How to Use a Multimeter to Test Memory Chips and Memory Cards
There are 64 data pins on the motherboard and memory, D0-D63. In order to protect the data pins of the memory, a resistor (10 ohms) with a different resistance value is added to the 64 data pins D0-D63 to limit the current. effect. The main principle of the tester is to use the program to repeatedly test each data bit pin of the memory chip to see if there are any breakdown or short-circuit data bit pins, as well as the chip's clock pin and address pin.
Therefore, when using a multimeter to test the chip, you can also use the tester method. As long as the red pen is connected to the ground (pin 1) and the black pen measures the resistance of the drain resistor, it is the resistance of the data bits of the memory chip to determine which chip is broken. , normally the resistance value of each data bit is the same. But it is still not as intuitive as a tester. This method can measure the quality of DDR memory chips.
According to the instruction manual, the measured memory is at 2A and 2B, which means single group and double group. But a 16-bit chip has 8 chips, which is equivalent to two groups, and an 8-bit chip has 16 chips, which is equivalent to two groups.
2A is the first group and 2B is the second group.
During measurement, the data pins of each chip in each group are tested cyclically. Generally, if it is tested 3-5 times and it is not broken, it is good. A good chip is: PASS. A bad chip shows bad data bit pins.
1. If the test fails to start when the computer is turned on, there are usually: chip short circuit or PCB board short circuit. The solution is to remove the chip and replace it on a good PCB board to test the quality of the chip to see what the problem is.
2. The memory tester does not test the SPD chip. The SPD chip is dispensable.
3. If the gold finger is burned, it cannot be tested. The chip must be removed and replaced on a good PCB board to test the quality of the chip.
