Troubleshooting Memory

Using Beep codes

The BIOS on the motherboard will always perform a power-on-self-test “POST” during power up, usually this test is perform to ensure proper system function and if a failure occurs – the “POST” will identify the failure and emits a beeping sound to prompt the service technician to take corrective action ASAP.

The exact meaning of the beeping codes varies from different BIOS developers, there are 3 basic BIOS developer today, the most popular BIOS is made by “American Mega-trend” - AMI, Award and Phoenix BIOS. The beep codes for this AMI & Award BIOS developer are provided in this memory troubleshooter guide, we do not provide beep code reference for Phoenix BIOS and custom BIOS written by other companies other than the two mention.

Beep codes are not entirely consistent sometimes to detect the exact failures, but generally it is still the most dependent methods to diagnose a fault without opening up the PC system or using any diagnostic software

Awaard BIOS

Award is the another popular BIOS developer and they use the fewest beep codes by far.

Procedures – The normal procedure is to power up the PC system, watch for error message on the monitor screen and listen to the PC beep tone. A single beep during boot-up process is normal and does not indicate a failure if the system continues to boot-up.

1 Long Beep tone - Memory Problem
1 Long Beep and 2 Short Beeps - DRAM Parity failure 
1 Long Beep and 3 Short Beeps - Video error 
Continuous Beep tone - Memory or Video memory failures

System hangs

Well, this is tricky situation. Typically you may want to begin by finding out if it's a memory related problem. 

If I have regular memory sizing error during POST (bootup), how should I trouble shoot the failure ? A One of the most common memory problem faced in older PC system during boot-up is “incorrect memory sizing” or the error number 164. Sometimes failures could be caused by incorrect software setting, sometimes it could be caused by hardware – which could be easily fixed if you know where the faults lies.

In most cases hardware failures are caused by the natural aging process of the memory components, defective memory module socket, dirty contacts, cold solder joints during assembly and memory module not seated properly in the socket due to vibration.

It is important to pay attention to intermittent memory failure, before you make any expensive decision to replace the expensive memory - try cleaning the memory module contacts for both old and new ram to see if the problem can be fix:

Here ‘s the How to :

Things needed – Contact Clean (Purchase from local computer hardware store) - Cotton Bud ( For cleaning contact with) - Screwdriver (pc case removal) - PC user manual

1 - ensure environment is static safe by removing any unwanted plastic, bags from your workbench. Keep the computer system plugged into your AC unit but ensure that the power switch on the PC is turned off. Keeping the PC plugged in the AC will ensure that case is grounded thus reducing the possibility of damaging the module or system from ESD (Electro Static Discharge)

2 -After removing the casing cover, ground yourself by touching any of the metal surfaces on your computer casing. Doing this step discharges any static built up on your body and clothing

3 - Visually locate the computer memory expansion slots. This is normal visible but if in doubt, refer to your operation manual instruction book.

4 – the first thing to do is to remove the memory module and perform some visual inspection to check the memory socket which sits the memory module. Make sure all the pins are straight, no cracks or broken pins must be found.

A Wet the end of a cotton swab with the solvent, the swab should be wet but not dripping B Using a circular motion, clean the contacts on the memory module. C Allow the contact surface to dry thoroughly. D Replace the memory module into the socket. E Repeat steps B through D for each module you have. F Power on the computer to test the RAM. G If you see no memory errors, replace the PC's case and power-up away.

Additional Tips:

5. While contact cleaner is preferred, it is also a well-known trick that you can also clean contacts with a pencil eraser. 6. Continuing RAM errors are usually a sign of a bad memory module. If cleaning the contacts doesn't solve your problem, try to isolate the faulty module and replace it.

Without memory tester

You can attempt the following experiment- : 
A Removing the modules one by one from motherboard. This is simplest method for isolating a failing module, but this may apply only if the motherboard have more than one module on the SIMM or DIMM Slot. By selectively removing module one at a time from the system and then running the test you will be able to find the bad module very quickly. Be sure to mark the module that passes or when it test fails.

Swap the modules around . When none of the modules can be removed, swap and rotate modules to find which module is defective. This technique can only be used if there are two or more modules in the system. Change the location of two modules one at a time.

For instances, place the module from SIMM slot 1 into slot 2 and place the other module from slot 2 in slot 1. Run the diagnostic test and if either the failing data bit or address changes, you know that one of the module you have just swap is defective. By using several combinations of module swapping you should be able to check which module is defective.

Replacing with known good module. If you are unable to use either of the above two techniques, you are left to use known good modules and selectively replace of modules one by one to pin point the memory failure. This is the easiest way to detect memory failure.

Removing and cleaning the metal contacts. If your PC system is older, sometimes dust and oxidation will cause poor contact in the SIMM/DIMM slot. Remove the module and clean the gold or tin contact with a “pencil eraser” or any cleaning solution used for video and audio head cleaning. Make sure you remember which slot is being used, and be careful not to reverse the module while reinserting into the SIMM/DIMM slot

Identifying memory failure using motherboard BIOS codes. If you are not trained to perform the correct diagnostic methods – majority BIOS developers and motherboard manufacturers have device a simple way of telling you if your system is having problem by emitting beeping tones from the build in speaker on the motherboard, without the aid of a memory tester.

When you are experiencing memory failures on your PC system, there are several faults to determined, check the following:

* PC system does not boot-up * HIMEM.SYS does not load * Memory failure due to system hanging up, or system rebooting after running a large program. * Fail to install win3.1, Win95 and Win98 * Windows program is unstable * Continuous beeping sound emitted by system during power up * Continuous ram count during boot-up , without loading Windows program * No display other than blue screen on the monitor during boot-up * Totally no video display on the monitor. * System hang or rebooting after prolong usage.

All of the above are typical of memory related failures, you need to be either well trained or PC knowledgeable to be able to perform the correct diagnostic methods.

Once a memory failure has been detected, identifying the defective module is not an easy task either. With a large variety of motherboard provided by different manufacturer around the world, and with the many different combination of SIMM/DIMM slots provided, it would be difficult if not impossible to assemble a complete information about how a particular memory error would map to a failing memory module.

However, there are some basic rules that may be taken to pinpoint defective modules using a memory diagnostic software as an aid.

AMI BIOS

AMI BIOS is the most popular BIOS used by most motherboard manufacturer- you should be able to determine your system BIOS by reading the screen display on the Top screen during power up.

Procedures – The normal procedure is to power up the PC system, watch for error message on the monitor screen and listen to the PC beep tone. A single beep during boot-up process is normal and does not indicate a failure if the system continues to boot-up.

1 Beep tone - DRAM refresh failure 
2 Beep tone - DRAM Parity failure
3 Beep tone - Base 64K RAM failure
4 Beep tone - System timer error 
5 Beep tone - CPU failure 
6 Beep tone - Keyboard controller error 
7 Beep tone - Virtual mode error 
8 Beep tone - Display memory read/write error 
9 Beep tone - ROM BIOS checksum error 
10 Beep tone - CMOS register read/write error 
11 Beep tone - Cache memory error Continuous Beep tone - Memory or Video memory failures