HP Prime bricked after update

[ijabbott]

Can you get to the diagnostics screen by pressing the letters C F O and pressing the reset button?

[Claudio L.]

(06-22-2021 11:19 PM)XY0797 Wrote:  You still don't seem to understand what I mean. I mean: the calculator will work properly after firmware updates, and flash memory is good at this time, but three days after firmware updates, the new firmware failed to bypass the bad flash memory blocks and write data that caused the damage to the flash memory.
The day before the new firmware corrupted flash memory, I successfully connected to the computer using USB. At that time, I didn't know the calculator would be corrupted tomorrow. I just did a normal data backup.The new firmware then damaged the flash memory without warning during normal use.The new firmware can be connected normally by USB before, but it can not be connected after the accident, so screen problems can be excluded.

I think I understand better now. So the calculator died during normal use. The fact it was 3 days after the new firmware may or may not be related. It may or may not be the flash corruption you assume it is. It may or may not be other electrical failure on the device.
If you want to get close to the truth you have a couple of options:
a) Hook up serial cables and see console output during the OS loading sequence to see if it even starts. If there's a bad block you'll likely see an error message before it crashes. The boot loader is very verbose through the serial port, not so much on the screen unfortunately.
b) If you are able to do a), then you are likely able to attach JTAG cables and see everything even better. If it's indeed a bad flash problem, you'll be able to manually reflash.

If you are not electronically curious, then there's not much more you can do, other than accept it's bricked.

[Liamtoh Resu]

And I am looking at the problem from another angle which may or may not be relevant.

From earlier posts:

Quote: Liamtoh Resu Wrote:
Have you tried recharging the prime with one of the external 2000-10000mah batteries
that are sold for the purpose of charging smartphones?

I don't think it works because I used to use an external regulated power supply with a constant voltage of 4 volts and the calculator didn't respond.

I would check the voltage of the supply with a multimeter while the calculator is turned on.

And can the calculator do any other function while still connected to the computer?
The computer delivers five volts from the usb port.

If the calculator goes bad or stops functioning correctly after a short term, I would be looking to replace the battery. Some of us have had batteries that initially read
the correct value, but the voltage drops after putting a load on the battery.

Thanks.

[XY0797]

(06-24-2021 02:31 PM)rprosperi Wrote:  It is still difficult to understand, due to translation challenges, though we understand you are trying your best to explain.

You mention "damage to flash" many times, caused by the f/w. Why do you think it is damaged, what evidence of damage so you see, what are the precise symptoms? What exact steps do you follow and what are the results?

Without exact information, it isn't possible to narrow down the cause, so these details are needed to understand cause and possible solutions.

Also, have you tried to re-format the flash using the diagnostic menu?

Okay, let me explain my logic now.
The calculator is broken without warning and no damage process is visible. Its screen, keyboard, functions and recovery mode are normal until it is damaged.I realized it was broken when I tried to open the calculator and it didn't respond.I tried various ways to force a reboot, but it didn't work.I think it might be a problem with the screen or keyboard, and if it is, it should be able to connect to the computer after pressing the RESET key, but that doesn't work, so it's not a problem with the keyboard or the screen (the battery problem is excluded by me using the voltmeter).
I then tried to enter the recovery mode and the "factory-new" technology, but the screen was always black.
Therefore, there are only four possibilities left: ①Flash memory chip damage②CPU damage③Memory damage④Capacitance, resistance, triode, inductance and so on damage
Because three days before the accident, I upgraded the firmware for the calculator, and the only thing that the firmware can damage is the flash memory chip. Therefore, I think the flash memory chip is the most likely to be damaged, so I made a conclusion.
I tried this technique, but it didn't work. I was desperate. Verification ②③ can only replace the corresponding chip. I don't have the relevant equipment. If I buy the equipment and can't repair it, it's expensive and risky. I'm a student without a job, and I don't want to verify ②③. Because there is no circuit diagram, I can't verify ④.
Thank you very much. I'm forced to stop repairing the calculator now because I'm preparing for the exam and it will take about five days.

[XY0797]

(06-24-2021 10:49 PM)Liamtoh Resu Wrote:  And I am looking at the problem from another angle which may or may not be relevant.
From earlier posts:

Quote: Liamtoh Resu Wrote.............................

I would check the voltage of the supply with a multimeter while the calculator is turned on.
And can the calculator do any other function while still connected to the computer?
The computer delivers five volts from the usb port.
If the calculator goes bad or stops functioning correctly after a short term, I would be looking to replace the battery. Some of us have had batteries that initially read
the correct value, but the voltage drops after putting a load on the battery.
Thanks.

Thank you for your information, but the 4-volt external regulated power supply is directly connected to the battery pin. Unless the power exceeds 30 watts, it will provide a constant 4-volt voltage

[XY0797]

(06-24-2021 04:35 PM)ijabbott Wrote:  Can you get to the diagnostics screen by pressing the letters C F O and pressing the reset button?

Thank you very much, but it didn't work.
The method you provided is the same as that he provided:

(06-22-2021 03:52 PM)Albert Chan Wrote:  Instead of trying to get to recovery mode, have you considered a "factory-new" reset ?
http://hp-prime.com/files/composite_file...y_mode.pdf

[mnsk]

As my G1 Prime has suffered the same fault: Have you been able to fix the problem?

Would the method from the linked post be applicable to the G1? The NXP-Bootloader is mentioned there, but the G1 has an other processor, doesnt it?

Greetings