DIAGNOSING THE MOST COMMON MEMORY PROBLEMS

Memory sizing error during POST [Power On Self Test - initial system boot]
You computer will not boot-up even in DOS
General POST BEEP Codes
American Megatrends Inc. (AMI) BEEP Codes
Award BEEP Codes
Phoenix BEEP Codes
Basic Trouble Shooting

Memory sizing error during POST (initial system boot)

This is one of the more common memory problems, occurring mainly in older computers.
A "memory sizing" error may occurs in older computers of the 486 and early Pentium types. It involves systems using SIMM modules and the addition of more modules, or the replacement of old modules with new but with an increase in the total amount of memory. This increase in memory causes a problem with the BIOS on the motherboard as the BIOS recalls the old amount of memory and must be adjusted to reflect the new amount as well as any memory parameter changes. To adjust the values in the BIOS settings, boot the system into the BIOS menu (you should have the manual for you motherboard to do this), make the adjustments, and then save the settings. Pentium, Pentium Pro and Pentium II do not normally have memory sizing errors. If it happens at all, the first place to check would be the motherboards BIOS settings. The next place to look would be the modules themselves. Check and verify that all modules are alike and that the parameters of the memory modules are supported by the motherboard, especially issues such as parity versus non-parity and ECC (error correcting code) support. Later Pentiums, those motherboards with the GX, LX, BX and 800 series chipsets (with auto recognition), are not normally susceptible to this problem. On those motherboards that permit the user to modify all BIOS settings, it is possible to see a memory sizing error, but in only those situations where the user has the ability to set the BIOS to a predetermined memory amount and auto-recognition has been disabled. Later machines are more apt to see parity errors, ECC errors and poor performance due to a mismatch of memory types, such as those experienced with poor quality memory modules.

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You computer will not boot-up even in DOS

There are several possible causes for this to occur. Here are some of the possibilities you may want to check.
• Computer power supply is failing or has failed.
• Motherboard failure, including the on-board voltage regulator.
• The processor has overheated due to a fan failure or a prior overheat condition has damaged he processor.
• Video card failure.
• Lightening strike or power spike damage to your telephone line has damaged the modem, which is causing the ISA or PCI bus to fail.
• Floppy drive, hard drive or CD-ROM drive failure is causing a system electrical short.
• Memory module failure.
Initial Testing Procedure: Disconnect everything from the motherboard except the power supply connection, processor and memory and try to start the system and listen for beep tones. Count the beep tones and then refer to your owners manual. If there is a memory error, you will receive the appropriate beep tones. Add back one component at a time until you discover the cause of the problem.

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General POST (initial system boot) BEEP Codes

If you do not know the BIOS manufacturer, the following will be the general Beep codes:

• 1 Long and 1 Short Beep – Bad Motherboard
• 1 Short Beep and nothing else happens – Disk Drive/Video Related Problems
• 1 Long and 2 Short Beeps – Bad Video Card
• 1 Continuous Beep or Non-stop short Beeps – Bad Power Supply
• 3 Short Beeps - Bad Memory

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American Megatrends Inc. (AMI) BEEP Codes

• 1 Beep - Memory refresh timer error.
Reseat the memory, or replace with known good modules.
• 2 Beeps – Parity Error
Reseat the memory, or replace with known good modules.
• 3 Beeps - Main memory read / write test error.
Reseat the memory, or replace with known good modules.
• 4 Beeps - Motherboard timer not operational
• 5 Beeps - Processor Errors
• 6 Beeps - Keyboard controller BAT test error.
• 7 Beeps - General exception error.
• 8 Beeps - Display memory error.
If the system video adapter is an add-in card, replace or reseat the video adapter. If the video adapter is an integrated part of the system board, the board may be faulty.
• 9 Beeps - ROM checksum error
• 10 Beeps - CMOS shutdown register read/write error
• 11 Beeps - Cache Memory Bad

Beeps 4-7, 9-11
Fatal error indicating a serious problem with the system. Consult your system manufacturer.

Before declaring the motherboard beyond all hope, eliminate the possibility of interference by a malfunctioning add-in card. Remove all expansion cards except the video adapter.
§ If the beep codes are generated even when all other expansion cards are absent, the motherboard has a serious problem. Consult your system manufacturer.
§ If the beep codes are not generated when all other expansion cards are absent, one of the add-in cards is causing the malfunction. Insert the cards back into the system one at a time until the problem happens again. This will reveal the malfunctioning add-in card.

