Flashing mute button NAC202

Halfempty,  firstly please note that discussion of unauthorised modifications to Naim equipment, which includes 3rd party PSUs, is not permitted here - I have edited your post accordingly.  Note that Naim strongly advise against using a 3rd party PSU.  At best, performance of the pre-amp will not be as Naim intended, and at worst damage may possibly result and may invalidate any warranty.

So, as to the issue; Do you have a NAPSC connected up and powered up?  If not, do you have the paddle link fitted in place on the pre-amp?

Yes, I have a NAPSC connected and powered up

Then it sounds like the PSU may be either unsuitable or faulty.  You should refer to the manufacturer of the device, or better yet, remove it and power the NAC202 from a Naim power amp, or better, a dedicated Naim Hicap.

Are the connections correct?

That's how its connected, unless I'm missing something. It's got me stumped.

Just make sure the connections at the end of the 202 are correct and you won't get any blinking lights on the unit. 

Try connecting I one thing at a time and make sure they work as they should... starting with the napsa ..and see that the logo comes on etc ...and at what point it goes off ...or the mute starts flashing

I had a similar issue with 3rd party PSU drove me mad it was a loose wire connection inside the din plug of the non Naim din cable

Were you able to fix it on your own? Or did you get a replacement cable?

I guess the only option here is to close the thread.

Halfempty, you should contact the manufacturer or dealer who sold you the unit.  It may well be either unsuitable or faulty.