Flashed New Firmware Blank Screen

[Legohead259]

Hello!

I recently purchased a T962A with the 2021 hardware version. I began the upgrades suggested by this repo but encountered an issue. I managed to flash the newest firmware, but on reboot, the screen is blank, the fan runs, and there is no communication from the serial port. I have verified that there are no shorts and the 5V and 3V3 power rails look fine on the board.

I would appreciate any assistance!

Thank you,

[GitLang]

Sounds possible that either they have changed something vital, or that the software flashing went wrong. Did you save a copy of the original software before you changed it?. If so, I would flash the original back in and see if it still works ok. If so, thouroughly check your new code and reflash it with great care at each step. Has anybody else successfully altered the software for 2021 hardware?.

[Legohead259]

Unfortunately, I am a complete idiot and did not save a copy of the firmware. Would not help me anyways at the moment since I cannot seem to get the machine into a boot loader state. When I attempt the ISP boot loader sequence, there is no response to my synchronization query (i.e. the LPC2134 does not respond with "Synchronized" on the UART port when I send it "?").

I have not heard anything to contrary for 2021 hardware. Supposedly one guy flashed it just fine, but I can not confirm or deny that. Do I need any of the suggested mods (better themocouples, cold junction compensation, etc.) to make the updated firmware work?

[Legohead259]

So this is very very interesting. I reassembled the case to put the project away for a couple of days and just for kicks, I turned the unit on. Sure enough, it booted exactly as expected and works. It may be the 2021 versions have a case sensor to detect if the case is fully closed or not. I will look into this over the coming days.

[GitLang]

That's possible, but you would expect a warning message on a programmed screen, rather than failing to boot.

As for improvements, there's a lot of info here, especially in the earlier days. There are some essential mods, first being sure all parts of the case have a protective earth, scraping paint off each joining area. You should also look at replacing insulation and the heat reflective golden coloured polyimide tape.

Of all the functional improvements, I think the best is the small board which adds interface for four thermocouples, with accurate linearisation, interfaced through spi/i2c. It also has a one wire temperature sensor which gets used to speed control the tiny fan in the side of the case to cool the electroncis. Don't know if the A model has that or not.

[Legohead259]

Could it be the front panel buttons malfunctioning? Specifically the F1 button being weird and forcing it to the bootloader intermittently? Does the F1 pin need to be pulled up? I've checked all power rails and everything seems to be working fine

…

On Mon, Mar 21, 2022, 12:04 Braidan Duffy ***@***.***> wrote: Thanks for the information. It's being finicky. It's not consistently booting at all. Sometimes it'll work. Then sometimes it just won't. On Mon, Mar 21, 2022, 11:04 Optician ***@***.***> wrote: > That's possible, but you would expect a warning message on a programmed > screen, rather than failing to boot. > > As for improvements, there's a lot of info here, especially in the > earlier days. There are some essential mods, first being sure all parts of > the case have a protective earth, scraping paint off each joining area. You > should also look at replacing insulation and the heat reflective golden > coloured polyimide tape. > > Of all the functional improvements, I think the best is the small board > which adds interface for four thermocouples, with accurate linearisation, > interfaced through spi/i2c. It also has a one wire temperature sensor which > gets used to speed control the tiny fan in the side of the case to cool the > electroncis. Don't know if the A model has that or not. > > — > Reply to this email directly, view it on GitHub > <#227 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/AB5UA4TWRHG524J6HR6FC53VBCFXZANCNFSM5RF6NV5A> > . > You are receiving this because you authored the thread.Message ID: > ***@***.***> >

[xnk]

Hmm, that’s odd indeed! Do you have any images of this board?As far as we’ve seen no major changes has been made to the layout for years (up until the T962A+ at least). The fact that it won’t boot the firmware and won’t enter ISP mode seems very strange.

…

On 21 Mar 2022, at 17:17, Braidan ***@***.***> wrote: Could it be the front panel buttons malfunctioning? Specifically the F1 button being weird and forcing it to the bootloader intermittently? Does the F1 pin need to be pulled up? I've checked all power rails and everything seems to be working fine On Mon, Mar 21, 2022, 12:04 Braidan Duffy ***@***.***> wrote: > Thanks for the information. > > It's being finicky. It's not consistently booting at all. Sometimes it'll > work. Then sometimes it just won't. > > On Mon, Mar 21, 2022, 11:04 Optician ***@***.***> wrote: > >> That's possible, but you would expect a warning message on a programmed >> screen, rather than failing to boot. >> >> As for improvements, there's a lot of info here, especially in the >> earlier days. There are some essential mods, first being sure all parts of >> the case have a protective earth, scraping paint off each joining area. You >> should also look at replacing insulation and the heat reflective golden >> coloured polyimide tape. >> >> Of all the functional improvements, I think the best is the small board >> which adds interface for four thermocouples, with accurate linearisation, >> interfaced through spi/i2c. It also has a one wire temperature sensor which >> gets used to speed control the tiny fan in the side of the case to cool the >> electroncis. Don't know if the A model has that or not. >> >> — >> Reply to this email directly, view it on GitHub >> <#227 (comment)>, >> or unsubscribe >> <https://github.com/notifications/unsubscribe-auth/AB5UA4TWRHG524J6HR6FC53VBCFXZANCNFSM5RF6NV5A> >> . >> You are receiving this because you authored the thread.Message ID: >> ***@***.***> >> > — Reply to this email directly, view it on GitHub <#227 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAYSRDZKXEDKLRNUS5MYWDLVBCOIDANCNFSM5RF6NV5A>. You are receiving this because you are subscribed to this thread.

