Memory also known as RAM
A laptop memory also know as RAM (Random-access memory) is a temporary data storage. It’s a volatile type of memory. When you turn off the laptop, all the information stored in a RAM module is lost.
More memory installed into your laptop gives you a better (faster) performance.
You can test laptop memory with a free diagnostic tool called Memtest86+.
A type of memory used in laptop computers called SO-DIMM (Small Outline Dual In-line Memory Module).
Here are three most common memory types found in laptop computers:
1. SDRAM SO-DIMM memory has 144pins.
PC100 modules running at 100MHz.
PC133 modules running at 133MHz.
PC133 modules are backward compatible with PC100 modules.If your laptop requires a PC100 memory module, you can safely use a PC133 module but it will run at PC100 speed.
2. DDR SO-DIMM memory has 200 pins.
PC2100 (DDR266) modules running at 266MHz.
PC2700 (DDR333) modules running at 333MHz.
PC2700 memory is backward compatible with PC2100 memory. If your laptop requires a PC2100 module, you can safely use a PC2700 module but it will run at PC2100 speed.
DDR memroy modules are not backward compatible with SDRAM modules.
3. DDR2 SO-DIMM memory has 200 pins.
PC2-3200 (DDR2-400) running at 200MHz.
PC2-4200 (DDR2-533) running at 266MHz.
PC2-5300 (DDR2-667) running at 333MHz.
PC2-6400 (DDR2-800) running at 400MHz.
Faster DDR2 memory modules are backward compatible with slower DDR2 memory modules. For example, if your laptop requires a PC2-4200 memory module you can safely use a PC2-5300 module but it will run at PC2-4200 speed.
DDR2 memory modules are not backward compatible with DDR modules. The notch on DDR2 is located in a different position from DDR.
WHERE MEMORY MODULES ARE LOCATED.
In a laptop computer memory slots could be found in a few different locations, it depends on the brand and model of the laptop.
1. Both memory slots can be accessed from the door on the bottom.
2. One slot is located on the bottom and another one under the keyboard.
3. Both memory slots are located under the keyboard.
4. There is only one memory slot available for upgrades. The main memory is integrated into the motherboard.
HOW TO REMOVE MEMORY MODULE FROM THE SLOT.
Step1.
Release latches on both sides from the memory module with your fingers.
Step2.
The memory module will pop up at a 20-30 degree angle.
Step3.
Carefully pull the memory module from the slot by the edges.
WHAT YOU NEED TO KNOW BEFORE BUYING LAPTOP MEMORY.
1. You are looking for SO-DIMM memory used in laptop computers.
2. Type of the memory used in your laptop: SDRAM, DDR, or DDR2.
3. How many memory slot are available.
4. How much memory your laptop can handle.
Laptop parts | Repair Man | 
December 25, 2008 5:33 pm
November 2nd, 2011 at 4:06 pm
@ akinyode,
The notch is located in a different spot. You cannot install DDR memory into DDR2 or DDR3 slot.
June 1st, 2011 at 10:22 pm
please, what is the difference between ddr1 and ddr2, hence a diagram illustration required
February 1st, 2011 at 8:02 am
haider,
Yes, you can use different size modules in different slots. If you use 1GB in one slot and 512MB in the second slot, you’ll get 1.5GB RAM total.
No, you cannot use DDR2 memory in a laptop designed for DDR memory.
DDR and DDR2 modules are different. A new DDR2 modules will not fit into DDR slot because it has a notch located in a different spot.
In your ThinkPad T42 laptop you can use only DDR PC2700 memory modules.
January 31st, 2011 at 1:01 pm
I have a T42, it has 1Gb(two 512M) ram, I want to upgrade it.
Is it possible to
a– use 1Gb and 512Mb ram combination PC2700 (DDR333) modules running at 333MHz.
b– use 1Gb or 2Gb(one ram only) PC2-3200 (DDR2-400) running at 200MHz or PC2-5300 (DDR2-667) running at 333MHz.
Will I get more speed with option ‘b’.
January 28th, 2011 at 11:30 pm
David,
I can help to find out how much memory it takes if you provide the laptop model number.
January 27th, 2011 at 6:56 am
please how can i know how many memory my laptop can carry?
December 11th, 2010 at 8:44 pm
what is the possible problem if a laptop turns on but after about 3 seconds the cpu fan will turn off but the computer still have the power light
November 10th, 2010 at 7:19 am
Hi, i have a packard bell laptop with model number (easynote PB32R00101) and i really need the drivers. Can you be of help. Thanx
October 10th, 2010 at 5:54 pm
In response to #39, the Closing Bracket key is this:’ ] ‘ , he wants to know how much for another plastic piece with the ]} symbols on it, or the response part on the keyboard may be damaged?
