How to use a multimeter for the measurement of memory chips
In the motherboard and memory data pins are 64, D0-D63, in order to protect the memory data bit feet, in D0-D63 the 64 data bit feet are added a resistance value is not in the resistor (10 ohms) to play the role of current limitation. The main principle of the tester is to use the procedure to repeat the test memory chip for each data bit pin, to see if there is no breakdown or short-circuit data bit pin, there is the chip clock pin, address pin.
So use a multimeter to test the chip can also be used to test the tester's method to measure, as long as the red pen to ground (1 foot), the black pen to measure the resistance of the row of negative resistance, is the memory chip data bit resistance to determine which chip is bad, if normal, each data bit resistance value is the same. But still not as intuitive as the tester, with this method can measure the good and bad DDR memory chips.
According to the instruction manual, the measurement of memory 2A, 2B here, refers to the meaning of single and double group. However, there are 8 16-bit chips, which are also equivalent to two groups, and 16 8-bit chips, which are also equivalent to two groups.
2A is the first group and 2B is the *second* group.
Measurement will cycle through the data bit pins of each chip in each group. Generally measured 3 times -5 times not bad is good. Good chip is: PASS. bad chip will show the bad data bit pin.
1, the boot can not jump into the test, generally: chip short circuit, PCB board short circuit. The solution is to remove the chip and replace it with a good PCB board to test the chip to see what the problem is.
2, the memory tester does not test the SPD chip, SPD chip can be dispensable!
3, If the gold finger is burnt, you can't test it, you must remove the chip and replace it with a good PCB board to test the chip.
