Products > Test Equipment
Upgrading Mainboard in Lecroy DDA-3000 (aka WavePro 7300a?)
lukier:
Sorry, I just saw your post.
Good job! I did the same thing last year for my DDA-3000, mated AIMB-584 with NL10276BC20-04 display. A lot of trial and error experiments with Chrontel utilities.
Pro tip (don't ask how I know ;D ) - backup the I2C EEPROM for the Chrontel chip first before playing with the Chrontel tools :)
Converter:
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?
--- Quote ---Pro tip (don't ask how I know ;D ) - backup the I2C EEPROM for the Chrontel chip first before playing with the Chrontel tools :)
--- End quote ---
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 ;D. 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
lukier:
--- Quote from: Converter on January 19, 2021, 10:51:42 pm ---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?
Update. Now I redid the power supply to the LCD inverter entirely from the motherboard
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, but I am sure that this is enough for adjustments during use of the oscilloscope.
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?
--- End quote ---
I don't remember now. It was a year ago and now my entire lab is in boxes and will stay there for a while (moving & other reasons) so I cannot check. I think I didn't bother and just powered on the inverter from the motherboard, without any brightness control or blanking, no big deal :)
DaJMasta:
This seems to be the main WP7k thread, so I'll ask here:
I've got a WP 7300 which worked fine for a while. One day I booted it up and it had the classic wrong LEDs on the front panel (or at least, they would randomly turn off), and a relay click every acquisition. I make sure the most current board drivers were installed then went to the service menu to calibrate it, and the calibration failed without any message. I eventually narrowed it down to the hop cal failing whereas everything else is fine, though without the hop cal it seems like the whole cal doesn't save or something and it always has the relay-click-per-acquisition issue.
Other symptoms include about a division of noise on the finest timebase - if actually a real representation of a signal, it would be several GHz, beyond the normal response of the frontend. Interestingly, this noise is present not only on all channels, but with the channels ground coupled, and it's just overlaid over any injected signal.
I had a hunch that it could have been the main clock board going bad so I swapped it with a WP7200 with a same part number board, and the same symptoms persist. I've also got a bit of whine on the power supply recently, and while there is some measurable noise on the DC rails going to the ADCs, they all seem to be symmetric voltages and the noise is high enough frequency that probing on the tantalums on the bottom of the acqusition board probably wouldn't show this sort of noise.
So the challenging question is what's actually wrong with it, but I wanted to ask a different one which could help: what even is the hop cal? I understand it's LeCroy proprietary, but maybe understanding what it actually does would help me track down what part is having a bad time.
My next best guess is the timing chip in the middle of the board, but while that WP7200 maybe could be a donor (it's FPGA never fully initializes so the board doesn't respond on the control gigabit ethernet link), I'm not sure I'm equipped to remove and replace that sort of a chip.
nctnico:
I'd try reseating all the boards & connectors in the PC part of the scope first. Did you also reseat the input modules? I had a problem with my WP7200A and that was magically solved by reseating the input module. If you have a WP7200 as well then try to use the PSU from that one just to rule out it is the PSU and then swap whatever you can from the WP7200 to rule out it is that particular part.
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