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geekhack Community => Keyboards => Topic started by: bball2 on Sun, 03 November 2019, 10:22:41
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Hey guys, I was wondering if anyone knew how to reset this pcb (no button). I was trying to program it in bootmapper but after the first try it just stopped working - none of the keys are responsive. Everytime you plug the usb cable in the caps lock key flashes, but doesn't do anything else.
I tried the usual keys to hold down while plugging the usb (fn+esc, spacebar+b, fn+r) but no luck. Anyone have any ideas?
I searched around geekhack but couldn't find anything on this specific pcb, but did see comments about shorting the pcb - how does one go about doing this? Just a pair of tweezers on a specific pad?
The pcb looks like to be "apws96", and here are a few pics:
(https://i.imgur.com/EBhTRPh.jpg)
(https://i.imgur.com/nzlU2w4.jpg)
(https://i.imgur.com/DORW5cb.jpg)
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Can you read the text on the chip at the end of the space bar? If so look up the spec sheet for that and you'll probably find some info about shorting pin D0 to either VCC or GND to get to bootloader mode - I don't see any other reason to have that one pin broken out. As to the process yes, anything conductive will work to short pads including tweezers.
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Plug the keyboard in and hold a magnet over the Atmel chip or whatever the controller is. It should go into boot mode. Worked for me with my programmable pcb replacement for my Filco.
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Can you read the text on the chip at the end of the space bar? If so look up the spec sheet for that and you'll probably find some info about shorting pin D0 to either VCC or GND to get to bootloader mode - I don't see any other reason to have that one pin broken out. As to the process yes, anything conductive will work to short pads including tweezers.
It says:
ATMEL
ATMEGA32A
AU
35460K-D
1713Y J3
I found this datasheet:
http://ww1.microchip.com/downloads/en/DeviceDoc/ATmega32A-DataSheet-Complete-DS40002072A.pdf
It says to reset:
"Reset Input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running. The minimum pulse length is given in Table 28-3 on page 289. Shorter pulses are not ensured to generate a reset."
What does this mean? Do I need to make a connection between another pad and the pin on the controller that is labelled "reset"?
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Plug the keyboard in and hold a magnet over the Atmel chip or whatever the controller is. It should go into boot mode. Worked for me with my programmable pcb replacement for my Filco.
Do you need a pretty strong magnet to get this to work? I tried using a screwdriver magnet (use to pick up loose screws) and a whiteboard magnet (holding papers to a magnetic surface) and neither got the pcb to go into boot mode.
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Ok, standard chip and reset is not D0.
Do you think the label hidden under the resistor below the APWS96 says reset? If so short that hole to GND next to it and it should go into bootloader mode so you can flash it.
Of course what you flash it with is another question - it's quite likely whatever you flashed is running but doesn't match the switch matrix so there's no output...
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Ok, standard chip and reset is not D0.
Do you think the label hidden under the resistor below the APWS96 says reset? If so short that hole to GND next to it and it should go into bootloader mode so you can flash it.
Of course what you flash it with is another question - it's quite likely whatever you flashed is running but doesn't match the switch matrix so there's no output...
You might be right, it's hard to say for sure but it could definitely say reset. I tried putting a tweezer between that pin and GND next to it and the caps lock light flashes when I do that (same thing as when I connect the usb every time). So it might be in bootloader mode.
Unfortunately bootmapper won't recognize the keyboard, get the following error every time I try to connect to it:
Error opening ps2avrGB device: The specified device was not found.
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No one ever came up with a solution in this thread, so documenting for other's future use. I ran into the same problem with mine.
Solution: Hold the "U" key and then plug in your USB cable. Apparently this is a hardware level reset. After a few seconds, my keyboard was back up and running!
Source: https://www.reddit.com/r/MechanicalKeyboards/comments/72d2is/comment/dniqasf/?utm_source=share&utm_medium=web2x&context=3
I hope I help someone else! :thumb: