LED flickers, then 1 flash, pause, then 6 more flashes. But then the sequence starts all over again but without the flicker. So it's like:

LED flickers, then 1 flash, pause, then 6 more flashes, then

1 flash, pause, then 6 more flashes, then

1 flash, pause, then 6 more flashes, then

1 flash, pause, then 6 more flashes, then

...etc.....

I took the MPU out and on the bench I get the 6 flashes. Then I temporarily short top of R17 and top of R23 and get the 7th flash, then the sequence starts over again.

I have replaced U7 through U11 with new. Any troubleshooting suggestions?