The reason I'm messing around with this. One of my customers sent this to me for repair.
Symptoms: Unit would power on for a few seconds, then shut down.
There's a lot of reasons why this can happen. The power interconnect that contains a bunch of DC/DC converters has an Atmel 8 bit RISC processor that monitors all voltages including the ones on the ACQ board. It also monitors that all the fans are running.
All the DC/DC converters in the scope are powered by a 48VDC 25A 1200W Emerson power supply.
After mucking around with this scope for a few days, I finally found the culprit. There is a short on -5VDC rail somewhere on the acquisition board. A 100uF ceramic cap that is soldered on top of another cap. I removed the one next to it to get the value using my Fluke 289 DMM.
For now I've removed the cap and the scope is running. It throws errors, but this is likely due to the RF coaxial relays/attenuators being removed.
Some more pics of the solder side this time, along with the shorted cap and more gooey stuff. There's also a picture of what's left of the conductive foam. Not much... I'm not sure whether I should replace it...
Each channel of the scope is powered by its own 1.8V 40A buck power supply. Pretty impressive. Not sure what -5V powers... A/D converters, possibly.
I don't think there's anything too critical about a replacement cap, but thoughts are welcome!