The PSB pin is hardwired to Vdd, which means that if you attempt to put it into serial mode by taking PSB to ground, you short your powersupply to ground. Gah.Are you sure it is hardwired (connected directly) to Vdd and not 'pulled-up' via a resistor?
Well, if I ground PSB and I power the screen up from a USB port, the port shuts down from current overload. My fluke DVM says there's 0.2 ohms between Vcc and PSB.
And the screens I got last time work just fine. So it's a defective run... Fortunately I did not fry anything, just a few $ and some hours tracking it down.
Thanks, I'll look at those. I'm not familiar with these LCDs.