Repairing a Couple of Very Expensive Registered DDR5 RAM Sticks

What happened

In this case doing a reflow cycle was enough to bring the RAM back to life, with the DDR5 training now passing without issues in a test system. It’s definitely a sign of the times when repair shops get handed sticks of registered ECC DDR5 RAM by businesses to try and fix, rather than just tossing the defective ones and slotting in a fresh bunch.

This is how [northwestrepair] ended up with two of these ECC RDIMMs , with a current market valuation of a rather nice budget car. The 128 GB stick was first on the bench, with the fault being that it would fail DDR5 training on boot.

This suggests that one or more of the DRAM BGA packages had developed a cracked solder joint, which is something that you could conceivably fix with more diagnosing and testing for a single IC reballing. For the 256 GB stick things wouldn’t be so easy, as it seemed completely dead.