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CF IDE card checkout and final assembly problem

I had posted this to the thread dealing with ordering this card, but decided to post a new topic dealing with the problem I have had with final checkout of the board.

During assembly the board passed all the 'in progress' checks.  The final steps were to output to different ports:

I have output the following and everything passes:

QO33,80 ; Configures ports A, B and C as output ports
QO32,2B ; Selects right hand pair of digits
QO30,01; display 01on right digit pair and work through each bit - all ok

QO32,2c; Selects middle pair of digits
QO30,01; Should display 01 on middle digit pair, work through each bit - all ok

QO32,2d; Selects left hand pair of digits
QO31,01; Should display 01 on left digit pair, work through each bit - all ok

All displays are correct.

Now the final step is the Drive Select and that is where I am having trouble:

Board always comes up with 'Drive A' selected

Now,  QO34,0; no change

Reset, start again:

QO34,1; no change

I can never select drive B.   

Several generous members (thank you David Fry) have made suggestions, and here is where I now stand:

My preliminary check this afternoon shows me that there is a timing issue at U15, the 74ls02.  Using my logic analyzer and monitoring the inputs and the output (which clocks the drive select flip flop) I see a big timing difference between SEL_SECOND and WR.

What this means is that the output of the gate never goes high allowing the bit change to effect drive change/selection.

I am going to get some screen shots from the analyzer tomorrow, and if anyone has any suggestions I would greatly appreciate it.