October 5th, 2010 at 1:58 pm
Dipankar,
What is closing bracket key?
September 18th, 2010 at 10:15 pm
I have compaq presario-V5000, its closing bracket key is not working, I want to know that how much cost will be to repair the key.
Dipankar.
August 16th, 2010 at 9:25 pm
repairman,
What? Your question is not clear.
Did you try reconnecting memory? Did you test your laptop with only one memory module installed?
August 13th, 2010 at 6:34 pm
what is the problem if a loptop turns on but it will off and after a while turn off?..
July 29th, 2010 at 9:24 pm
shankar lal,
HCL Leaptop K38-MTV?
I found this site: http://www.india-server.com/laptops/features/hcl-leaptop-k38-mtv-30.html
It says 8GB is max.
July 25th, 2010 at 5:33 am
i have laptop hcl k38.how can i install 16GB ram in laptop.
February 20th, 2010 at 8:41 pm
kelvin lo,
If you turn on a laptop without RAM modules installed, you’ll get one of the following:
1. The laptop will turn on but the screen will stay black.
2. The laptop will turn on and start beeping.
3. The laptop will turn on and after a while turn off.
February 20th, 2010 at 8:34 pm
if my laptop doesn`t have ram installed inside can the laptop switch on?
November 5th, 2009 at 1:26 pm
Gregory Day,
I don’t know. You’ll have to try because it might work. I’ve done it before a few times.
You may choose to repartition and reformat the hard drive while installing Windows from scratch.
November 5th, 2009 at 1:24 pm
Gregory Day,
You can use either slot.
November 4th, 2009 at 2:20 pm
I was given a Thinkpad T42p 2373 w/out a hard drive in it and no recovery disk. Can I install a hard drive that has been cloned from a T52 2888 then update it from Lenovo’s website with the T42p drivers or am I going to have to load a fresh install of XP Professional and then update from Lenovo website. Also if I can’t use the data on this HDD how do I wipe out the T52 data on the cloned HDD to use it or when I load the the new OS it will be done automatically. I’m just really trying to see if the laptop is anygood, the person I got it from didn’t know. Thanks
November 4th, 2009 at 2:09 pm
I was given a IBM Thinkpad T42p 2373, this laptop has no ram installed in it, in the bottom slot or the slot under the keyboard. I have 1 stick of 512 PC2700 sodimm out of a T51, my question is can I install it in the bottom slot or do I have to install it in the slot under the keyboard for the laptop to work? I’m only going to install one dimm since I only have one.
Thanks.
July 6th, 2009 at 10:13 pm
Madeline,
I don’t think so. When your laptop doesn’t have enough RAM it slows down, but should get any BSOD error.
It’s possible that you have a hardware related problem.
You have two memory modules installed into the laptop, right? Can you remove them one by one and test the laptop with each module separately. Can you boot the laptop when only one of the modules is installed? If you can, most likely the other module is bad.
If your laptop fails to boot with either module installed, apparently it’s not memory related issue. It’s very unlikely that both memory modules fail at the same time.
Try removing them one by one first.
July 6th, 2009 at 9:55 pm
Hi, I have a acer aspire 5100 laptop. The harddrive was packed to capacity and was running slow and would would freeze up, especiall y when using large size software. When trying to burn off some of my files unto cds to free up some space the system frozed. I had to take it off manually. Later when I turn it back on it booted up to the windows splash screen then restarted, and it kept doing that over and over. Could not enough memory [RAM] cause this problem. The harddrive seem to be running smoothly without any unusal noises. Also I was able to get into the BIOS, but it won,t start in safe mode or any other option. Won’t boot from the cd, so I tried reinstalling the OS, not reformatting it, [I'm trying to save my data]. that didn’t work either. I got a BSOD though. It said : STOP:0x0000008E(0xC0000005, 0xF7802CAD, 0xF73C47E4, 0×00000000] setupdd.sys- Address F7802CAD base at F77D6000 Date stamp 41107c8f. Could this mean that I need more RAM? Any help will be appreciated.
June 2nd, 2009 at 7:44 am
A clear and concise summary mate. Good job on the article.
April 22nd, 2009 at 8:12 am
tbrandis,
Yep, sounds like a problem with the motherboard.