I built the 1204 Kit and it not working, so lets figure it out
Physical all the joints seem to be good and test out fine
Checking the AT89S52
Verifying the program
I the AT89S52 in an EEPROM programmer and it reads and verifies the program that diffs out with other sources on the internet
But are the ports working?
Checking the output drivers
“2TY” (SOT-23) PNP transistor LED Drive
Simulating so I can better understand the driving circuit to further diagnose
It was a faulty AT89S52, replace and it works.
Props to this site, plenty of awesome info