It may just show up as brown powder, (you may have had some chloride contamination somewhere like water, dirty vessels?), just keep adding copper to the solution until no more copper reacts even with heat, any gold would be pushed out of solution.
If you have any tin you will also form gold colloids, circuit boards have solder, the tin and gold my be in the filter later as gold colloids and tin gelatin, incineration of the filters and a boiling wash in HCl, and hot water rinses, you can get the gold back, a big pain in the back side, keeping tin out of nitric to begin with is really the key.
I would choose acid peroxide to remove copper and foils from the boards, (removing as much solder before hand with HCl), the copper II chloride leach is much cheaper than nitric for me, and although a challenge (tin still big trouble),it seems somewhat easier to deal with in concentrated HCl solutions.
Tin as far as I am concerned is a collector of fine gold (forming colloids), so anytime I have tin and dissolved gold or gold powders, the filtered material is reprocessed for values.
Keeping tin out of solution should be the goal; it just makes things so much simpler.