Introduction

Because images are most helpful for test points, I recommend:

If you are uncomfortable opening your JMM-AL10, consider these alternatives before resorting to the test point:

Shielding & Screws:

Replace the metal shields over the connectors and tighten the screws. These are vital as they often act as the "ground" for the test point and protect the board from heat.

Once the device is in the correct mode, you will need professional service tools to execute repairs. Popular options include:

Step 1: Remove the Back Cover

Note: Some JMM-AL10 units use a MediaTek chipset. If your PC detects "MTK USB Port" when shorting, use this method.

shorting the test point forces the device’s processor into a low-level boot ROM mode.

In the context of mobile device hardware, a test point is a specific exposed copper dot, pad, or via on the smartphone’s printed circuit board (PCB). These points are originally intended for factory assembly and quality control. However, for technicians, they serve a critical function: