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PCS

warning

We are actively trying to learn more about this mode, if you have any information that you think might be useful - send a message in the forum topic “PCS Mode”

It's not known what the mode is, we just discovered it by accident

What is known about this mode​

  • It's definitely not BROM / Preloader
  • MtkClient / FlashTool does not detect the phone after booting into this mode
  • If you disconnect the phone from the PC - it will continue to be in this mode
  • The phone seems to go into this mode if there is some kind of failure (like a short circuit)
  • If you boot the phone to system with USB debugging, the phone will be operated with the same VID, but the PID will still be different

WTF MIDI?​

It turns out that the device VID and PID match when MIDI mode is enabled without USB debugging.

However, MIDI is essentially a communication protocol.

Taking into account that the phone switches to this mode in case of hardware failures (e.g. short circuit) and has a special combination to activate the mode even when the phone is off.

Perhaps this protocol is used to organize communication while flashing the device in emergency mode?

Boot to PCS mode​

There are three ways to boot into PCS mode - using the VOL- button or using KPCOL testpoint

Using VOL- button​

  1. Connect the switched off phone to a PC
  2. Wait until Preloader mode is disabled and the gray battery icon appears
  3. Press and hold the VOL- button until the phone is detected by the computer

Using TestPoint KPCOL​

  1. Connect the switched off phone to a PC
  2. Wait until Preloader mode is disabled and the gray battery icon appears
  3. Short the testpoint KPCOL to GND

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Make a short circuit on the board​

warning

IT'S VERY RISKY! Use other ways, but we have to mention it

In the case of a brief short circuit involving certain non-critical components, such as capacitors, which theoretically should not cause significant damage to the device, this could be interpreted as a glitch.

As a result, the device would forcibly switch to PCS MIDI mode.

Phone Detection in PCS Mode​

On Linux and Windows, the device is detected differently in this mode

Linux​

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Windows​

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