Rock 5T bootloop?

ROCK 5 Series 5T
1

I tried everything, only the green light is there (Original powersupply). Now i have this over Uart serial with putty:

someone any ideas??

▒@▒▒` ▒▒▒▒▒▒▒▒▒▒@▒▒▒▒▒▒▒▒G▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒DDR 9fa84341ce typ 24/09/06-09:51:11,fwver: v1.18
ch0 ttot6
ch1 ttot6
ch2 ttot6
ch3 ttot6
ch0 ttot7
LPDDR5, 2400MHz
channel[0] BW=16 Col=10 Bk=16 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
channel[1] BW=16 Col=10 Bk=16 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
channel[2] BW=16 Col=10 Bk=16 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
ch3 ttot7
channel[3] BW=16 Col=10 Bk=16 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
Manufacturer ID:0x6
ch:1 dq0 fail,write:0x1,read:0x0
ch:1 dq1 fail,write:0x2,read:0x0
ch:1 dq2 fail,write:0x4,read:0x0
ch:1 dq3 fail,write:0x8,read:0x0
ch:1 dq4 fail,write:0x10,read:0x20
ch:1 dq5 fail,write:0x20,read:0x40
ch:1 dq6 fail,write:0x40,read:0x80
ch:1 dq7 fail,write:0x80,read:0x0
ch:1 dq8 fail,write:0x100,read:0x2
ch:1 dq9 fail,write:0x200,read:0x4
ch:1 dq10 fail,write:0x400,read:0x8
ch:1 dq11 fail,write:0x800,read:0x10
ch:1 dq12 fail,write:0x1000,read:0x2000
ch:1 dq13 fail,write:0x2000,read:0x4000
ch:1 dq14 fail,write:0x4000,read:0x0
ch:1 dq15 fail,write:0x8000,read:0x0
ch:1 dq0 fail,write:0xfffffffe,read:0x0
ch:1 dq1 fail,write:0xfffffffd,read:0x400
ch:1 dq2 fail,write:0xfffffffb,read:0x0
ch:1 dq3 fail,write:0xfffffff7,read:0x1000
ch:1 dq4 fail,write:0xffffffef,read:0x75ff75df
ch:1 dq5 fail,write:0xffffffdf,read:0x75ff75bf
ch:1 dq6 fail,write:0xffffffbf,read:0x75ff757f
ch:1 dq7 fail,write:0xffffff7f,read:0x0
ch:1 dq8 fail,write:0xfffffeff,read:0x75ff75fd
ch:1 dq9 fail,write:0xfffffdff,read:0x75ff75fb
ch:1 dq10 fail,write:0xfffffbff,read:0x75ff75f7
ch:1 dq11 fail,write:0xfffff7ff,read:0x75ff75ef
ch:1 dq12 fail,write:0xffffefff,read:0x75ff55ff
ch:1 dq13 fail,write:0xffffdfff,read:0x75ff35ff
ch:1 dq14 fail,write:0xffffbfff,read:0x75ff75ff
ch:1 dq15 fail,write:0xffff7fff,read:0x0
ch:2 dq0 fail,write:0x1,read:0x0
ch:2 dq1 fail,write:0x2,read:0x0
ch:2 dq2 fail,write:0x4,read:0x0
ch:2 dq3 fail,write:0x8,read:0x0
ch:2 dq4 fail,write:0x10,read:0x20
ch:2 dq5 fail,write:0x20,read:0x40
ch:2 dq6 fail,write:0x40,read:0x80
ch:2 dq7 fail,write:0x80,read:0x0
ch:2 dq8 fail,write:0x100,read:0x2
ch:2 dq9 fail,write:0x200,read:0x4
ch:2 dq10 fail,write:0x400,read:0x8
ch:2 dq11 fail,write:0x800,read:0x10
ch:2 dq12 fail,write:0x1000,read:0x2000
ch:2 dq13 fail,write:0x2000,read:0x0
ch:2 dq14 fail,write:0x4000,read:0x8000
ch:2 dq15 fail,write:0x8000,read:0x0
ch:2 dq0 fail,write:0xfffffffe,read:0x200
ch:2 dq1 fail,write:0xfffffffd,read:0x0
ch:2 dq2 fail,write:0xfffffffb,read:0x0
ch:2 dq3 fail,write:0xfffffff7,read:0x0
ch:2 dq4 fail,write:0xffffffef,read:0xa2ffa2df
ch:2 dq5 fail,write:0xffffffdf,read:0xa2ffa2bf
ch:2 dq6 fail,write:0xffffffbf,read:0xa2ffa27f
ch:2 dq7 fail,write:0xffffff7f,read:0x0
ch:2 dq8 fail,write:0xfffffeff,read:0xa2ffa2fd
ch:2 dq9 fail,write:0xfffffdff,read:0xa2ffa2fb
ch:2 dq10 fail,write:0xfffffbff,read:0xa2ffa2f7
ch:2 dq11 fail,write:0xfffff7ff,read:0xa2ffa2ef
ch:2 dq12 fail,write:0xffffefff,read:0xa2ff82ff
ch:2 dq13 fail,write:0xffffdfff,read:0xa2ffa2ff
ch:2 dq14 fail,write:0xffffbfff,read:0xa2ff22ff
ch:2 dq15 fail,write:0xffff7fff,read:0x0
error
ERR

