for some reason the flash gets warm(almost hot). this was not the case when i had it soldered on the pcb.
i read it again with the programmer and the contents are fine. not sure where the problem lies. checked the voltages, checked for shorts, the adapter is fine. kind of confused right now.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Sun Jul 03, 2022 17:42 Post subject:
So the device wont boot? Were you able to get a serial log of the attempt if any?
I wouldn't discount the possibility of some partition going awol or the flash chip itself, Im assuming on the current setup as shown on screenshot that it getting the correct voltages, you checked but are they right given the heat? Could be also all that cabling and sitting on the adapter causes it to run warmer.
If a partition is somehow corrupt it would account for some failed boots, but serial output would give some hints either way. If its a partition would likely be possible to get dumps from a working donor board and write them.
I realised i had the breakout board wiring wrong..
i had vcc and gnd one pin away, so gnd and vcc might have sorted. not sure if i caused damage to the board.
but now the flash doesnt get warm. vcc still reads 3.3V though.
Serial looks off atm. i will first verify that the usb uart adapter works.
unless i somehow killed the board, i think i might be close.
the-joker wrote:
So the device wont boot? Were you able to get a serial log of the attempt if any?
I wouldn't discount the possibility of some partition going awol or the flash chip itself, Im assuming on the current setup as shown on screenshot that it getting the correct voltages, you checked but are they right given the heat? Could be also all that cabling and sitting on the adapter causes it to run warmer.
If a partition is somehow corrupt it would account for some failed boots, but serial output would give some hints either way. If its a partition would likely be possible to get dumps from a working donor board and write them.
Serial logs (in all cases) a must to determine what and then try to hash the partition contents to compare to a working one, depending what serial output says.
ok so serial adapter is fine. verified with a wrt54GL.
it might be that i flash the bootloader wrong? there are pages, block etc. im not familiar with those. but the bootloader appears to be at address 0x00.. and since the flash still works..
What is wrong with the one I posted in that thread?
This is what's wrong with it. Open the file with HxD and look at it. 1024kb is twice the size of the normal bootloader on Broadcom ARM devices. Do you have this router? If so, would be helpful to see the information of cat /proc/mtd.
Hmmm you cannot really expect the router to work with soldered fly wires connected to a breadboard holding the NAND.
Breadboards have terrible capacitive effects. Even at few hundreds of kHz it starts causing trouble, which is why it cannot be used for prototypes involving high-speed signal transmission.
It may work at low speed to write/read using your programmer, but when clocked by the router board in the MHz range it is very unlikely to work. The router is probably not able to read the chip content at all.
as a matter of fact, i did expect it to work lol. i have read blog posts where people had a similar setup to dump NAND content. I might just get rid of the breadboard and use the jumper wires directly..
anyway inserting the nand in that adapter on the breadboard is a bit of pain, as you have to make sure the pins are aligned. i managed to short vcc and gnd during mounting it in there, the flash got hot but surprisingly it did not die. i can read and write to it with the programmer just fine. Even after being super careful with everything.. 3.3V on the router pcb is still ok. not sure if something else is fried. the only thing lights up are the ethernet green LEDs on the back when the unit powers up. thats how it is since i bricked it.
i opted for this fly wire setup, because i might have flashed the CFE wrong and it might need another flash and another, so all i have to do is remove it from the adapter on the breadboard.
the pcb pads where the flash goes are really sensitive. i almost ripped some of them. unfortunately my chinese UV lamp does not harden the UV mask properly and the pads are floating lol. i have to use a laser or sth.
belotv wrote:
Hmmm you cannot really expect the router to work with soldered fly wires connected to a breadboard holding the NAND.
Breadboards have terrible capacitive effects. Even at few hundreds of kHz it starts causing trouble, which is why it cannot be used for prototypes involving high-speed signal transmission.
It may work at low speed to write/read using your programmer, but when clocked by the router board in the MHz range it is very unlikely to work. The router is probably not able to read the chip content at all.
By looking at the picture, let's be honest ... you can get rid of that router. A lots of pads are damaged and it is a most probably a multilayer PCB so almost impossible to fix that.
The chip itself may work, but it is very unlikely that on the board.
CFE may have been your initial issue, but your current issue is most likely related to hardware damage.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Thu Jul 07, 2022 9:00 Post subject:
That just looks dirty to me There is a concerning area, its not a really good picture, but there seems to be some traces being bridged see my screenshot.), but I tend to agree that, when the setup was being done the vcc vs gnd may have been a contributor factor to current (pun intended) situation.
Now that the CFE is flashed and I presume following @pitfermi chat over at my discord server that the original MAC addresses have been writen to the donor CFE and flashed back, that its time to clean those pads remove the flywires and put the flash back into place.
There is a great deal of wiring atm, all this adds some resistance to the circuit where the tolerances may be just over the range.
The ripped pads are NC (no connect). the other ones are still attached.
@joker. i made sure to check for shorts/bridges.
also regarding the red area, i cut the excessive wire. it sits on the cap.
belotv wrote:
By looking at the picture, let's be honest ... you can get rid of that router. A lots of pads are damaged and it is a most probably a multilayer PCB so almost impossible to fix that.
The chip itself may work, but it is very unlikely that on the board.
CFE may have been your initial issue, but your current issue is most likely related to hardware damage.
