H5TQ2G63GFR-RDC DDR3 Memory Chip for Whatsminer CB2 V8 Control Board

H5TQ2G63GFR-RDC 2 Gbit DDR3 SDRAM | SK Hynix Memory Chip for Whatsminer CB2 V8 Control Board

The H5TQ2G63GFR-RDC from SK Hynix is a high-performance 2 Gbit DDR3 SDRAM (128M × 16-bit organisation) designed as the main RAM on the Whatsminer CB2 V8 control board. With its large storage density and high bandwidth capabilities, this memory chip handles the data buffering and runtime structures the controller's firmware needs to manage the M20-series miners' hashboard chains — exactly the role where memory faults translate into boot failures, intermittent crashes, and chain-detection errors.

The chip is packaged in a JEDEC-standard 96-ball FBGA (x16) package, ensuring physical compatibility with the original CB2 V8 footprint. Driver strength can be selected through EMRS for board-level signal-integrity tuning, and the on-chip DLL (Delay-Locked Loop) keeps the data interface synchronised across temperature and voltage variations. Replacing a failed H5TQ2G63GFR is a standard recovery path when a CB2 V8 controller boot-loops, fails RAM self-test, or shows intermittent crashes traced to memory corruption.

Large Storage Density and Synchronous Operation for Main Memory Applications

• Fully differential clock input (CK, CK#) for clean signal integrity at high data rates.
• Differential Data Strobe (DQS, DQS#) for reliable per-byte data transfer.
• On-chip DLL for precise synchronisation across the data interface.
• DM (Data Mask) for masking data writes during partial-word updates.
• Rising-edge latching for address and control inputs.
• Programmable burst length 4/8 with nibble-order and interleaved modes.
• Average refresh cycle for commercial and industrial temperature ranges.
• JEDEC standard 96-ball FBGA (x16) package — drop-in for the original CB2 V8 footprint.
• Driver strength selection through EMRS, dynamic on-chip termination, asynchronous RESET, ZQ calibration, write leveling, and TDQS support.

Where the H5TQ2G63GFR Fits in CB2 V8 Repair

The H5TQ2G63GFR is the standard DDR3 RAM IC on the Whatsminer CB2 V8 control board used by M20 / M20S / M21 / M21S miners. When the controller refuses to boot, fails self-test on memory, or shows intermittent crashes that point to RAM corruption, replacing this chip with a fresh part restores the board. Standard BGA rework profile applies — heat carefully, clean the pads, place with correct orientation, reflow. Always pair with a thorough functional test before returning the board to production duty.

H5TQ2G63GFR-RDC Technical Specifications

FAQ — H5TQ2G63GFR DDR3 Memory

Q: What's the difference between RDC and other suffixes (RDA, ROC, etc.)?
A: The suffix encodes speed grade and operating temperature. The "-RDC" in H5TQ2G63GFR-RDC denotes a specific JEDEC speed/temp grade — confirm with the original CB2 V8 specification before substituting another suffix.

Q: Can I use any 2 Gbit DDR3 chip in this socket?
A: The 96-ball FBGA × 16 footprint is JEDEC standard, but always confirm the speed grade and timing parameters match the CB2 V8 controller's memory controller config before swapping in a non-Hynix part.

Q: What rework profile do you recommend?
A: Standard BGA reflow profile — preheat to 150°C, ramp to peak around 240-250°C, hold for 30-60 seconds, controlled cooling. Use flux paste and clean residue with isopropyl alcohol before reflow.

Q: Do I need to re-flash the controller after replacing the RAM?
A: No — the firmware lives on the controller's flash, not the DDR3 RAM. Once the RAM is replaced and tests good, the board boots normally.

Q: Bulk pricing available?
A: Yes — email contact@lys-sz.com for tray-quantity pricing.

Related products

• Whatsminer CB2 V8 H3 Control Board (M20/M21)
• Whatsminer CB4 V10 H6 Control Board
• AM29F400B-55EI 4 Mbit NOR Flash Memory
• Whatsminer H6 / H6OS BGA Reballing Stencil

Whatsminer repair benches ordering H5TQ2G63GFR DDR3 chips in volume? Email contact@lys-sz.com for bulk pricing and matched control-board kits. Worldwide shipping from our Shenzhen warehouse.