How to Measure Memory Chips with a Multimeter
There are 64 data pins D0-D63 between the motherboard and memory module. To protect the memory data bit pins, each of these 64 data pins (D0 to D63) is fitted with a 10-ohm resistor for current limiting. The working principle of a dedicated tester is to repeatedly test each data bit pin of the memory chip via programming, to check for breakdown or short-circuit faults on data bit pins, as well as the clock pins and address pins of the chip.
Therefore, when testing chips with a multimeter, you may adopt the same method used by dedicated testers. Connect the red probe to ground (Pin 1), and use the black probe to measure the resistance of each series resistor. The measured resistance value corresponds to the resistance of the memory chip data bit, so you can identify which chip is defective. Under normal conditions, the resistance of every data bit should be identical. Although this method is less intuitive than using a dedicated tester, it can be used to judge whether DDR memory chips are good or faulty.
According to the user manual, the memory test areas marked 2A and 2B represent single-bank and dual-bank configurations. Eight 16-bit chips are equivalent to two banks; similarly, sixteen 8-bit chips also form two banks.
2A refers to the first bank and 2B refers to the second bank.
During measurement, the data bit pins of every chip in each bank are tested cyclically. A chip is regarded as functional if it passes 3 to 5 consecutive test cycles. Good chips show the status "PASS", while faulty chips will display the defective data bit pin.
① If the system fails to enter the test upon power-up, common causes include short-circuited chips or PCB short circuits. The troubleshooting method is to desolder the chip and mount it onto a known-good PCB to verify whether the chip itself is defective and locate the root cause.
② The memory tester does not test the SPD chip; the SPD chip is optional.
③ Testing cannot be performed if the golden fingers are burned. The chip must be desoldered and installed on a known-good PCB to check its quality.
