IR receiver punking out on my XBR

[Findm-Keepm]

Yes, there is one in series with the data, but the 5V STBY has a 47 ohm pullup resistor in series - needed to bring the collector of the IrDa output to Vcc. When the transistor is on, this resistor drops some of the 5V, as the collector (output of the IrDa Sensor)is at 0.5V or so to ground. Works like any other Open Collector logic output.

With CMOS/MOSFET outputs, the RGs(ON) is sufficient to drop the voltage, and no pull up or pull down resistor is needed. A clue that my IrDa sensor was CMOS was the packaging - a carbon impregnated ESD safe bag.

OP/50s - can you measure the 5V STBY voltage? It can be telling - low, and it could be a leaky zener, and that could decrease the sensitivity of the IrDa sensor. With no signal (no remote command), the voltage at the IrDa should be a solid 5V, with a command signal, it should drop some.