mits MS-18NV faults

[paul_h]

I have a mitsubishi MS-18NV split that had a completely dead indoor unit.

I replaced the PCB and everything fires up, both indicator LEDs are on straight away, the fan works.
Basically everying seems OK unit the compressor starts.
The compressor starts and runs for ~ 5sec, runs normal, 6A current draw.
After that the outdoor and indoor units cut out, the LHS LED under the word "operation" constantly flashes every second, the RHS LED under the word "indicator" goes off.
The louvre vane stays open, but the fan switches off.

If you press the man/auto button, the fan starts up again, but the LHS lED keeps flashing and the compressor doesn't try to start again.
Press the man/auto button again and the LED goes off and the louvre vane shuts as per normal.

Any ideas as a constant flash fault code isn't written on the unit?
Only shows fault for 2 or 3 flash not constant.

Edit: This is a MS-18NV, has no comms or outdoor PCB like the MSH-18NV does. The indoor powers to compressor outside, no reversing valve so no deice PCB or serial line.
That may be my problem, the wrong PCB. I asked for a MS-18NV PCB, the guy gave me the part number for a MSH and at the time I didn't know the difference so I though I had made a stuff up when writing down the model number and trusted them.

Has anyone got service manuals for the older r22 wall splits, (that also tell the different part numbers between the A1 and A2 versions for the australian models).
I have to order these parts blind over the phone, and they never understand me right or give me the right part numbers. Every single time I order something, they get it wrong.
Last mits parts I order was for the outdoor PCB and the actual indoor louvre/vane, and they sent me the louvre/vane motor and the indoor PCB.
They keep costing me money and time by not understanding what I actually want.