WNDR3800 advice recovering from unresponsive boot loader looping

Hardware Questions and Recommendations
1

old router that has served well for longer than should be expected but i am a curios person so...

i am wondering if recovery using jtag would be possibility?

corruption of flash holding the boot loader is my optimistic diagnosis. unit was not being flashed when it failed. it had been happily running openwrt/lede for years. started becoming unresponsive on wifi/ethernet and requiring a reset couple times a week. then sometimes not bring up network leds when power cycled. now just the power led. so i attached serial cable to see u-boot looping (log paste below).

interested in buying and learning to use a jtag cable. just wondering if flashing the boot loader on the device would help or has other hardware failed?

thanks!

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U-Boot 1.1.4 (May 27 2011 - 14:58:01)

DNI HW ID: 29763654 flash 16MB RAM 128MB (ar7100) U-boot dni25 V0.1
DRAM:  b8050000: 0xc0140180
128 MB
Top of RAM usable for U-Boot at: 88000000
Reserving 265k for U-Boot at: 87fbc000
Reserving 192k for malloc() at: 87f8c000
Reserving 44 Bytes for Board Info at: 87f8bfd4
Reserving 36 Bytes for Global Data at: 87f8bfb0
Reserving 128k for boot params() at: 87f6bfb0
Stack Pointer at: 87f6bf98
Now running in RAM - U-Boot at: 87fbc000
id read 0x100000ff
flash size 16MB, sector count = 256
Flash: 16 MB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   ag7100_enet_initialize...
þþ

U-Boot 1.1.4 (May 27 2011 - 14:58:01)

DNI HW ID: 29763654 flash 16MB RAM 128MB (ar7100) U-boot dni25 V0.1
DRAM:  b8050000: 0xc0140180
128 MB
Top of RAM usable for U-Boot at: 88000000
Reserving 265k for U-Boot at: 87fbc000
Reserving 192k for malloc() at: 87f8c000
Reserving 44 Bytes for Board Info at: 87f8bfd4
Reserving 36 Bytes for Global Data at: 87f8bfb0
Reserving 128k for boot params() at: 87f6bfb0
Stack Pointer at: 87f6bf98
Now running in RAM - U-Boot at: 87fbc000
id read 0x100000ff
flash size 16MB, sector count = 256
Flash: 16 MB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   ag7100_enet_initialize...
þþ

U-Boot 1.1.4 (May 27 2011 - 14:58:01)

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2

Needing to reboot frequently makes it unlikely to be related to bootloader.

If ethernet was wonky and network LEDs dark, I would suspect a failing switch chip or something like that.

Wndr3800 is a decade old, so it might be the time to retire it.

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3

This could be crashing due to a bad power adapter. Try a different one if you haven't already. If it's not that it's a serious hardware failure, seems unlikely it is the flash chip.

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4

thanks for reply! exactly what i needed to face reality. excellent point on the unresponsive network and the log does show initialize the switch triggering the loop.

time to dig out some old broadcom based linksys out to temporarily replace that ap.

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5

damn brilliant!! i have messed with enough single board computers that i should know to always suspect the power supply.

booted up fine with another adapter.

thanks to both of ya'll for getting me on the right track cause i was completely on the wrong path!

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