as scientific as "likely" ....cheers 
If we are to be scientists we should perhaps quote guy who said that epoxy is not necessary to re-secure the heatsinks as the glue was there to hold them in place during shipping but I digress...just trying to give SAFE advice to someone who clearly has no idea what they are doing (OP)
SAFE advice could be just an opinion without proper scientific evidence backing it up. If we are to be scientists we should perhaps quote guy who said that epoxy is not necessary to re-secure the heatsinks as the glue was there to hold them in place during shipping but I digress...just trying to give SAFE advice to someone who clearly has no idea what they are doing (OP)
The evidence points that the voltage for some chips are not at their desired levels. It is more likely that it's a SP20 voltage configuration settings or a power supply issue.
0: DC2DC/1/:[vlt1:625 vlt2:629(DCl:794 Tl:629 Ul:688) 54W 87A 73c] ASIC:[110c (125c) 720hz(BL: 720) 91 (E:193) F:0 L:0]
1: DC2DC/1/:[vlt1:572 vlt2:576(DCl:794 Tl:576 Ul:688) 32W 56A 75c] ASIC:[ 85c (125c) 490hz(BL: 490) 76 (E:193) F:0 L:0]
LOOP[1] ON TO:0 (w:139)
2: DC2DC/1/:[vlt1:562 vlt2:565(DCl:794 Tl:565 Ul:688) 26W 47A 66c] ASIC:[ 85c (125c) 440hz(BL: 440) 58 (E:193) F:0 L:0]
3: DC2DC/1/:[vlt1:603 vlt2:608(DCl:794 Tl:608 Ul:688) 34W 57A 61c] ASIC:[ 85c (125c) 490hz(BL: 490) 81 (E:191) F:0 L:0]
LOOP[2] ON TO:0 (w:226)
4: DC2DC/1/:[vlt1:666 vlt2:672(DCl:794 Tl:672 Ul:688) 80W 119A 88c] ASIC:[120c (125c) 900hz(BL: 900) 116 (E:193) F:0 L:0]
5: DC2DC/1/:[vlt1:625 vlt2:629(DCl:794 Tl:629 Ul:688) 59W 94A 90c] ASIC:[115c (125c) 770hz(BL: 770) 110 (E:193) F:0 L:0]
LOOP[3] ON TO:0 (w:195)
6: DC2DC/1/:[vlt1:587 vlt2:592(DCl:794 Tl:592 Ul:688) 32W 55A 73c] ASIC:[100c (125c) 480hz(BL: 480) 94 (E:193) F:0 L:0]
7: DC2DC/1/:[vlt1:646 vlt2:650(DCl:794 Tl:650 Ul:688) 66W 102A 76c] ASIC:[ 85c (125c) 820hz(BL: 820) 101 (E:192) F:0 L:0]
Again here you go with your science of LIKELY which is by no means evidence lol
as you can see from his post his start volts are .67 which is much higher than the ones doing .5x hmmmm wonder why they aren't getting the proper volts...you should know that the start volts are within .005 of the setting in the gui... could there be a short somewhere
He could have also damaged the boards taking the heatsinks off...so many variables but back on topic AS5 is not really the best choice to use based on price and composition
Arctic Silver 5 3.5G tube is $10
MG Chemicals non-conductive grease which gives the same result is $15 for 150g and how many grams does it take to re-do an entire machine hmmmm....