Hi, Did you get the same settings as mine?
Did you connect the power control of the LCD lighting inverter in the same way?
There it is advisable to turn off the LCD glow at some moments of time during the loading of the operating system.
Since the standard LeCroy controller no longer does this for obvious reasons, I started a separate wire from the ENBKL from the connector on the motherboard.
In principle, it is worth taking from this connector all other voltages for the LCD inverter. In particular, I am interested in the LCD brightness control signal (VR signal), but I cannot see how this is controlled by the motherboard.
In the Chrontel utility chip programming menu there is an option "Enable OSD display" - I activated this item, but did not see this OSD display panel anywhere in a running system. How is LCD brightness and contrast provided here? How do I call this menu? Do you have information about this?
Pro tip (don't ask how I know ) - backup the I2C EEPROM for the Chrontel chip first before playing with the Chrontel tools
Yes, I know what you mean. At some point, I was forced to unsolder the EEPROM chip and fix the firmware using the programmer (fortunately, I had 2 AIMB-582 boards), because the only DOS utility that I had at that moment was powerless to resurrect this brick, even with trying to return the original firmware
. But later, when I got access to Chrontel CH7511B Utility and studied the theory, the modification was successful on the first attempt.
Update. Now I redid the power supply to the LCD inverter entirely from the motherboard (not just using a single contact ENBKL)
I found brightness control in the Intel video driver control menu. As I determined, this does not affect the modes of operation of the inverter. I am sure that this is enough for adjustments during use of the oscilloscope, but fluorescent lamps will always be at maximum power, which is not good for their service life.
Update. I tried to change the power of the inverter by flashing the duty cycle parameter in the range from 6.25 to 100%, but this does not change the VR control signal - there is always about 3.5V DC voltage (not PWM). Does it work differently for you?
Update. I have determined that this motherboard does not support inverter duty cycle control: the CH7511B chip pins PWM_OUT0 and PWM_OUT1 are not connected anywhere on the board. The board already has printed wire for using these pins, and even a jumper to select analog/digital brightness control, but some radio components are not installed. Thus, the VR output works in a simplified way, it is always in the same 3.45V state. I think I can fix this by modifying the motherboard.
Update. I have restored the power control function of the LCD inverter. To do this, I simply connected pin #48 of the chip CH7511 to the "VR" pin of the inverter control connector (pin #4) through a 1k resistor. I tried adding a smoothing capacitor to get analog control, but as it turned out, this is not necessary, since the original NEC 104PWBR1 inverter is digitally controlled, so that 0V corresponds to 60% power and 3.3V to 100%. Thus, I set 50% duty cycle by firmware (with a frequency of about 200 Hz), which corresponds to 80% power for this inverter, and this is optimal in my case. I use pin #1 of the CN3 connector of the inverter (see the red wire that comes from pin #3 "ENBKL" of the motherboard) to control the screen dimming at certain points in the system boot, otherwise it flashes white.
Perhaps it will be useful to someone, the datasheet for the inverter is here:
https://drive.google.com/file/d/1IJD30KvEBOUBRz3n3wEN9s3FfgjuztT2/view?usp=sharing