Redmi K30 Supreme Won’t Turn On repair

Redmi K30 supreme edition Won't Turn On, direct Repeat welding vemc_PMU main power supply, vufs12_PMU Nand MOSFET u5601 these two power supplies, fault repair. 

Redmi K30 Supreme Won’t Turn On repair

Machine model:Redmi K30 supreme Edition
Fault phenomenon: a Redmi was sent for repair by the same companymobile phone, said the normal use of no booting, press the start key 200 jump.

Redmi K30 Supreme Won't Turn On repair

Redmi K30 Supreme Won’t Turn On repair Figure 1.

The maximum reached 500 mA and then dropped to 150 mA or so.

Redmi K30 Supreme Won't Turn On repair

Redmi K30 Supreme Won’t Turn On repair Figure 2.

So the current Restart repeatedly, and the screen does not light, connect the computer directly out of 9008 mode.
Fault analysis: in general, Nand does not work. If it is used normally, we suspect that Inveracious Soldering, Nand, VCC and Nand are hung.

Repair process: rework the kit directly.

Redmi K30 Supreme Won't Turn On repair

Redmi K30 Supreme Won’t Turn On repair Figure 3.

Start to see the current, the same, even if the computer out of 9008 mode, think Nand is dead, and then look at the second maintenance idea just mentioned,Nand VCC, the new mobile phone Nand generally only has two channels of VCC.

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Redmi K30 Supreme Won’t Turn On repair Figure 4.

VEMC_PMU from main power supply, vufs12_The PMU comes from Nand MOSFET u5601.

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Redmi K30 Supreme Won’t Turn On repair Figure 5.

Direct Repeat welding to these two power supplies.

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Redmi K30 Supreme Won’t Turn On repair Figure 6.

Maintenance results: boot test, perfect repair.At this point,Redmi K30 supreme edition is in normal use, and no booting is repaired.

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Redmi K30 Supreme Won’t Turn On repair Figure 7.