RE: Diagnostic Test Line on Star Castle??

> I was looking at the Star Castle schems (while trying to fix a board
>with a fast blinking red LED) and noticed pin 1 of U2 (74S04) labled
>"Diagnostic test line. tie low for test." I'm guessing this is for putting
>the board into SA mode so it can be used with an Exorcisor? Or is this
>something else?
 
It's tied LOW when you use the Exorcisor. The Exorcisors DIP clips
are put onto ICs N2, R2 and T2 and apply signals to pins 4, 7, 9 and 12.
The three ICs are put into tri-state mode by connecting the TEST pin to GND.
That's it's only use.

> I'm guessing the flashing LED is a watchdog reset..this board
previously
>worked but looked "Russian", now I"m getting the fast blinking LED.
> What would a solid LED indicate? Any help would be appreciated.

Yup, it's watchdog'ing on you. A solid LED indicates that the board
is constantly resetting. What has been changed on the board since the
time when it was mostly working?

Dave
---------------------------------------------------------------------------
** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in the
** message body to vectorlist-request@synthcom.com. Please direct other
** questions, comments, or problems to neil@synthcom.com.
Received on Tue Mar 19 05:34:18 2002