Marconi 2380/2382

[Squarewave]

Hello, I have a Marconi 2380 spectrum analyser with the 2382 RF unit.

It has a fault that I think is a Data Link fault, according to the fault finding flow charts in the service manual.

So I'm wondering if anyone here is familiar with these units and if anyone has ever had this fault before?

The background:

On power up, the lights flash on sometimes either one or both units, with the debug menu being on the screen. Following the flow charts, this suggests Data Link error. Looking over the Data Link charts, it suggests probing IC11 at certain pins and if not finding 20ms interval activity, then to follow the data link through from the 2382 into 2380 which I have done.

During powerup a few days ago when I was going to make some tests, the SA burst into life and for that period of being switched on, appeared to work and function, which suggests to me that it isn't a fatal issue, perhaps poor connections somewhere? When I shut down and switched on again later on, it was back in the same fault. So I've cleaned PCB edge connectors, ribbon connectors external interlink connections and thru tested the interconnects, but the SA is still in fault.

At this stage, all I can do is suspect one of three ICs until I know more.

I wonder if anyone has any suggestions?

Thanks.