On the Bench ALL OVER the EFFING BENCH Tonight...A few days ago I got a bug up my arse to make a debugging breakout for the 54600A/54621D J900 connector; I needed to be able to get probes on with the monitor live and I needed to be able to insert a substitute BRIGHTNESS pot for the CDM-7SF191 monitor.
You know, just in case there might be a easy way to make it work. I started with a scrap of PCB I had that was already the right size, then added a bit of socket header and pin header, then on pins 7-12 I substituted pins from Dupont splice header to be able to use common Dupont female breadboarding jumpers to break out the signals for testing.
Here's the pinout (ribbon plug flipped hole-side up) and the finished breakout in place on the back of the 54600A.
First thing I wanted to look at was the full-bright vs half-bright signals on the 54600A; as expected, they are TTL.
After poking around pins 7-12 of the 54621D, I found only one that looked anything like signal. Rigol is displaying VSync & HSync of both scopes; looks like there's additional information carried on the 54621D's VSync, but otherwise the same TTL signals. Pins 7, 8, 9, & 12 I couldn't distinguish anything valid apart from ambient noise; pin 10 is connected to GND fill on mainboard.
Pin 11 has signal; it varies from 0.6-1.2V P-P. HP is showing a zoom of a single wave captured as close as I could manage to the same time as that on LeSiglent. I want to say VGA of some sort, but the porches aren't always where I expect them to be; maybe blanking the screen or writing text, I suspect?
Unfortunately for my hopes of modding the CDM-7SF191 to work in place of the missing CDM-7SX191, it appears the output from the 54621D is a single-channel analog signal with TTL sync. My first guess would be SVGA at 800 x 600. Either that, or the other pins are dead and that points to what killed this scope in the first place.
Later, I may drop the mainboard on the 54621D just to poke around, see if those pins at J900 go somewhere.
But hey... the Rigol and LeSiglent both got used in anger today. Made it pretty clear my thoughts of selling off the 1054Zed were ill-considered.mnem