Reset sliders to default (zero) when a PopupMenu item is selected

Question

I am setting up a UI with sliders that are enabled or disabled according to the item in a PopupMenu. I have been trying to figure out how to reset the sliders to the default value of zero when I select another item from the PopupMenu. After reading the documentation I think that Refresh should do the trick but I am missing something. It seems that after refresh the sliders need to be updated but I cannot figure out how. Can you help? Please see the mwe below. I am using v 12.1.1.0. Thank you!

BU

(* Initialization section *)
dMin = -500; dMax = 500; dStep = 0.1;
aMin = 0; aMax = 500; aStep = 0.1;

PopupMenu[Dynamic[tType], {
  {0, 0, 1, 0, 0, 0} -> "t1",
  {1, 0, 1, 1, 0, 0} -> "t2",
  {1, 0, 1, 1, 1, 1} -> "t3",
  {1, 1, 1, 1, 1, 1} -> "t4",
  {2, 1, 1, 1, 0, 0} -> "t5",
  {3, 1, 1, 1, 0, 0} -> "t6",
  {0, 1, 1, 1, 0, 0} -> "t7",
  {0, 1, 1, 1, 1, 1} -> "t8"}]

Manipulate[Grid[{
   {"a", Slider[
     Dynamic[aa], {If[tType[[1]] == 3 , 1.5 bb, dMin], 
      If[tType[[1]] == 2, 1.5 bb, If[1.5 bb <= dMax, dMax, 1.5*dMax]],
       dStep}, Enabled -> tType[[1]] > 0, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightBlue, ImageMargins -> 0]},
   {"b", Slider[Dynamic[bb], {dMin, dMax, dStep}, 
     Enabled -> tType[[2]] > 0, 
     Exclusions -> {If[tType[[2]] > 0, 0, None]}, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightBlue, ImageMargins -> 0]},(* 
   excludes zero from types 4 t0 8 *)
   {"c", Slider[Dynamic[cc], {dMin, dMax, dStep}, 
     Enabled -> tType[[3]] > 0, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightBlue, ImageMargins -> 0]},
   {"d", Slider[Dynamic[dd], {aMin, aMax, aStep}, 
     Enabled -> tType[[4]] > 0, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightBlue, ImageMargins -> 0]},
   {"e", Slider[Dynamic[ee], {dMin, dMax, dStep}, 
     Enabled -> tType[[5]] > 0, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightMagenta, ImageMargins -> 0]},
   {"f", Slider[Dynamic[ff], {aMin, aMax, aStep}, 
     Enabled -> tType[[6]] > 0, 
     Appearance -> {Small, "UpArrow", "Labeled"}, 
     Background -> LightMagenta, ImageMargins -> 0]}},
  Frame -> Outer, ItemSize -> {{1, 21}}], 
 Dynamic[tType, 
  Refresh[{aa = 0, bb = 0, cc = 0, dd = 0, ee = 0, ff = 0}, 
   TrackedSymbols :> {tType}]], AppearanceElements -> None]

Answer 1

Replace Dynamic[tType] in the first argument of PopupMenu with

Dynamic[tType, (tType = #; aa = bb = cc = dd = ee = ff = 0;) &] 

to get