With RkdevTool there is fail, too.

2

The answer from KI, maybe a hardwareproblem:

What’s happening on your ROCK 5T

Your log is from the RK3588 DDR training stage, and the key issue is:

:backhand_index_pointing_right: DDR training fails on channel 1 and 2 across many DQ lines

This is very specific and unfortunately very telling:

  • The RK3588 uses LPDDR5 in multiple channels

  • Training checks signal timing + data integrity

  • Your errors show:

    • Bit flips (write != read)

    • Whole byte lanes failing

    • Multiple channels affected

Why this is almost certainly hardware

If it were software (bootloader, wrong image, etc.):

  • DDR init would still pass

  • You’d fail later (e.g. U-Boot, kernel)

Instead, you fail before RAM is usable at all, which means:

:cross_mark: Rockchip SoC cannot reliably talk to RAM
:cross_mark: Memory bus is corrupted electrically

Typical failure modes on ROCK 5T

This board is dense and fast (LPDDR5 @ 2400MHz), so it’s sensitive. The most common real-world causes:

1. BGA solder issue (most likely)

  • Micro-cracks under:

    • RAM chips

    • RK3588 SoC

  • Can happen from:

    • Heat cycles

    • Slight board flex

    • Manufacturing defect

:backhand_index_pointing_right: The fact two channels fail strongly points here.

2. RAM chip failure

  • Less common, but possible

  • Usually would affect one channel first — yours is broader

3. Power rail issue (VDDQ / VDD2)

  • If RAM voltage is unstable:

    • You get exactly these bit errors

  • Could be:

    • Bad PMIC

    • Short / damaged capacitor

What you can realistically try

These are the only meaningful tests left:

:magnifying_glass_tilted_left: 1. Mechanical test (very telling)

  • Power the board

  • While watching UART output:

    • Gently press near the RAM / SoC

If:

  • Errors change / board boots further →
    :backhand_index_pointing_right: Confirmed BGA solder issue

:thermometer: 2. Temperature test

  • Try booting:

    • Cold (after sitting off)

    • Slightly warm (after a few attempts)

If behavior changes → also points to solder cracks

:high_voltage: 3. Power sanity check

  • Use a known good, stable PSU

  • If possible:

    • Measure voltage under load

  • But since DDR init already starts fine → less likely

What will NOT help

  • :cross_mark: Reflashing with RKDevTool

  • :cross_mark: Different OS images

  • :cross_mark: SD vs eMMC boot

  • :cross_mark: MaskROM tricks

:backhand_index_pointing_right: All of these require working RAM first.

Repair options

:toolbox: Practical reality

  • RAM is soldered LPDDR5 (BGA)

  • Requires:

    • Reballing station

    • Experience with multilayer boards

Options:

  • :wrench: Professional microsoldering (expensive, not always successful)

  • :repeat_button: Replace the board (most common outcome)

Final diagnosis

:backhand_index_pointing_right: Your ROCK 5T has a hardware-level memory failure, almost certainly:

BGA solder defect under RAM or RK3588

If you want, I can:

  • Help you identify exact RAM chip location on the board

  • Tell you where to press/test safely

  • Or check if your specific batch/revision has known issues

Just send a photo of your board :+1: