UPLOAD BOOTLOADER

[Luca66]

I'll check the components. It will take a very powerful magnifying glass. I do not hide that I do not feel comfortable working on SMD components, but I will try. One thing is for sure, the problem lies after the ch340.

[Faraaz VK4JJ]

I'll check the components. It will take a very powerful magnifying glass. I do not hide that I do not feel comfortable working on SMD components, but I will try. One thing is for sure, the problem lies after the ch340.

https://www.ebay.com.au/itm/174830517628

I bought this device (before my microscope). It is excellent. Highly suggest buying one, only 24 EUR/25USD delivered. Make your life easier.

One thing is for sure, the problem lies after the ch340.

This makes it easier then. If you are sure it is not the CH340, then check the ringed components below. Also look on the Atmega, check pins 29,30,31 (correspond to the PC6_RESET, PD0_RXD, PD1_TXD) to make sure the pins are correctly soldered to the board and none are floating.

[Luca66]

I'll check the components. It will take a very powerful magnifying glass. I do not hide that I do not feel comfortable working on SMD components, but I will try. One thing is for sure, the problem lies after the ch340.

https://www.ebay.com.au/itm/174830517628

I bought this device (before my microscope). It is excellent. Highly suggest buying one, only 24 EUR/25USD delivered. Make your life easier.

One thing is for sure, the problem lies after the ch340.

This makes it easier then. If you are sure it is not the CH340, then check the ringed components below. Also look on the Atmega, check pins 29,30,31 (correspond to the PC6_RESET, PD0_RXD, PD1_TXD) to make sure the pins are correctly soldered to the board and none are floating.

It is for this fear of mine in working on SMDs that I have chosen to take the 12 volts elsewhere, see photo.

I will do it, I check. Thanks

[CT4AJ]

Congratulations to you, Luca66.
Next week upon arriving home i will try to load firmware via ISP.
Many thanks to Faraaz, VK4JJ for the identification of possible hardware failures in usb path.
Luca, if you find something interesting let us know in this topic.
Below, just for curiosity its the printout of syslog of my linux machine:
#####
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.053529] usb 1-4: new full-speed USB device number 5 using xhci_hcd
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.181098] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.417061] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8460.653479] usb 1-4: new full-speed USB device number 6 using xhci_hcd
Apr 25 16:47:27 elnunes-N14 kernel: [ 8460.781531] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8461.017498] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8461.125462] usb usb1-port4: attempt power cycle
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.541487] usb 1-4: new full-speed USB device number 7 using xhci_hcd
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.541733] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.749546] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.957047] usb 1-4: device not accepting address 7, error -71
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.085276] usb 1-4: new full-speed USB device number 8 using xhci_hcd
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.085470] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.293230] usb 1-4: Device not responding to setup address.
Apr 25 16:47:29 elnunes-N14 kernel: [ 8462.500984] usb 1-4: device not accepting address 8, error -71
Apr 25 16:47:29 elnunes-N14 kernel: [ 8462.501105] usb usb1-port4: unable to enumerate USB device
######

[Faraaz VK4JJ]

Congratulations to you, Luca66.
Next week upon arriving home i will try to load firmware via ISP.
Many thanks to Faraaz, VK4JJ for the identification of possible hardware failures in usb path.
Luca, if you find something interesting let us know in this topic.
Below, just for curiosity its the printout of syslog of my linux machine:
#####
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.053529] usb 1-4: new full-speed USB device number 5 using xhci_hcd
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.181098] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:26 elnunes-N14 kernel: [ 8460.417061] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8460.653479] usb 1-4: new full-speed USB device number 6 using xhci_hcd
Apr 25 16:47:27 elnunes-N14 kernel: [ 8460.781531] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8461.017498] usb 1-4: device descriptor read/64, error -71
Apr 25 16:47:27 elnunes-N14 kernel: [ 8461.125462] usb usb1-port4: attempt power cycle
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.541487] usb 1-4: new full-speed USB device number 7 using xhci_hcd
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.541733] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.749546] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8461.957047] usb 1-4: device not accepting address 7, error -71
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.085276] usb 1-4: new full-speed USB device number 8 using xhci_hcd
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.085470] usb 1-4: Device not responding to setup address.
Apr 25 16:47:28 elnunes-N14 kernel: [ 8462.293230] usb 1-4: Device not responding to setup address.
Apr 25 16:47:29 elnunes-N14 kernel: [ 8462.500984] usb 1-4: device not accepting address 8, error -71
Apr 25 16:47:29 elnunes-N14 kernel: [ 8462.501105] usb usb1-port4: unable to enumerate USB device
######

Yours is more of a challenge.

Work methodically. Examine the schematic around Ch340.

1. Examine the usb port under magnification, ensure with a wiggle test each pin is checked.

2. Ensure continuity from each USB pin to the first downstream component.

3. Check each component on the input side (left side of the Ch340 on the schematic)

4. Check the Ch340 soldering, positively check each pin is soldered with a wiggle test

5. Check all components to the right of the Ch340.

6. Check for continuity from the relevant atmega pins to the Ch340.

7. If these steps don't reveal anything (unlikely) then replace the ch340

[Faraaz VK4JJ]

It is for this fear of mine in working on SMDs that I have chosen to take the 12 volts elsewhere, see photo.

Where have you tapped off the 12V to? I'm confused.

[Luca66]

It is for this fear of mine in working on SMDs that I have chosen to take the 12 volts elsewhere, see photo.

Where have you tapped off the 12V to? I'm confused.

In modifying the OLED display, instead of soldering the wire between the capacitor C6 and the input of the regulator U2, I preferred to connect the capacitor C6 to the 12 V present on the 14 pin strip terminal. You see it from the photo.

[DL3MHT]

Good that you managed to load the FW via ISP.

Just two observations for anybody reading this thread:

Pressing the "Detect" button always uses the option "-p m8".
That somehow makes sense because it should detect the CPU, so requesting a specific one via -p to detect the type would be odd. Later when you Write or Read data you should of course use and see the option for the Atmega 328P.

Common Windows knowledge (aka "Binsenweisheit"):
You might get a different COM-Port assigned whenever you use a different USB port on your PC. At least the initial snapshot shows COM10 and later in all failed attempts I see COM4.
So use whatever your Device Manager shows for the currently connected USB-Port of the day.

-Tobias

[CT4AJ]

Loaded beta firmware via ISP with USBasp without problems.
Have rechecked everything around CH340G, looking for bridges, poor soldering, open resistors value of resistors, rechecked usb socket.
All seemed ok.
Unable to verify condenser values.
Remaining to see if CH340G itself is broken or if xtal around its pins is running.
Does anyone have more clues ?

Regards

[Luca66]

Loaded beta firmware via ISP with USBasp without problems.
Have rechecked everything around CH340G, looking for bridges, poor soldering, open resistors value of resistors, rechecked usb socket.
All seemed ok.
Unable to verify condenser values.
Remaining to see if CH340G itself is broken or if xtal around its pins is running.
Does anyone have more clues ?

Regards

Perfect, so you managed to activate the little prodigy!