my second raspberry has just passed away

@spllg said in my second raspberry has just passed away:

@CaLviNx as it is the 3rd rpi demised in conjunction with my duet3 6hc) while 2 other rpis (not connected to a duet board) live for years now, i feel the duet is somewhat responsible for the deaths.

Horse Manure.....

As long as the duet is not sending an over-voltage to the Rpi (and you have said yourself the Duet is not the one sending the Rpi voltage) then I dont see how it is possible for the duet to kill the Rpi.

The logic is flawed i'm afraid.

spllg

@CaLviNx what do you mean "the logic is flawed"? please explain!

edit: the rpi has been working fine fine in conjunction with the duet for more than 4 months.

spllg

@bearer no, the rpi does not boot from usb-stick but i do not know if it would have done before. the only visible difference is that the green led stays on.

i think calvinx is hinting at causation without correlation btw

anyways, no the pi4 needs an update to the boot eeprom to boot from anything other than the sd card, not sure if you can accomplish that easily without being able to boot from the sd card. maybe trying to recover the boot eeprom is worth a try, but if you say the green led does blink at boot then it sounds like it should be ok (it'd still be interesting to see if it was able to boot from another medium, however that requires changing or interfacing directly to the spi eeprom i think)

spllg

@bearer tried to follow the recovery section in https://www.raspberrypi.org/downloads/ but currently i do not have an empty sd-card. going to order one but i think unless the rpi can boot and operate from usb this will not solve my problem.

reconfigured my printer to operate without rpi - maybe this is an persistent solution although i'm going to lose some workaround.

still wondering what might be the reason for 3 dead rpis.

@spllg you could image a card that is not empty, format it, put the recovery stuff on it, and restore the original content after attempting the recovery as an alternative to ordering a new card.

the pi4 can boot from usb, but weather or not you're able to make the seemingly damaged pi's boot from usb is another matter all together, its just a long shot to determine if the issue is the sd interface or something else.

does the screen show anything when you attempt to boot the dead pi, and is there any difference with or without an sd card?

dc42

I can think of a couple of situations in which the Duet cold send over-voltage to the Pi:

If you are powering a servo for the Duet +5V supply as well as the Pi. Servos inject current into the +5V rail when they decelerate. I've seen Vcc on a Duet 2 rise temporarily to 8V when driving a servo.
If you have a static discharge to +5V, which would typically be from an un-grounded stepper motor body or from the hot end.

spllg

@bearer currently my printer has to print (estimated completition tomorrow evening - late at least half a day). after having finished i will remove the rpi and follow the recovery instructions.

the display keeps dark. maybe i can obtain information via the serial interface .. tomorrow.

spllg

@dc42

no servo but i'm thinking of installing one - how to do this in a secure way?
none of the stepper bodies is grounded. should i ground the steppers?

generally: what additional precautions should i take? what documentation did i miss?

dc42

https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Connecting_stepper_motors

@spllg said in my second raspberry has just passed away:

the display keeps dark

haven't tested how the pi4 reacts, but the previous will always display the 4 pixel interpolated rainbow thing before attempting to boot the kernel. it could be different if the boot eeprom is corrupted, but according to the internet the odds of that happening should be pretty slim.

but that you're not getting any output suggest the hdmi driver is done, or the cpu isn't even getting to the bootloader

spllg

@bearer can't get any info from the rpi - green led is unevenly blinking 3-4 times and than is switched off.

going tom buy a new rpi (€60). i will not 5v-power the duet from the rpi and see how long the rpi will be alive - hopefully longer than 4 month. if it will die again i will consider to try another board as i haven't got the time to mess around with hardware problems!

btw.: i remember the rpi freezed several times (days before) before it died.

@spllg said in my second raspberry has just passed away:

@bearer can't get any info from the rpi - green led is unevenly blinking 3-4 times and than is switched off.

going tom buy a new rpi (€60). i will not 5v-power the duet from the rpi and see how long the rpi will be alive - hopefully longer than 4 month. if it will die again i will consider to try another board as i haven't got the time to mess around with hardware problems!

btw.: i remember the rpi freezed several times (days before) before it died.

Buy an Rpi3B+ from a reputable source, use the external 5v in (with a suitable amperage PSU) to provide system power to the Duet-3 which will then push the voltage TO the Rpi (with the correct jumpers being in place on the Duet-3) that combination is 100% working on multiple Duet-3's and has been for months for me with NO issues.

if you still cant work it out I would be willing to purchase the secondhand board from you as you are obviously unable to operate it properly.

spllg

@CaLviNx i could operate the rpi using 5v-power from the duet but i would loose the ability to switch off duet's psu when the print has finished.

if you still cant work it out I would be willing to purchase the secondhand board from you

seems you are looking for a cheap board.

are obviously unable to operate it properly.

ok, it seems, i am unable to operate it correctly after i was able to do so for 4 monthts. wondering what the change could be.

i understand: i'm on my own!

i could operate the rpi using 5v-power from the duet but i would loose the ability to switch off duet's psu when the print has finished.

i think he meant use a 24v/12v for vin and a 5v for 5v_ext supply; as such you could still turn off vin

@spllg

Please correct me if i am wrong but YOU Said (and I quote)

" if it will die again i will consider to try another board as i haven't got the time to mess around with hardware problems!"

logic would dictate that you will move away from the Duet Platform it would leave a perfectly good board not being utilized as you own words (again i quote)

"i haven't got the time to mess around with hardware problems"

So my offer was to assist you in not having to suffer a total loss of the financial burden you endured to purchase the equipment.

I am luckily in a financial position to not seem like i need to be (as you say, and i quote yet again) "looking for a cheap board"

Also if you know what you are doing you can utilize the SBC to automatically control ALL the PSU's when a print has finished, Which Bearer managed to work out.

You also seem to have changed your outlook, previously you said (I quote)

" i feel the duet is somewhat responsible for the deaths"

To now saying (I quote)

"wondering what the change could be"

The Words (I quote)

"i understand: i'm on my own!"

Are factually incorrect, because the FACTS are that numerous users are trying offer you information and some are going as far as to explain things you are not able to work out on your own, so no you are not on your own.

Phaedrux

Now now, we're here to be helpful. If we're not being helpful, don't be here.

@spllg said in my second raspberry has just passed away:

@bearer can't get any info from the rpi - green led is unevenly blinking 3-4 times and than is switched off.

going tom buy a new rpi (€60). i will not 5v-power the duet from the rpi and see how long the rpi will be alive - hopefully longer than 4 month. if it will die again i will consider to try another board as i haven't got the time to mess around with hardware problems!

btw.: i remember the rpi freezed several times (days before) before it died.

i designed this a while back, but still haven't built one to test, mainly because i don't currently have a duet3

https://easyeda.com/bearer/duet36hc-isolator

back to the pi, it'd be interesting to have the boot eeprom removed or re-flashed via spi to rule out that. beyond that i think maybe turning to the pi forums to get help with a postmortem would be the way to go to get to the bottom of what is happening.

spllg

@Phaedrux you mean, i should leave - this is the only support for a €270 board.

spllg

@bearer because the rpi died while printing i do not feel it could be reactivated by reflashing the boot eeprom but i will try it laster.