Well, one I took to send to the seller. Note the missing MCX and the dodgy looking MACT button. When I upturned the board the top fell off and the contact spring vanished
The seller is telling me I could solder the socket with a normal iron "as its only 4 pins". I asked him how he would solder the 5th centre pin with an iron? hahaha. It's besides the point as it was advertised as working. Basically I've asked for a full refund or for him to send me a replacement. I've offered to return this at his cost of tracked delivery (£47), I somehow don't think he will want it back.
Nevertheless, I persisted with trying to get somewhere with it in the meantime. I found any voltage I applied to the 10A fuse (3.3V - 12V) would clamp my Rigol PSU at something around 3.3-4V. I had current limiting set to 2A but it would peak at about 1.6A. Ringing noise coming from the DC/DC converter and no indicator LEDs. The OCXO would get pretty toasty. There are various test points on board, 1.2V, 3.3V good, 5V was bad - less than 4V. A PWR test point going to the OCXO was around 8-9V even with only 5-6V supply. Another test point VREF is in the 4-5V range.
I found that not using the main power but the BT (battery?) connection on the 4 pin DBG (rx/tx) header with 5V flicked the board into life. Combining 2 supplies, 5V at BT and 6V for power in the ringing would stop when the OCXO got really hot and then would stop heating as the current dropped from 1.5A to 300mA or so. I can connect using serial OK and plenty of commands to play with. Looking at the diagnostic log this device was previously installed somewhere north of Tokyo back in 2014
When the DC/DC converter settled down I found I could remove the 5V BT supply and it would remain running. So I've been playing with the serial commands for now.