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.
Laptop parts | Repair Man | 
December 26, 2008 3:45 pm
299 Responses to “System board also know as motherboard”
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Pages: « 12 … 11 10 9 8 7 6 5 [4] 3 2 1 » Show All
August 1st, 2009 at 2:39 am
Hi,
I have an IBM R51 laptop. The usb ports/ethernet port/ pcm slot do not work due to a spark in the circuit. The CD rom will write CDs only sometimes and now the keyboard has stopped working.
It starts working by itself.
1.) I am thinking about replacing the keyboard so atleast my work can resume.
2.) I want to replace the motherboard but not spend too much many as it is an old laptop. Are there any other motherboards that I can use on the R51?
Thanks in advance,
Varun
July 25th, 2009 at 8:44 pm
Jason,
Sounds more like a problem with the motherboard. From my experience I can tell that CPU failures are very rare. In 5 years I’ve seen only 5 or 6 failed CPUs but hundreds of failed motherboards.
July 23rd, 2009 at 4:20 am
Hi, I have one IBM R51 laptop. One day it was just dead. When I plugged adaptor, only battery light on. Nothing else no sign of life. I striped all the parts, and plugged the power and still nothing comes to live. I test the ram it is good as well. I wonder if the Processor’s problem? but I didn’t hear beep or anything since the laptop has no life though.
Help please
July 16th, 2009 at 10:18 pm
Jane Thomas,
If you get the same gray lighted screen with vertical lines on both internal and external monitors, most likely there is a problem with the video card. In most laptops the video card is integrated into the motherboard and if that’s the case the whole motherboard has to be replaced.
I have no idea why they sold you the battery.
The laptop should run fine even if you have no battery installed. I rally doubt that your video problem is related to the battery.
July 16th, 2009 at 9:55 pm
George,
Search for any stickers on the motherboard. Look in the RAM compartment, under the keyboard, etc…
Google any number you can find. It’s possible one of them is the motherboard number.
July 16th, 2009 at 9:54 pm
Royce420,
Can you enter the BIOS setup menu and check video settings in there. Maybe the internal monitor got disabled somehow? Set BIOS to defaults.
Start your laptop in the dark room. Take a closer look at the LCD when the laptop starts. Can you see the LCD changing color at all? Is it completely dead?
The signal still generated by the video card but it might go through a different channel when you use the VGA output.
Maybe there is a problem with the connector where you plug the video cable?
July 16th, 2009 at 9:55 am
I have a Dell 1330 and I started having a problem with laptop crashing. Suddenly purplish haze tracks would take over the monitor and then it would crash. I used to be able to turn it off and on when this would happen but now the that won’t work. I just get a gray lighted screen with vertical lines. I hooked my laptop to my desktop monitor and had the same problem. I called Dell and they ran some tests via the phone and came to the conclusion that I needed a new motherboard, but they had me buy a battery also. does anyone know why I needed a battery? The rep told me not to connect the old battery once the new motherboard was installed. What does one have to do with the other?
July 13th, 2009 at 12:06 pm
Hi! I have a gateway model M-1624, i need replacer the motheboard, but not find the part. help me please to find!
July 13th, 2009 at 9:07 am
I have an Dell Inspiron 1720 laptop. One day the video just stopped suddenly. I have replaced the lcd and ribbon cable with no improvement. I don’t think it is the inverter because I can not see anything at all, not even the faintest item on the screen. I have the 8600m video card that can be replaced without replacing the system board. The VGA out still works. If the VGA out works, is it running off of some onboard video chip or is it still running through video card? Any help? Thanks.
July 7th, 2009 at 8:04 pm
i have a panasonic laptop that fell out on the table and now I can even turn it on
July 3rd, 2009 at 2:34 am
how can i use my voltimeter to test my motherbord of my laptop to know where the problem is? coz i use it to test power after the power jack on the board and i found that the power connected and it read it 19v although the laptop is dead and when i press the power button Nothing happen so please Help? laptop is Acer
July 1st, 2009 at 3:19 pm
kokting,
Which light is blinging? The power LED or battery charge?
It’s possible that you have a bad AC adapter. You can test the adapter with a voltmeter. Make sure it outputs correct voltage.
June 25th, 2009 at 11:21 pm
hi I’m having problem with my ACER travelmate 290
can’t power up
when I press the power button all the light blink awhile and nothing work (fan, HD, LCD, Wifi, charging LED)
try reseating the RAM/HD/DVD Rom but not works
June 20th, 2009 at 5:42 am
Hi, I have a question about my laptop. Just yesterday, I tried to switch it on. The lights came on but the screen was black (like nothing was loading). I had to manually shut it off. The second time was successful but I had to restart due to an update. The screen froze and I had to manually switch it off.
