DC harness (like in my case) connected to the motherboard.
If you are reading the same voltage as on the AC adapter, it means the power jack or harness works properly and the problem is related to the motherboard.
If there is no voltage, most likely there is a problem with the jack or hardness and it has to be replaced.
By the way, in some case the problem could be related to the fuse which is usually located somewhere very close to the power jack/harness connector. You can test the fuse with a multimeter.
If the fuse is bad, the motherboard will appear to be dead even if there is nothing wrong with the power jack and AC/DC adapter. If that’s the case, replacing the bad fuse should fix the problem.
March 10th, 2012 at 7:07 am
compaq cq50, I installed a new dc jack harness, works great now , charges battery….everything reassembled perfect..this morning around 3am worked great, went to bed and woke up. Went to turn on and it requested startup repair, started it , it shut down and now won’t turn on , no response and NO led on dc jack…ANY Options, even tried the hp/compaq hard reset….no avail on that either….HELp , I am a techy guy but am currently stumped..not even sure as to why it wanted a startup repair
March 9th, 2012 at 4:28 pm
hey i have a gateway laptop and my problem is that it wont stay on, it turns on for like a minute then it turns off and on by itself. i want to do a restore on it but i cant access it from my other working laptop. What should i do?
March 9th, 2012 at 11:33 am
@ Steve,
First of all I would check the AC adapter.
Do not trust the universal adapter.
Also it’s possible your original HP adapter not working properly under load. I’ve seen it happening before.
I would try to find another adapter for test.
If it’s not the adapter than it must be the motherboard related failure.
March 8th, 2012 at 5:41 am
After hours of google’in I have come across this webpage.
This one is a little complicated, but I will try my best to explain.
I have a HP DV9700 (DV9823em)which has a power problem, it will run fine on battery, but it will not run on DC via adapter.
While in Windows;
If the adapter is plugged in it will act as though it is working properly.
The battery icon will say it is charging when it isn’t, battery level drops.
The auto power option will put it to maximum performance / full brightness.
When the adapter is pulled out it will dim the display and set the auto power options to the battery saver.
If the battery is pulled out when the adapter is in it will instantly turn off, completely dead.
The laptop will only power up when a battery with some charge is being used.
I have tested multiple parts.
It is not the battery, as I have 2… These are being charged using a faulty laptop mobo.
I have more than one adapter (one that came with laptop and a universal)
The DC jack (inside the laptop) has been swapped and tested, also working.
All the parts have been cleaned and I have tried to find any blown/faulty/missing parts on the motherboard to no luck.
I’m taking an assumption that the power is being read going into the laptop but stops/gets drained before it gets anywhere.
Help would be greatly appreciated.
-Steve
March 7th, 2012 at 3:29 pm
@ Patrick,
Have you tried reseating the battery?
March 4th, 2012 at 3:22 am
Hi there, my sister has dropped her acer 5551 and it now does not power up with the battery in. but it powers up using only the AC adapter fine.
is it likely that something inside is damaged or shall we risk buying a new battery first?
thanks
February 27th, 2012 at 2:43 pm
@ SARAH. …. I understand your problem.. please check you need to replace CMOS battery… That problem held because your CMOS battery dead…
February 24th, 2012 at 1:55 pm
@ crackweezy,
I think G50 and CQ50 models are identical. Probably they have different names for different markets.
Here’s the motherboard removal guide:
http://www.insidemylaptop.com/remove-motherboard-from-compaq-presario-cq50-cq60-cq70-laptop/
February 24th, 2012 at 1:51 pm
@ faizan,
This could be memory related failure. Maybe one of the modules is failing of has bad connection with the motherboard.
Try reseating memory modules. Test the laptop with only one (either one) module installed.
February 21st, 2012 at 8:33 am
can G50 motherboard fit into CQ50 laptop case