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Award Bios BEEP Codes

• 1 Long Beep: Memory problem
Explanation: There is a failure of some sort related to the system memory.
Diagnosis: The first bank of memory probably has a failure of some sort; this is usually just a physical problem such as an incorrectly inserted module, but may also mean a bad memory chip in a module. It is possible that there is a failure related to the motherboard or a system device as well.

• 1 Long, then 2 Short Beeps: Video error
Explanation: The BIOS is unable to access the video system in order to write any error messages to the screen.
Diagnosis: This is usually caused by a problem with the video card, or the memory on the video card. It can also be a motherboard issue.

• 1 Long, then 3 Short Beeps: Video error
Explanation: The BIOS is unable to access the video system in order to write any error messages to the screen.
Diagnosis: This is usually caused by a problem with the video card, or the memory on the video card. It can also be a motherboard issue.

• Continuous Beeping: Memory or video problem
Explanation: The system is producing constant beeping in no specific pattern, or a fast "ringing" sound.
Diagnosis: This is usually caused by a problem with the system memory, or possibly the video card. The memory is more likely--the system complains long and loud if it can't find any usable memory, as there is no way to even start the boot process when this is the case. The motherboard itself could also be the problem.

• Other Beep Codes
Explanation: You have encountered an Award BIOS beep code I do not have documented.
Diagnosis: Award says that any beep patterns other than "one long followed by two short" are likely problems with the system memory. However, of late they have started adding other beep codes to their systems as well.

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Phoenix BEEP Codes

• 1-1-3
Explanation: Your computer can't read the configuration information stored in the CMOS.
Diagnosis: Replace the motherboard.

• 1-1-4
Explanation: Your BIOS needs to be replaced.
Diagnosis: Got to your motherboard manufacturers web site and download the new Bios.

• 1-2-1
Explanation: You have a bad timer chip on the motherboard.
Diagnosis: Replace the motherboard.

• 1-2-2 or 1-2-3 or 1-3-1 or 1-3-3 or 1-3-4 or 1-4-1
Explanation: Motherboards is bad.
Diagnosis: Replace the motherboard.

• 1-4-2
Explanation: Some of your memory is bad.
Diagnosis: Go to Basic Trouble Shooting

• 1-3-1
Explanation: Motherboards is bad.
Diagnosis: Replace the motherboard.

• 2-_-_ Any combination of beeps after two
Explanation: Some of your memory might be bad.
Diagnosis: Go to Basic Trouble Shooting

• 3-1-_
Explanation: One of the chips on your motherboard is broken.
Diagnosis: Replace the motherboard.

• 3-2-4
Explanation: Keyboard controller failure.
Diagnosis:

• 3-3-4
Explanation: Your computer can't find the video card.
Diagnosis: Is it there? If so, try swapping it with another one and see if it works.

• 3-4-_
Explanation: Your video card isn't working.
Diagnosis: Replace Video Card

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Basic Trouble Shooting

When you have a problem with memory, the cause is usually one of these: Improper Configuration, Improper Installation, Defective Hardware.
The following basic steps apply to almost all situations:

1. Make sure you have the right memory part for your computer. If you have used the memory configurator and have selected a memory for the “correct” model than the problem might be somewhere else. If you have selected a standard memory module, you must make sure the module you have selected is compatible with your system.

2. Confirm that you configured the memory correctly. Many computers require module installation in banks of equal-capacity modules. Some computers require the highest capacity module to be in the lowest labeled bank. Other computers require that all sockets be filled; still others require single-banked memory. If you are in doubt contact Technical Support by emailing TechSupport@memory.com.

3. Re-install the module. Push the module firmly into the socket. In most cases you hear a click when the module is in position. To make sure you have a module all the way in the socket, compare the height of the module to the height of other modules in neighboring sockets.

4. Swap modules. Remove the new memory and see whether the problem disappears. Remove the old memory, reinstall the new, and see whether the problem persists. Try the memory in different sockets. Swapping reveals whether the problem is a particular memory module or socket, or whether two types of memory aren't compatible.

5. Clean the socket and pins on the memory module. Use a soft cloth to wipe the pins on the module. Use a PC vacuum or compressed air to blow dust off the socket. Do NOT use solvent, which may corrode the metal or prevent the leads from making full contact. Flux Off is a cleaner used specifically for contacts. You can purchase it at electronics or computer equipment stores.

6. Update the BIOS. Computer manufacturers update BIOS information frequently and post revisions on their Web sites. Make sure you have the most recent BIOS for your computer. This applies especially when you have recently installed new software or you are significantly upgrading memory.

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