A customer has reported that their OBDSTAR X300 Classic G3 key programmer cannot start, and the device displays a blue screen after startup. As shown in the following picture:
If this problem occurs, we suggest trying the following solution:
Use a multimeter set to the ohms range to test the two ends of device capacitor C75. If the resistance is around 0Ω, it indicates that U17 and L8 are damaged and causing a short circuit.
Need to replace U17 and L8.
Follow the steps below to detect and repair.
Step 1: Remove the Outer Shell
Carefully remove the rubber protective case of X300 Classic G3. Then use a screwdriver to loosen and remove the fixed hex screws securing the back cover.
Step 2: Disconnect the Battery
Open the back cover. Gently press down on the battery connector clip and carefully pull out the battery connector to disconnect power.
Step 3: Test for Short Circuit
Set your multimeter to the ohms (Ω) range. Measure the resistance across both terminals of capacitor C75.
If the reading is approximately 0Ω, it indicates a short circuit.
This suggests that components U17 and L8 are likely damaged and need replacement.
Step 4: Remove Damaged Components
Use a soldering iron or a hot air rework station set to 350 ± 10°C to desolder and remove U17 and L8.
Replace L8 with a 1μH inductor of suitable size and rating.
Step 5: Verify Repair
After installing the new components, re-test capacitor C75 with the multimeter.
A correct resistance reading should be approximately 1.36kΩ, indicating the short circuit is resolved.
Step 6: Reassemble and Test
Reconnect the battery connector. Reassemble the back cover and press the power button to test the OBDSTAR G3 device.
If the device powers on normally, the repair is successful.
Step 7: Final Assembly
Secure the back cover with the screws using a screwdriver. Reinstall the rubber protective case. The replacement process is complete.
