System board also know as motherboard
A system board also known as motherboard or mainboard is the main circtuit board in any laptop. Unlike desktop PC system boards, laptop system boards come in thousands of different shapes and sizes. Laptop motherboards are model-specific. In other words, you cannot remove motherboard from a Toshiba laptop and stick it into a Dell laptop. All parts inside a laptop are connected to the system board, either directly via a connector mounted on the system board or through a cable.
In a typical laptop the following ports and components are permanently attached to the system board and cannot be easily removed and replaced without soldering:
1. Hard drive (HDD) connector.
2. CD/DVD drive connector.
3. Memory (RAM) slots.
4. Battery connector.
5. Keyboard connector.
6. Audio (headphone and microphone) jacks.
7. Volume control wheel.
8. USB ports.
9. Eithernet (RJ45 aka network) port.
10. IEEE 1394 (Fire Wire) ports.
11. Video chip and some other components and ports.
System board, processor (CPU) and LCD screen are the most expensive parts in any laptop. In some cases, when one of these three parts fails, it’s cheaper to buy a brand new laptop than replace the failed part. But each case is different so do your research.
The system board is mounted inside the laptop base assembly. In order to remove or replace the motherboard, you’ll have to disassemble the whole laptop.
SYSTEM BOARD FAILURE SYMPTOMS.
When a system board fails, you may experience the following most common problems with your laptop. 1. The laptop is completely dead. There are no LED light activity when you press on the power button or plug in a known good AC power adapter. 2. The laptop starts but the video output on the LCD screen or external monitor is garbled. Most likely this is related to the VGA chip failure. 3. The laptop turns on without video on the screen and the power LED starts flashing. 4. The laptop works fine with AC power adapter but will not charge a known good battery. If that’s the case, most likely there is something wrong with the battery charging circuit or DC power jack.
Need spare parts for your laptop?
If you are looking for spare parts for your laptop you can find brand new and used parts here. Just search by the part name and laptop model.
February 20th, 2010 at 9:52 pm
David Gohr,
Maybe you have a blown power fuse. Usually you can find a fuse somewhere close to the power jack. Test it with a multimeter and if the fuse is open, replace it with a new one.
February 20th, 2010 at 9:42 pm
leong,
Did you test memory modules?
In order to turn on a notebook, you need three main components: motherboard, CPU and memory.
CPU doesn’t fail very often and you’ve replaced the motherboard. It’s likely that one of the memory modules is bad.
February 16th, 2010 at 3:04 pm
Hi! Leong here, my aspire one when switch on when black. only the power light is on. When to acer service centre, say need to replace the whole motherboard. did not make the changes. Need your input what the real problem here.
tks
February 13th, 2010 at 5:31 pm
I have a Compaq Presario F750us. About a year ago a child of mine got ice cream on the power button. It worked fine for the most part after I cleaned it up with a dry rag but the issue now is that the computer will not turn on. I went to a tech who told me that I more than likely blew the power chip that sits under the power button that you press. HP says that I am crazy and it has to be the motherboard. What I want to know is this, can it simply be that the power chip went out and needs to be replaced if that is the case how can I find the part number when the sticker came off with the ice cream? Also the ribbon that leads from the power chip under the keyboard is crimped pretty bad so I think that I would have to replace that too but I still can not find a site to tell me what the part numbers are for this situation. REMEMBER the computer worked perfectly until I shut it off to take it home and when I tried to reboot it it would not turn on. The motherboard has been checked so I know that it is fine is there a way that you can help me find the parts that I need to fix the laptop.
February 12th, 2010 at 9:24 pm
I have a Compaq Presario C504us that stopped working. It will not start with the power cord and the battery does not charge. I purchased a replacement power cord and still will not charge the battery or start the machine. I purchase a new battery and machine worked fine until the battery lost its charge. I checked for voltage after the jack inside the laptop and voltage is fine so it is not the jack. Is there a fuse or something on the motherboard that can be replaced. I am proficient with soldering.
February 10th, 2010 at 10:52 pm
Will,
Maybe one of the memory modules went bad?
If you have two modules installed, you can remove them one by one. Test the laptop with each module separately. It will start fine when the bad module is removed (if it’s faulty of course).
January 29th, 2010 at 9:28 pm
I have a Dell Inspiron 1720 and today it suddenly went dead. Its not the battery nor the adapter. (I have 2 same laptops and interchanged them and it worked in the other computer.) The Power LED comes on and it doesnt flash – stays solid. The hard disk LED flashes for 2 seconds and disappears and i dont hear/see the fan working either. I tried to Fn+Power combo, the middle top 3 locked LED lights come on but again only for 2 seconds. I could be wrong but it seems when the computer tries to load to dvd player then it just dies. Any idea? Thanks.
January 19th, 2010 at 11:17 pm
Jrh,
No, you cannot.
No, you cannot.
January 19th, 2010 at 11:17 pm
jimmyduh,
I’m not familiar with this laptop but most likely it has two memory modules installed. It’s possible that one of the modules went bad and because of that the laptop will not start. I think your problem is not related to the virus infection, it’s just a coincidence.
Try removing memory modules one by one. Test the laptop with only one module installed. Try different slots.
If the laptop worked fine with a 40 watt adapter before the failure occurred, I don’t think it’s related to the problem.
January 19th, 2010 at 7:31 am
mr repairman,
I have an Arima M630-UC Laptop which a friend of mine bought somewhere in china for a very cheap price. The problem started when he download some virus and the laptop just went dead. At first when he gave me i was able to boot it using SLAX but now it wont even boot. LED light is on, the battery is out using AC adapter. I thought it was the CMOS battery (as some of my frind told me) dissamble it and change i with a new one, but still no luck. When I push the button the LED light is on and sound as if it want to boot but it is not. Oh by the way, I check the website it the laptop used a 60 watt AC adapter but i just bought a 40 watt adapter could this be the reason or the motherboard?
sorry for my bad english. I really need help mr repairman
January 19th, 2010 at 2:14 am
i just want to ask u
can i replace a RAM came from a laptop tp PC ??
and also a wireless Lan ??
January 5th, 2010 at 7:40 am
Hi there, it was the CPU after all. Working like a charm now
January 5th, 2010 at 5:50 am
Hi there,
I have an Acer Travelmate 5730 series laptop. Laptop will not POST unless I remove the CMOS battery and replace it. When I do this and plug in the AC adapter the the laptop powers up by itself.
When I remove the CPU from the socket and connect the laptop it will power up for a couple of seconds (power light/charge light + the fanc spins).
I removed and replaced RAM, HD, DVD-ROM, etc and it makes no difference. Only thing I haven’t been able to rest is the CPU. Does this sound like a CPU related fault?
Regards
TheBoyBest
December 29th, 2009 at 9:37 am
jazzmine,
Sounds like you have a problem with the power jack – socket where you plug the adapter. Most likely in your laptop the power jack (DC jack) is soldered to the motherboard. The laptop charges intermittently because the power jack is not making good contact with the motherboard.
The power jack has to be resoldered (or replaced if it’s broken). Here’s what I’m talking about: http://www.laptoprepair101.com/laptop/2007/12/06/dc-power-jack-repair-guide/
December 29th, 2009 at 1:52 am
hi i have a acer aspire 5000 laptop and i cant get it to charge uselly i can get it to take a charge by unpluging the cord and repluging it back in i keep doing it until it starts charging i do not wiggle the cord around like some people do but thats starting not to work the cord does work cause i tested it on my moms laptop and it charges her fine i was on my laptop earlier the battery was fully charged but then it was about to shut down cause the battery got low there is a little juice in the laptop to turn it on for like 5 mintues but im wondring is it somthing wrong with the dc-jack the needle on the inside of the computer looks fine its not bent and i know its not the motherboard cause the computer comes on with no problem is there another reason why a laptop wont charge?
December 27th, 2009 at 11:54 pm
Freddie Ruiz,
First of all, test the power supply. It’s possible the AC adapter is dead. You can test the adapter with a multimeter. Can you read any voltage coming from the AC adapter?
Also, you can try the old trick. Sometimes it helps. Unplug the power adapter, remove the battery. Press on the power button for a few seconds. Now plug the AC adapter and try to turn it on.
December 27th, 2009 at 1:16 pm
Hi repair man my dad’s laptop its a Acer Aspire 5315 and he was just using it one night turned it off and the next day the laptop was dead. It wont turn on any light or led and wont start any internal stuff like the fan. I started thinking that maybe it could be a BIOS problem but my dad didnt make any upgrade. Right now im out options could you give a any ideas.
P.D. I did the fn+ESC+power button but no luck
December 19th, 2009 at 4:07 am
hello
I have a laptop Toshiba satellite brand,it was working before in a good way , one day i turned it on, but nothing on the screen, i feel there is no boot, only power led is on, but no activity for the laptop.
is there any keys for reset the bios or something can help me?
Thanks for your help.
Regards.
December 18th, 2009 at 4:27 am
Hello,
I’ve got a Packard Bell laptop EASYNOTE MX52-B-018 which doesn’t turn on, when i press the power button it lights up for a second and turns off again. I removed the cpu (Athlon X2 TK-55) pressed the power button and the laptop turned on but with no video.
Is it possible the cpu has gone bad?
Thanks
November 26th, 2009 at 1:57 pm
greg,
This sounds like a problem with the inverter board or backlight lamp. Most likely the inverter failure.
But I don’t understand what’s going on with video on the external monitor. Can you get video on the external monitor at all? Will it stay there?