What Is a Test Point

A test point on the Huawei Nova 5T YAL-L21 is a designated exposed copper pad on the printed circuit board that grants low-level hardware access to the device's storage and boot subsystem. By making contact with these pads — either by shorting two points together or connecting them to a box interface — technicians can bypass the normal boot sequence and communicate directly with the UFS storage or the Kirin 980 SoC. This is essential when standard software-based recovery methods are unavailable or when the bootloader is locked and conventional flashing is blocked.

When to Use Test Points

Test points on the Nova 5T YAL-L21 become necessary in several critical repair scenarios:

  • FRP (Factory Reset Protection) bypass: When a device is locked to a Google account after a hard reset and standard methods fail.
  • Dead boot repair: When the device shows no signs of life — no display, no charging indication — due to corrupted firmware or a failed OTA update.
  • Firmware flashing: When the bootloader is inaccessible and the phone cannot enter fastboot or recovery mode normally.
  • IMEI repair: In conjunction with supported tools, test points allow engineers to restore corrupted baseband data.
  • Pattern or PIN lock removal: When the device is completely locked and ADB access is not available.

Locating the Test Point

To access the test points on the Huawei Nova 5T YAL-L21, the rear panel and battery must first be removed. The main PCB is located beneath the midframe. The ISP (In-System Programming) test pads for UFS access are found on the back side of the motherboard, typically near the UFS storage chip. These pads correspond to the UFS interface signals: CLK, CMD, DAT0, VCC, VCCQ, and GND. Exact pad coordinates vary between PCB revisions; technicians should use a high-resolution PCB diagram specific to the YAL-L21 board revision before proceeding.

Step-by-Step Access Procedure

Follow these steps carefully to use the Nova 5T YAL-L21 test points:

  • Step 1: Power off the device completely and remove the SIM tray.
  • Step 2: Apply heat to the rear glass panel and carefully pry it off. Disconnect the battery flex cable.
  • Step 3: Remove all screws securing the motherboard and lift it free of the chassis.
  • Step 4: Flip the motherboard over and identify the UFS ISP test pads using a verified PCB schematic for the YAL-L21.
  • Step 5: Connect your ISP-capable tool (e.g., EasyJTAG Plus or UFi Box) to the appropriate pads using fine-tip probes or soldered wires.
  • Step 6: Power the board via the tool's supply rail, launch the software, and select the Huawei Nova 5T or Kirin 980 profile.
  • Step 7: Execute your desired operation — FRP erase, firmware read/write, or dead boot repair.

Safety Tips and Precautions

Working with test points carries real risk of permanent board damage if not approached carefully:

  • Always disconnect the battery before probing to avoid short-circuit damage to power rails.
  • Use a regulated bench power supply if powering the board externally; do not exceed 3.8 V on the battery rail.
  • Confirm pad identity with a multimeter in continuity mode before applying any signal.
  • Avoid excessive heat when soldering to test pads — UFS chips and nearby passives are heat-sensitive.
  • Work in an ESD-safe environment using a grounded wrist strap and anti-static mat.
  • Use only software versions that officially support the Kirin 980 platform to avoid flashing incorrect firmware images.

Pin / Test Point Reference

PinDescription
CLKUFS clock signal pad on rear of motherboard — Exact pad location requires verified YAL-L21 schematic
CMDUFS command signal pad — Exact pad location requires verified YAL-L21 schematic
DAT0UFS data line 0 pad — Exact pad location requires verified YAL-L21 schematic
VCCMain UFS storage supply voltage pad (typically 2.9 V–3.0 V) — Verify voltage before connecting tool
VCCQUFS I/O supply voltage pad (typically 1.8 V) — Do not apply 3.3 V — may damage UFS controller
GNDGround reference pad — Confirm with multimeter continuity to chassis ground

Tools required: EasyJTAG Plus, UFi Box, RIFF Box 2, Medusa Pro II, Fine-tip ISP probe wires or 30 AWG wire, Heat gun or iOpener (rear glass removal), Precision screwdriver set (Pentalobe, Phillips), Regulated bench power supply, ESD wrist strap and mat, Multimeter

Supported operations: FRP Erase, Dead Boot Repair, Read Firmware, Write Firmware, IMEI Repair, Pattern/PIN Lock Removal, UFS Backup

⚠ Safety note: Do not exceed 3.8 V on battery rail. Confirm all pad identities before connection. Work ESD-safe. Incorrect ISP wiring may permanently damage UFS storage or Kirin 980 SoC.