FAQ
TL;DR: Boot loops after a battery/USB swap? After 60 minutes on charge, it still rebooted; as one expert noted, "typical for a damaged battery." This FAQ helps Xiaomi Mi Max owners stuck on the logo triage battery, charge-board, and software fixes. [Elektroda, blahfff, post #17706407]
Why it matters: Clear triage steps save time, protect hardware, and speed up a successful recovery.
Quick Facts
- Charger-only boot is model-dependent: several Xiaomi models will not start without a battery present. [Elektroda, blahfff, post #17706407]
- Some Xiaomi units can run on a charger after repeated power-button resets. [Elektroda, c-y-r-u-s, post #17757650]
- One hour of wall charging did not break the boot loop in this Mi Max case. [Elektroda, czartek70, post #17706438]
- Two replacement batteries still boot-looped here, pointing to charging-path or software faults. [Elektroda, czartek70, post #17711711]
- If software is suspect, reflash with Fastboot or Mi Flash Pro; anti-rollback applies. [Elektroda, c-y-r-u-s, post #17757650]
Why does my Xiaomi Mi Max keep rebooting on the logo after a battery/USB swap?
That boot loop usually signals a bad or incompatible battery, or charging-path damage. "The symptoms you describe are typical for a damaged or defective battery." Reseat the battery flex and USB/charge board. Test with a known-good battery or the original board. If hardware checks pass, suspect corrupt firmware and plan a Fastboot reflash. [Elektroda, blahfff, post #17706407]
Will a Xiaomi phone power on from the charger with no battery installed?
In multiple Xiaomi models, the phone will not start on charger only. It needs a battery present to boot the PMIC. If it appears to start, it often reboots at the logo. Use a charged, known-good battery for diagnostics first. [Elektroda, blahfff, post #17706407]
How long should I charge before calling it a boot loop?
Give it a solid 60 minutes on a stable wall charger first. In this Mi Max case, an hour of charging did not stop the reboot loop. If it still cycles, investigate the battery and charging board next. Avoid moving the connector while charging. [Elektroda, czartek70, post #17706438]
I tried two new batteries and still get a boot loop — what next?
When two replacements fail, shift to software and I/O checks. Connect the phone to a PC and see if it enumerates. If detected, reflash with Fastboot or Mi Flash Pro. If the PC never sees it in any mode, suspect charge board or mainboard faults. [Elektroda, Boryc2014, post #17746096]
How do I reflash MIUI with Fastboot or Mi Flash Pro?
Use Fastboot or Mi Flash Pro to reinstall system software.
- Enter Fastboot (Power + Volume Down), then connect to a PC.
- In Mi Flash Pro, select the correct Fastboot ROM for your exact model.
- Flash and avoid anti-rollback by choosing an approved or same-version build.
"Xiaomi even blocks rollback," so match versions. [Elektroda, c-y-r-u-s, post #17757650]
Can repeated power-button presses really help a stuck Xiaomi boot?
Yes, it can kick a stuck boot sequence in rare cases. A Mi Mix 2S owner reported success after “pressing the power button several times per second.” It finally booted after a few hours of attempts. This is a workaround, not a repair. [Elektroda, jaceklac76, post #19763783]
Could the charging board or port still be the cause after replacement?
Yes. A faulty replacement board or bad solder at the charging input can cause reboots. Inspect the USB sub-board, flex, and connector seating. Replace with a known-good module to A/B test. Examine for shorts or torn pads around the port. [Elektroda, Boryc2014, post #17706505]
Should I reinstall the old USB board to diagnose the issue?
Yes. Reinstall the original USB/charging board to compare behavior. If the loop changes or stops, the new sub-board is suspect. If nothing changes, focus on the battery, wiring, or software. This A/B swap is a quick isolation step. [Elektroda, sylweksylwina, post #17706215]
How do I check battery voltage if it uses a flex connector?
Measure the battery’s open-circuit voltage to rule out deep discharge. Use thin probes to back-probe the connector safely. If you cannot measure, swap in a known-good, charged battery for comparison. Recording voltage before and after charging helps triage quickly. [Elektroda, KRY5PIN, post #17706688]
My phone boots only with the charger and shows “battery temperature too low.” What does that mean?
That can indicate a battery sensor path or board-level issue after a swap. One case booted only with a charger, warned of low battery temperature, and then looped again. Two capacitors near the battery connector were missing, and replacing them didn’t resolve it. Board diagnosis is required here. [Elektroda, blahfff, post #17759341]
Can I short the charging-line fuse to test the circuit?
Some technicians briefly bridge the charging-line fuse for diagnosis. This identifies a blown fuse or charging-path break quickly. Remove the bridge after testing and replace the fuse properly. Do not leave a short in place during regular use. [Elektroda, c-y-r-u-s, post #17757650]
Why won’t a hard reset help if the battery is dead?
A factory reset requires stable power. With a dead battery, the phone cannot stay on long enough. Charge or replace the battery first, or boot to Fastboot for service actions. Then attempt resets or flashing. [Elektroda, czartek70, post #17706105]
