Curious Ram Issue

Tismichael · 06-27-2009, 12:51 AM

I have a Toshiba Satellite A135-2356 with a curious RAM problem.
The computer originally came with 512MB of RAM and I upgraded it to 1.5G of RAM by adding a 1G stick. This has worked fine until now.
I purchased another 1G stick, removed the 512MB stick, and added the new 1G stick. The computer only recognizes one of the sticks.
I tried moving the sticks from 1 slot to the other but only 1 stick is recognized
Individually they work fine but together they do not.
I put the 512MB back and the computer is reading 1.5GB of RAM which is correct but for whatever reason when the new 1G stick is put in, it is not recognized and the computer is reading only 1G of ram available.
The computer is running Vista Home Basic and has the Celeron M processor.

Does anybody have any ideas as to why the 1G stick is not recognized when added but the 512MB stick is?

**grimx133** · 06-27-2009, 01:46 AM

According to crucial, your laptop does take the 2x1GB for a max. http://www.crucial.com/store/listpar...e%20A135-S2356

Usually memory is added by using matched pairs, when you mix ram, the result is always uncertain. It is also always a good idea to use the ram manufacturer's configurator, then buy the exact part number, either from them or elsewhere. That way the ram is guaranteed to work, some motherboards are pickier than others at what goes in the memory slots.

Stu_computer · 06-27-2009, 07:17 AM

Satellite A135 is max 2Gb, part number PSAD6U-01800G (PC2-4200 533MHz DDR2)

disconnect ac adapter, remove battey, press power_on button for 20 seconds then install new modules. replace battery, connect ac adapter and power on.

question: what are the specs for the modules you are using?

Tismichael · 06-28-2009, 03:28 PM

Both of the RAM sticks were purchased from the Kingston website directly.
They are both the Kingston KTT533D2/1G types of memory. The sticks were purchased at different times but are of the same manufacturer and size.

I will try Stu's suggestion. I always take the AC adaptor out and disconnect the battery prior to removing any of the panels off the bottom of the laptop but I have never heard of pushing the power button for 20 seconds after removing the power supplies.
When I get a chance to do this I will let you know what happens.

I have also heard that you can add more RAM than what is recommended for the slots. Is this a computer that you can do that with? I would like to be able to get at least 3G of ram installed because of Vista.

**Tyree** · 06-28-2009, 04:34 PM

2GB, 1GB max per slot, four your Laptop.

Stu_computer · 06-28-2009, 07:45 PM

toshiba, kingston, and crucial sites list the a135 as 2Gb max (not to be exceeded) so don't waste your money.

first, the memory controller in the northbridge chip determines size and type of ram that can be used, (newer versions of the chipset usually can handle more ram--that's why it's often confusing what the maximum limit is for a mobo).
second, how the mobo manufacturer hardwires the board may reduce that maximum limit.
third, how the bios is written to manage ram may further impact how much is usable, (sometimes bios fix/upgrades improve performance and allow more ram.)

typically, a laptop will have lower ram limit than the desktop version.

06-27-2009, 12:51 AM	#1 (permalink)
Tismichael Registered User Join Date: Jun 2009 Location: Colorado Posts: 2 OS: Vista Home Basic	Curious Ram Issue I have a Toshiba Satellite A135-2356 with a curious RAM problem. The computer originally came with 512MB of RAM and I upgraded it to 1.5G of RAM by adding a 1G stick. This has worked fine until now. I purchased another 1G stick, removed the 512MB stick, and added the new 1G stick. The computer only recognizes one of the sticks. I tried moving the sticks from 1 slot to the other but only 1 stick is recognized Individually they work fine but together they do not. I put the 512MB back and the computer is reading 1.5GB of RAM which is correct but for whatever reason when the new 1G stick is put in, it is not recognized and the computer is reading only 1G of ram available. The computer is running Vista Home Basic and has the Celeron M processor. Does anybody have any ideas as to why the 1G stick is not recognized when added but the 512MB stick is?

06-27-2009, 01:46 AM	#2 (permalink)
grimx133 Mentor Hardware Team Join Date: Jan 2008 Location: Canada eh Posts: 3,138 OS: xp mce sp2, xp pro sp2, windows 7 beta My System	Re: Curious Ram Issue According to crucial, your laptop does take the 2x1GB for a max. http://www.crucial.com/store/listpar...e%20A135-S2356 Usually memory is added by using matched pairs, when you mix ram, the result is always uncertain. It is also always a good idea to use the ram manufacturer's configurator, then buy the exact part number, either from them or elsewhere. That way the ram is guaranteed to work, some motherboards are pickier than others at what goes in the memory slots. __________________

06-27-2009, 07:17 AM	#3 (permalink)
Stu_computer Tech Hardware Team Join Date: Jul 2005 Posts: 1,459 OS: Windows	Re: Curious Ram Issue Satellite A135 is max 2Gb, part number PSAD6U-01800G (PC2-4200 533MHz DDR2) disconnect ac adapter, remove battey, press power_on button for 20 seconds then install new modules. replace battery, connect ac adapter and power on. question: what are the specs for the modules you are using? __________________

06-28-2009, 03:28 PM	#4 (permalink)
Tismichael Registered User Join Date: Jun 2009 Location: Colorado Posts: 2 OS: Vista Home Basic	Re: Curious Ram Issue Both of the RAM sticks were purchased from the Kingston website directly. They are both the Kingston KTT533D2/1G types of memory. The sticks were purchased at different times but are of the same manufacturer and size. I will try Stu's suggestion. I always take the AC adaptor out and disconnect the battery prior to removing any of the panels off the bottom of the laptop but I have never heard of pushing the power button for 20 seconds after removing the power supplies. When I get a chance to do this I will let you know what happens. I have also heard that you can add more RAM than what is recommended for the slots. Is this a computer that you can do that with? I would like to be able to get at least 3G of ram installed because of Vista.

06-28-2009, 04:34 PM	#5 (permalink)
Tyree Mentor Hardware Team Join Date: May 2009 Location: Illinois Posts: 5,540 OS: XP Pro-7RC-Mandriva My System	Re: Curious Ram Issue 2GB, 1GB max per slot, four your Laptop. __________________ Posting your PC specs will help us to help you quicker and more efficiently.

06-28-2009, 07:45 PM	#6 (permalink)
Stu_computer Tech Hardware Team Join Date: Jul 2005 Posts: 1,459 OS: Windows	Re: Curious Ram Issue toshiba, kingston, and crucial sites list the a135 as 2Gb max (not to be exceeded) so don't waste your money. first, the memory controller in the northbridge chip determines size and type of ram that can be used, (newer versions of the chipset usually can handle more ram--that's why it's often confusing what the maximum limit is for a mobo). second, how the mobo manufacturer hardwires the board may reduce that maximum limit. third, how the bios is written to manage ram may further impact how much is usable, (sometimes bios fix/upgrades improve performance and allow more ram.) typically, a laptop will have lower ram limit than the desktop version. __________________ Last edited by Stu_computer; 06-28-2009 at 08:02 PM.