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.
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May 18th, 2010 at 8:05 am
Hello, I have Lenovo 3000 N200 Laptop. My laptop is not working at all, it wont power on or shows any lights…. it is totaly dead. Please help me. Thanks in Advance.
May 18th, 2010 at 5:01 am
I have an HP Pavilion dv6500 laptop, it does work with charged battery but not without battery and with charger on. I tested with a good charger and it still doesn’t receive power.
Could it be the power connector board (DC input jack and circuitry that transfers the power to the motherboard) or the motherboard itself? If something is burned in the motherboard, is there a chance to repair it?
May 16th, 2010 at 9:55 am
carmine,
First of all, test the AC adapter. It’s possible the laptop will not turn on because the AC adapter is dead and the battery has no charge.
If the problem is still there even with a new AC adapter, probably it’s bad motherboard.
May 11th, 2010 at 3:48 pm
compaq presario v2000 it wont turn on nothing not a sound please someone help. no lights nothing how can i find out whats wrong
May 7th, 2010 at 6:02 am
Hi i have Hp Compac 6735s. Dead. Stripped it to your site. Pc shops says motherboard but i see nothing. Fuse? Does not switch on even with all the power and reset stories. If battery is charged i get 7 led signals when trying to switch on and power led blink and go of again. that is it. What do you think.
May 1st, 2010 at 12:08 pm
emy,
Could be memory failure.
1. If you have two memory modules installed, try removing them one by one and test the laptop with each memory module individually. It’s very unlikely that both memory modules failed at the same time. When the bad module is removed, the laptop should start properly.
2. If reseating/removing/replacing memory modules doesn’t help, most likely this is the motherboard failure. You’ll have to replace the motherboard.
May 1st, 2010 at 11:56 am
i have hp pavillion dv6000.The problem is its just black screen and 3 short beeps.Can you help me to fix it?.thanks!
April 23rd, 2010 at 12:49 pm
storm57,
It’s hard to tell without testing what is causing the problem.
In order to start any laptop with video you need three main components: motherboard (with video card), CPU and memory.
From my experience, CPU failures are not common, so most likely it’s either motherboard or memory failure.
1. Try reconnecting memory modules.
2. Remove memory modules one by one and test the laptop with each memory module individually. One of the modules could be bad.
3. If you still experiencing the same problem even with known good memory, this could be motherboard failure.
By the way, run Memtest86+ (multiple times) and test memory. Maybe one of the modules fails intermittently.
April 23rd, 2010 at 12:29 pm
I have a Presario F700 laptop that has a mind of it’s own. Whenever I hit the power button, the thing turns itself on and off several times before it finally reaches the POST and boots. What are the possibilities for the problem? The battery, and adapter test out fine. And once it boots, it works without any hassles, until I shut down or reboot.
April 18th, 2010 at 5:33 am
Hi,
I can’t find the fuse on my HPDV 9000 do you have any website or manual guide I could use to locate it?
Thanks
April 17th, 2010 at 10:43 pm
Mark,
I don’t think that your problem is related to the fuse.
Usually the fuse is located somewhere close to the DC jack (or DC jack harness). The fuse is soldered to the motherboard. In order to replace the fuse, you’ll have to desolder the failed one and solder a new one. Before replacing the fuse test it with a multimeter.
April 16th, 2010 at 2:11 am
Hi,
I have a HPDV9000.
I just sent it for a complete repair of the graphic chip, I then booted my laptop, everything was fine, image on the screen was normal; 30 minutes after it began to vibrate quite loudely somewhere around the fan or the hardrive ; I just pulled the AC/DC adapter right away and the battery was not plugged in. After that I tried to boot it but no reaction just the blue light where you plug the adapter.
I checked my ac adapter and the DC-IN harness, voltage is fine.
But I can’t locate the fuse on the motherboard, anyone has a pictures or a website that I could use?
How much does a fuse coast and is it easy to replace?
April 7th, 2010 at 4:59 am
Hello, I have an Acer Travelmate 2480 and my computer just won’t turn on. When I push the pwer button, an orange light flickers in the front by the speakers. This happens with and without the power adapter plugged in. Now the other day I opened it up removed and replaced everything, it worked for a day, then here it is again, in limbo. Any suggestions?
April 4th, 2010 at 11:34 am
Sure,
ac adapter works!
I can try to change the fuse?? But i don’t fount PF1 or F1 pin on motherboard pcb! Help me
April 4th, 2010 at 11:15 am
Korben,
Did you test the AC adapter? Maybe the adapter is not working properly when loaded. I would suggest testing the laptop with another known good AC adapter.
If the problem still exist, most likely this is the motherboard failure.
April 4th, 2010 at 11:00 am
Sorry… my pc is hp pavilion dv6693el.
April 4th, 2010 at 10:59 am
Hi,
Help me!
i have same problem…. pc works only with battery but not works with AC adapter,this one don’t charge the battery!
So i found the fuse, but it is ok… the tester sounds when i test it!
