Announcement:

Recent Model ST-4 Tracking Bug

We have received several reports from recent Model ST-4 owners of a bug that causes the ST-4 to lose the guide star immediately after the Track button is depressed.  The symptoms are:  Find and Focus seems to work OK.  Calibrate seems to work OK.  When the Track button is pressed, the ST-4 may guide for one or two cycles and then act like a big tracking error has occured, make a long relay correction and loose the guide star.

We have traced the problem to two IC's that were substituted in the last production run beginning in May/June of this year.  When these IC's are replaced the ST-4 works fine.  The affected units are serial numbers XXX1612 - XXX1690.  ST-4's with serial numbers from XXX1690 to XXX1811 should be OK with the new parts already installed.   User's can verify that the modification has been made to the CPU by noting the presence of a small white label in the upper-left corner of the CPU serial number label that reads:  CLK MOD.

If you suspect that you may have one of the affected units please contact SBIG before sending the unit in for repair.

If you are not sure if your ST-4 is one of the affected units, please give us a call and we will help you determine if you unit has the substituted parts that need replacement. 

Our sincere apologies for any inconvenience this may have caused.