Added 2 1gb pc2-6400 240 pin ddr2 800 memory modules in my am1100-e1401b in the 2 extra spots compters shuts down swapped them out with existing 512 mb cards then it seems to work fine but only end up with 2gb instead of 3

The PSU might be faulty "Power Supply Unit"
try these following troubleshoot options, use a different power cable, make sure the power is turned on on the back of the computer if the same problem is still there then you will need to buy a new power unit from most computer stores.

just leave in one of the new 1gb stick of memory
if stable memory was the issue so add the back one at a time each time shut down install turn on test
if still unstable coould be the hard drive

Hi there, you should purchase memory with same speed. say, if your existing memory is a 512 DDR2 667mhz memory module. what you will buy is 1024 DDR2 667mhz memory module also. memory with different speed can have conflicts on the system. thanks!

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Swap the modules between the slots.

If the message shanges to slot 0 not recogonized, then you have a bad memory module,
Easy fix, just get another module.

If the message does not change, then you have a problem on the mother board.
Not an easy fix, it would be cheaper to buy a 1GB module and use the good slot.

Good Luck!

Hi four short beep codes generally means faulty ram in the first position. If the old RAM was working fine, then try using it in the other slot and see what happens. You may have damaged a pin installing the RAM, if it works in the other slot, remove it and inspect the damaged slot with a magnifying glass and see if you can spot a bent or missing pin.

Let me know how you make out,

Chris

Are you sure its the correct speed/type of RAM? According to Google your laptop takes PC2700 DDR RAM, ensure you are using this in both slots to avoid problems. If you have it fully inserted into the slot and nothing happens when you swtich it on then the laptop doesnt like that type of RAM and you'll need to change it.

Try Acers website first and then try driverguide.com

Step 1: Find the memory type and amount used by the computer
Step 2: Find out how much memory can be added
Use the following steps to find out how much memory is currently installed and how much can be added:
Open My Computer .
In Microsoft Windows XP, click Start and right-click My Computer .
In Windows 98 and Me, right-click My Computer .
Select Properties and then click the General tab if not already selected (see Figure 1).
Subtract the amount of RAM currently in the computer from the maximum amount of memory the computer can hold. This is the amount of RAM that can be added. For example, in the figure below, the computer has 192 MB of RAM. If the maximum amount of memory the computer can hold is 512 MB, then 320 MB is the amount of RAM that can be added.
Divide the maximum amount of memory that the computer can hold with the number of memory sockets on the motherboard. Usually, this is the maximum amount for each memory socket. For example, if the computer is capable of holding a maximum of 1024 MB (1G) of memory and the motherboard has four memory sockets, it would be safe to install nothing higher than a 256 MB memory module in each socket.

Step 3: Remove memory
Use the following steps to remove a memory or continuity module:
Turn off the computer.
Windows 98 or 2000: Click Start , Shut Down , and then Shut Down
Windows XP: Start and then Turn Off .
Unplug the AC adapter, if present, and remove the battery.
From the bottom of the computer, remove the screw holding the RAM cover, and remove the cover.
Spread the retention clips on each side of the memory expansion board.
WARNING: To protect a removed memory expansion board, place it in an electrostatic-safe container.
Remove the board by pulling it away from the connector at a 45-degree angle.
Step 4: Add a memory module
Use the following steps to increase the computer's RAM, install a RAM module in the expansion slot on the bottom of the computer.
CAUTION: The computer's chips are extremely sensitive to static electricity, and can be permanently damaged by it. Handle the RAM module only by its edges. Before installing the memory module, discharge the body's static electricity by touching the metal shielding around the connectors on the rear of the computer.
Turn off the computer.
Windows 98 or 2000: Click Start , Shut Down , and then Shut Down
Windows XP: Start and then Turn Off .
Unplug the AC adapter, if present, and remove the battery.
From the bottom of the computer, remove the screw holding the RAM cover, and remove the cover.
Align the keyed (notched) edge of the board with the keyed area in the expansion slot. Insert the board into the slot at a 45-degree angle until it is seated.
Push the front edge of the board down until the retention clips snap into place.
Replace the cover.
Insert the battery.
NOTE: Windows 98 only: When increasing the computer's memory to more than 512 MB, the computer will not be able to hibernate unless the size of the utility partition on the hard disk is also increased.
Step 5: Test the memory
Turn on the computer. If the computer does not start properly, go to the next section Troubleshooting memory problems .
The memory test should briefly run when the computer restarts. Restart the computer several times to make sure that the memory works properly.
If the memory count fails to complete, stops before reaching the total amount of memory, or counts more than once in consecutive restarts, troubleshoot the memory problem or replace the new memory module with another memory module.

Troubleshooting memory problems

Try the following items if the computer cannot start or has memory errors (including beeps) when the computer first starts:
Remove the new memory module and clean the groove in the socket that the module sits in. Use a can of compressed air with a straw-type extender and safety glasses.
Re-seat the new memory module by repeating Step 2 through 5 of this document.
Make sure that other cables inside the computer are not partially out of their sockets. Reseat any cables that are dislodged.
Replace the new memory module with a different one. Make sure that the memory is the right type and compatible size of memory. You can remove and reference from the memory module that originally came installed in the computer.
still if you face any issues
please do not hesitate post the issue
in detail
i will guide you more in step by step

Thanks

It sounds like something isnt working right, what operating system are you using, Vista? I would take out the original 512 and see what it says after, often ram isnt compatible if it is too different in size and speeds. Also, if your motherboard supports dual channel ram and you have the extra 512 chip it wont run in dual channel mode, you would run better with just the 2 chips then the added 512 chip.

For this mainboard, you must use 168-pin, 3.3V unbuffered PC100 or PC133 SDRAM memory modules. You can install any size memory module from 32 MB to 512 MB, so the maximum memory size is 2 x 512 MB = 1 GB. As noted on pg. 9 of your manual. Shut down your system. Remove one dimm of memory & start the Pc. Does it boot & do you have video? No? Shut down & replace the the dimm with next stick of memory. Try again. Still no video? Replace memory with old memory. Did you regain video? In most cases of installing new memory it's found the memory just wasn't seated well enough. In few others the memory did not meet the correct voltage.
prazum post back your findings.