March 10th, 2010 at 2:48 pm
i have an acer tm 5520. with pomona motherboard. my battery was broken and laptop cudnt power on. i checked few things, assembled it back, and it was running again ( without battery ) i poured some glue on the power jack to fix it in the casing because it got loose. next morning i tried to fit in battery, but it didnt power on. and when i hooked it with adapter without battery it was dead. no l.e.d no power. its been dead since. i had it checked in the market but they cannot figure out the problem. when i check for ac voltage with a multimetre, it seems to get same volts on the ac jack as from adapter, but when i go further, multimetre detecs low volts.
i have another laptop same model. unlike above, it shows same voltage from adapter to ac jack and to battery terminal.
does anybody have any clue whats wrong with my computer? can u suggest me anything? thanks
March 3rd, 2010 at 10:02 pm
vince,
Here’s service manual for Acer Aspire 4720G, 4720Z, 4720 and 4320 series.
Now you know how to get to the power jack.
Good luck!
March 3rd, 2010 at 2:42 pm
I have a Acer Aspier 4720Z. The problem I have is the compter wil not charge the battery or work when plugged in (if the battery is removed). I think it’s the DC board and input, the ac adapter is ok. I could easy replace the board but I don’t know how to get to it.
February 14th, 2010 at 12:12 pm
Hi
I have an Acer Aspire 6920G which has an unusal fault. It will not power up buy has a faint ticking sound. I stripped the motherboard bare & still the ticking sound persists. I have removed various caps, coils, resistors etc but still cannot work out where the sound is coming from! Is there an easier way to try pinpoint the source of this fault? I have tried listening all over the board by ear but the ticking sound seems to be the same – neither louder or softer. Are there components on a motherboard that would be more prone to tick when they have failed?
There are a few caps that are shorting in circuit. I removed & tested all of these and they are good but there still is a short. Strangely though this short does not affect the power supply to the motherboard ie. by turning power supply off or indicating there is a short (flahing led).
This is actually the 2nd motherboard I have come across with the same fault & still cannot solve this problem.
Any advice will be greatly appreciated!
Thanks in advance..
February 11th, 2010 at 10:52 am
BM,
Is it normal? I believe it has to be on all the time when connected to the wall outlet, isn’t it?
Before replacing the motherboard, I would suggest testing the laptop with another AC adapter. Maybe the adapter is bad.
Did the laptop work on the battery power before?
It’s not likely but possible that you have a damaged DC jack inside the laptop. Maybe it shorts something when the AC adapter is plugged.
You can remove the cover and take a closer look at the jack. Maybe the jack has to be resoldered. Just a guess.
The best way to find a new motherboard is searching on the internet by the part number. Usually in Dell laptops you can find the motherboard number on a sticker glued to the memory slot. There is a long string of number on the sticker separated by dashes and one part of number will look like CN-0MD666. This is the motherboard part number and you can google it or search on eBay. The number could be different for your motherboard.
It’s not necessary to buy a new motherboard directly from Dell but buy it from a reputable seller.
February 11th, 2010 at 6:46 am
Hi! I have a dell inspiron 6400. My laptop doesn’t start. The adaptor light blinks when I connect it to the power supply, but as soon as I plug the jack into the laptop socket, the light on the adaptor goes off. And my laptop doesn’t start. The battery gage shows that it is charged. I have tried removing the battery and running only on AC power, but it shows the same symptons. I have tried removing every component and powering the motherboard directly, but with the same results. I am assuming that the motherboard is faulty; where can I directly purchase a new one; can i purchase a particular model of motherboard directly, or will i have to deal directly with Dell? If a particular component soldered on the motherboard (like power jack) is faulty, is it possible to remove it, purchase a new one and solder it back? Thanks a lot.
February 9th, 2010 at 4:02 pm
lee hennessey,
Sounds like software related problem. Could be corrupted registry.
Can you boot in Safe Mode? Try using Last Known Good Configuration too. You can access both if you press F8 as soon as Dell logo appears on the screen.
If nothing helps, you’ll have to reinstall Windows from scratch.
February 9th, 2010 at 2:02 pm
hi there my laptop is a dell latitude d600 it starts up and gets to windows xp loading bit then goes back to the start does it all the time can you help
January 23rd, 2010 at 7:23 am
My Dell Inspiron 600m will intermittently not power on. Does not seem to matter whether the laptop is running on battery or AC. The LED indicates a charging battery when plugged into the wall. I push the power button, nothing happens. Push it again over and over, eventually it will power on. Runs normal when powered on, and if I do a soft restart, it shuts down and powers up normally. But if I shut down completely, the next time I hit the power button I have to hit it over and over until one time it works.
So, could it be the AC, motherboard, power board, or something else? How do I diagnose the problem?
January 5th, 2010 at 10:28 am
Tenzin,
I think your problem could be related to the memory (RAM) failure.
You have two RAM modules installed, correct? Try removing them one by one. Try starting the laptop with only one RAM module installed.
If it starts fine with one module but not with another, the second one is bad.
January 4th, 2010 at 8:24 pm
I have a acer aspire 5630 for while, but now its not working properly, when I tried to start it, the fan runs only for 5 to 10 seconds and after that there is only power led on but nothing else is going on, i can’t hear hard disk sound etc, any suggestion??? I think its fan problem but am not sure about this, you help will be very appreciated, thanks a lot
November 27th, 2009 at 11:21 pm
Malik TOKA,
Sounds like you have a failed motherboard. Sorry, I cannot help you to fix it. I don’t work on the component level. If the motherboard fails, I replace the whole motherboard.
November 27th, 2009 at 10:22 pm
ladoks,
Processor failures are not common. I’ve replaced hundreds of failed motherboards and only very few failed processors.
If you have to choose between the motherboard and processor, go with the motherboard.