Screen "Flickers" When macro Starts !!

[monir]

Hello;

Sorry to bring up this old problem, but suddenly the screen flickers when I
click the button to run a relatively simple macro.
The Application.ScreenUpdating = False
does no longer have the effect of suppressing this initial jiggle!!
(I'm assuming that ScreenUpdating defaults back to True when the macro
terminates its execution.)

There're NO timers, NO event procedures, and NO other macros in this wb.

Could someone please shed some light on the possible cause ?? and how to fix
it ?

Here's the simple macro code which works fine apart from the flickering of
the screen when the macro starts.

Sub Spiral_Solver_4()
Dim myCheck As VbMsgBoxResult

'minimize the amount of flashing you see on the screen
Application.ScreenUpdating = False

' initialize values
Range("B13") = Range("B14")
Range("C13") = Range("C14")

Range("D17") = Range("A17")
Range("D18") = Range("A18")
Range("D19") = Range("E19")
Range("J16") = Range("H16")
Range("F13") = Range("F14")

SolverLoad LoadArea:="$J$20:$J$27"
SolverOptions MaxTime:=1000, Iterations:=10000, Precision:=0.0001, _
AssumeLinear:=False, StepThru:=False, Estimates:=2, Derivatives:=2, _
SearchOption:=2, IntTolerance:=5, Scaling:=False,
Convergence:=0.0001, _
AssumeNonNeg:=False
SolverOk SetCell:="$H$10", MaxMinVal:=3, ValueOf:="0", _
ByChange:="$D$17,$D$18,$D$19,$J$16"

'check if Solver failed
Test = SolverSolve(True)
MsgBox (Test) 'returns 0 or 1 for NO error

myCheck = MsgBox("0 or 1 OK." & Chr(10) & "Continue ??", vbYesNo)
If myCheck = vbNo Then
Exit Sub
End If

'continue with Solver if successful
SolverSolve Userfinish:=True
Solverfinish keepfinal = 1
Range("A1").Select

End Sub

Thank you kindly.
(Excel 2003 SP2, Windows XP)

 

[Dave Peterson]

There are some functions (in the Analysis ToolPak, IIRC) that turn on
screenupdating. Maybe your code that uses solver suffers the same problem.

I don't think there's a way you can change the behavior of these functions, but
you can turn screenupdating off as soon as it gets turned back on.

I'd add some of these debug.print statements thoughout the code:

Debug.print "step 001." & application.screenupdating

You'll be able to see what piece of code changes that setting and your code can
react to it.

 

[monir]

Dave;
Thank you and will follow your advice by inserting some debug print
statements.
In the meantime, here's some additional info which might or might not be
related to my OP:

1) I've noticed that when I open the same w/b, "calculate" appears on the
task bar although there're NO timers, NO event procedures, NO circ ref, NO
other macros, and NO links!

2) "calculate" would disappear if I enter a value in any empty cell on any
w/s, or change the text in any cell, or even press F9, etc. despite
Tools::Options::Calculation::Automatic !!

3) What does "calculate" indicate ??
Why does it show now on the task bar, though there's nothing to
calculate ??
How to identify the cell(s) that are "responsible" for this "calculate" ??

4) Could "calculate" be somehow related to the screen "flickering" ??
Probably not, since the screen still jiggles at the start of the macro even
after "calculate" disappears following 2) above!

Thank you.
(Excel 2003 SP2, Windows XP)

 

[monir]

Dave;
Debug.Print statements showed Application.ScreenUpdating as False throughout
the macro.

 

[Dave Peterson]

Calculate can appear in the statusbar when there are lots of formulas.

http://support.microsoft.com/default.aspx?scid=243495
XL: Calculate Message Remains in Status Bar If 65,536 Formula References

But I've never seen that kind of thing interfere with .screenupdating.

 

[Dave Peterson]

I don't have another guess...

Sorry.

Dave;
Debug.Print statements showed Application.ScreenUpdating as False throughout
the macro.

 

[monir]

Dave;
Here's how to eliminate such irritating problem:

1. insert at the start of the VBA macro code:
.......Application.ScreenUpdating = False
and counter it before End Sub:
.......Application.ScreenUpdating = True
2. name the w/s range of the saved optimizer model, e.g.:
.......Range("$J$20:$J$27").Name = "SolverModelArea"
3. use the range name in the SolverLoad function:
.......SolverLoad LoadArea:= SolverModelArea

Problem solved! It works fine and now the macro executes very quietly!

Regards.