An/art-13 low grid current

[iw5ci]

After the cosmetic restoration of my second art-13 , i am Now working on the electric refurbishment.
The situation is this: bf=ok, rf final amp = ok.
But i have a problem in the multiplier circuit. I have followed the instructions about peaking the grid current in every position of control a. The grid current is strong (half scale) in the first 6 segments , but when is involved the second multiplier, the grid current is definitely low (1/4) scale. I have checked the 1625 tubes and they are ok, and the tension on the caps of the second multiplier tube is 402 volts.
In this conditions, i have 100w in 80 meters, but only 40w in 40 and upper frequency ( all with 900v hv).
What do you suggest to check to solve this problem?