[Legohead259]

Indeed. I didn't notice any hardware revisions when looking through the guide/previous posts. I will update this when I get back to my lab with pictures. Interestingly, I know how to get the oven to boot now. I can just toggle the power switch off/on rapidly and sometimes the machine will turn on normally. It operates as intended as far as I can tell. Is there an inductive/capacitive load somewhere that the controller needs in order to boot properly?

[Legohead259]

[rattboi]

I have this same hardware revision, and am experiencing the same issues. It was working quite fine for a while, but on occasion, it would not start up and get a blank LCD. I would leave it and try again in a bit, and it would work again.

I've now made some other mods and upon reassembly, it no longer wants to boot to normal mode. However, I can always hold F1 and get it into bootloader mode, so I know some code is running from the new firmware.

When it tries to boot into normal mode, the LCD flickers on for a second, then the backlight goes off. The fan and lamp lights also stay on for what I would say is 0.25 seconds before turning off.

It's quite strange, because on occasion it does turn on as expected, but for the most part I cannot get it to boot normally.

Bootloader mode is obvious because the LCD backlight stays on

[danielzinner]

I had a similar issue. Removing the Temperature sensor fixed my issue. I then added it back but supplying it 3.3V via a 100ohm resistor and a 10uF capacitor to the VDD pin directly instead of the parasitic power. The 100 ohm resistor and 10uF capacitor act as a RC- Filter on start up. It seems the MCU doesn't like GPIO.07 being pulled High when it is booting for some reason. This fixed my issue...

[danielzinner]

on another note, it seems these boards are really badly soldered. It might be worthwhile inspecting all the solder joints and re soldering any suspicious joints.

[rattboi]

I figured out the root cause of what was happening in my case, by bisecting the firmware and adding back initialization pieces one at a time. It turned out that in my attempt to add a pin for Vcc for programming, I broke one of the i2c resistors and so there was no communication to the EEPROM. No EEPROM -> blank screen. It gets stuck in an initialization step in a while loop.

Fixing the pull-up resistor got everything working again, and I flashed back the newest firmware and things are working as intended again.

[Maurizio66blu]

I had a similar issue. Removing the Temperature sensor fixed my issue. I then added it back but supplying it 3.3V via a 100ohm resistor and a 10uF capacitor to the VDD pin directly instead of the parasitic power. The 100 ohm resistor and 10uF capacitor act as a RC- Filter on start up. It seems the MCU doesn't like GPIO.07 being pulled High when it is booting for some reason. This fixed my issue...

Hi Daniel Zinner!
The pull-up resistor that you have used on GPIO.07 which value has it?
5Kohm is the right value.

[danielzinner]

Yeah 5k

…

On Wed, 14 Sept 2022 at 16:26, Maurizio66blu ***@***.***> wrote: I had a similar issue. Removing the Temperature sensor fixed my issue. I then added it back but supplying it 3.3V via a 100ohm resistor and a 10uF capacitor to the VDD pin directly instead of the parasitic power. The 100 ohm resistor and 10uF capacitor act as a RC- Filter on start up. It seems the MCU doesn't like GPIO.07 being pulled High when it is booting for some reason. This fixed my issue... Hi Daniel Zinner! The pull-up resistor that you have used which value has it? 5Kohm is the right value. — Reply to this email directly, view it on GitHub <#227 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ALBT67MBEVRGL3NAZTUASJ3V6HN7ZANCNFSM5RF6NV5A> . You are receiving this because you commented.Message ID: ***@***.***>

--

[Legohead259]

Thanks for the information. It's being finicky. It's not consistently booting at all. Sometimes it'll work. Then sometimes it just won't.

…

On Mon, Mar 21, 2022, 11:04 Optician ***@***.***> wrote: That's possible, but you would expect a warning message on a programmed screen, rather than failing to boot. As for improvements, there's a lot of info here, especially in the earlier days. There are some essential mods, first being sure all parts of the case have a protective earth, scraping paint off each joining area. You should also look at replacing insulation and the heat reflective golden coloured polyimide tape. Of all the functional improvements, I think the best is the small board which adds interface for four thermocouples, with accurate linearisation, interfaced through spi/i2c. It also has a one wire temperature sensor which gets used to speed control the tiny fan in the side of the case to cool the electroncis. Don't know if the A model has that or not. — Reply to this email directly, view it on GitHub <#227 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB5UA4TWRHG524J6HR6FC53VBCFXZANCNFSM5RF6NV5A> . You are receiving this because you authored the thread.Message ID: ***@***.***>