It should be possible! I mean this thing runs on a single USB-PD charger right now so integrating a better and modern power supply circuit on a brand new PCB would be really kickass!
I also think everything except the flyback and the CRT connectors can be replaced with SMD resistors and probably...
I've modified `dtparam=vactive=342,vsync-invert` from 342 to 384 to have a proper 4:3 aspect ratio. After adjusting the vertical size potentiometer it seems to work well!
Also the analog board voltage hooks schematic buried in the previous thread:
WARNING: If you don't know how to deal with high voltage stuff, please stay away from this thread. I am not liable for any lethal/non-lethal injuries or damages resulting from the use of this information.
Can't believe I forgot to post it but here's my config.txt for the rpi 4 if anyone wants to replicate:
kernel=rpi4-u-boot.bin
dtoverlay=upstream-pi4
arm_boost=1
dtoverlay=vc4-kms-v3d-pi4
dtoverlay=cma,cma-256
max_framebuffers=2
arm_64bit=1
gpu_mem=16
boot_delay=0
force_eeprom_read=0...
After more than a year of service as a Raspberry Pi 4 home server, It's still going strong :) I've added a adb2usb converter courtesy of https://github.com/tmk/tmk_keyboard/tree/master/converter/adb_usb
The CRT has been continuously running ever since, it's noiseless and only consumes 30W of...
WARNING: If you dont know how to deal with high voltage stuff, please stay away from this thread. I am not liable for any injury or damages resulting from the use of this information.
With that out of the way, this is the culmination of all my mods to make the Early Classic Analog Board run...
I will list down the mods in a modified schematic of EAB later soon, hopefully folks can try it to save classic analog boards that are screwed by their broken PSU circuits :)
Yes, i retained the LM317, but i removed the 12v reg for efficiency's sake and combined all 12v rails into one, including the one on the heater, the 12v rails on the deflection IC and the softstart RC circuit in LM317's ADJ pin. I supplied the usb-pd's 20v to the input of LM317 and it seems to...
Okay, after some tweaking, it seems that the LM317 and its adjacent passives are important for limiting the current of the 31v rail. Now it's fixed, hopefully.
Finally, after the troubles i had in this thread, I'm now able to power the early Mac Classic's analog board with USB Type C!
(Right now im using its fixed up logic board that is also powered by USB Type C for demonstration purposes).
Final aim is to make it like what they did here. But with a...
Okay... Kinda feeling like an idiot now... So there's probably nothing wrong with the A/B.. I adjusted the HOT voltage, the BOMARC schematics suggested +31V but when i turned the voltage down the bad smell seems to have gone away and the horizontal width has reduced. There's still some noise but...
After some cleaning and removing some gunk, i've revived the LB with alternative power regulators, but unfortunately im still getting the same herringbone kind of pattern, the same as im getting with the Pi4, as well as the really wide output. Any ideas folks?
So yeah, when i try to display a full picture, the area around the MOSFET starts to smell quite bad... and only smells bad when i show a almost-fully white image. And it has a very bad shimmering effect as well.. not sure what to do next honestly
Also tried to adjust the width coil thingy but...