I already did the whole remove-battery-and-use-only-adapter. It worked on the second time I switched it on.
Today, I switched on my laptop (with battery and adapter) and it worked great. I thought it was just a case of simple overheating. The second time I turned it on, the same prolblem occured. It was only after the third try that the laptop booted up correctly.
Do you think it’s a case of the motherboard?
June 19th, 2009 at 11:59 am
Mark,
Most likely yes. If it would be just a bad keyboard, the laptop would start. I think she damaged the motherboard.
June 18th, 2009 at 1:51 am
Excellent articles.
I have a friends laptop here. Light comes on whern push on button but it doesn’t stay on. There’s no fan, hard drive lights or other activity. She spilled coffee into the keyboard. Is the most likely scenario a fried motherboard?
June 11th, 2009 at 8:26 am
juan,
Sure. Here are instructions for taking apart a Compaq Presariro F730US. Could be very similar to your notebook.
June 11th, 2009 at 6:37 am
i have a compaq presario f750us notebook pc that may have its motherboard fried. it fell of my bed and landed on top of its key board. now it wont turn on but the led charging light turns on so i know it cant be my adapter. so now im trying to take my laptop apart but im stuck on taking the case cover of. do u know of any videos or manuals (other than the company’s manul) that can help me?
June 7th, 2009 at 8:43 am
Ahamed Affan,
The eithernet port is soldered to the motherboard. I guess you can unsolder the busted port and solder a new one, but I don’t know where to buy a new one.
1. You can search for a damaged motherboard on eBay. If you find one, unsolder the eithernet port and solder it to your motherboard.
2. You can use a PCMCIA network card which is about $20-30. Insert this card into the PCMCIA port on the laptop and you get another eithernet port on the card.
3. Replace the motherboard.
June 6th, 2009 at 11:50 pm
i have a dell m1530 and its ethernet port is busted is it possible to replace the ethernet port in this ? or will i have to replace the whole motherboard?
May 19th, 2009 at 7:26 am
phil,
Apparently the water went down to the motherboard and damaged it. It’s necessary to disassemble the laptop and take a closer look at the damage. Most likely you’ll have to replace the motherboard.
May 18th, 2009 at 10:32 pm
turns out the other day, accidently got water into my laptop..i let it dry and was able to get it working, it worked for about an hour till it cut off. now i’m able to charge and start it up, but nothing seems to be showing on the screen. i hear the computer running but seems to stop making any noises after about 15 seconds. help me out?
May 9th, 2009 at 4:32 pm
Manda Yugana,
It’s hard to tell what’s going on. I don’t know what they did with the AC adapter, maybe it’s not working properly. The only way to find out is testing the laptop with another known good AC adapter. If you still have the same problem, there is something wrong with the motherboard.
You can find a new AC adapter for your laptop if Google one of the following part numbers: K000037400, K000041650, K000040330, K000043540. The all work with Satellite M105 laptops.
May 9th, 2009 at 4:07 pm
Repair Man : Did they repair or replaced the adapter. I don’t think that you can repair this adapter because it’s sealed unit. The adapter is not designed to be repaired.
Manda : They repaired and resealed it. Some capacitors replaced and small part of circuit removed.
Repair Man : Did this light work before they repaired the adapter?
Manda : Yes, the light worked before and sometimes after. But then it didn’t work at all.
Repair Man : Does it actually charge the battery when the laptop is turned off (even though the power indicator light is off)?
Manda : No, even though there is electricity in laptop’s metal part (I test it with a test pen).
Repair Man : Can you start the laptop from the AC adapter when the battery is removed?
Manda : Here’s the detail.
1. If I plug the adapter when the laptop is turned off (w/ or w/o battery), it doesn’t work (and doesn’t charge the battery)
2. If I turn on the laptop (w/ battery) then plug the adapter, it works (and also charges the battery)
3. No (2) + then turn the laptop off, the battery will be charged.
4. No (2) + then remove the battery, the laptop will remain on.
It looks like the adapter needs a “help” from the laptop power to work. After the laptop is turned on, everything works fine.
May 9th, 2009 at 9:59 am
Manda Yugana,
Did they repair or replaced the adapter. I don’t think that you can repair this adapter because it’s sealed unit. The adapter is not designed to be repaired.
Did this light work before they repaired the adapter? Does it actually charge the battery when the laptop is turned off (even though the power indicator light is off)?
Can you start the laptop from the AC adapter when the battery is removed?