load cell to AD620 op amp, circuit not working, is chip dead

[moorea21]

Hi,

I'm building a machine that will utilise a load sensor from a digital weighing scale. The load sensor has a built in wheatstone bridge, and I'm using an AD620 op amp to get the signal up to a readable level. The first circuit is for this. There is a resistor network to provide a 3V reference voltage, with a decoupling capacitor.

The gain is set by the resistor on the far left.

I've checked all the input voltages, and all component values, (and my calculation for gain) and checked the wiring (breadboard) many times.

I get no output from pin 6 with respect to 0V.

Am I daft? Is this circuit no good for this chip? Or is the chip dead? I had a feeling it's my circuit, so I built the one below, with a small gain and a fixed input voltage, and the - input held to 0V. Still no output!

Attached are the circuits (apologies for slightly non standard symbols, I'm in UK, we draw them differently here!), and some pages from data sheet.

No idea what is wrong, but someone here will spot it instantly, I'm sure!

Thanks, Richard B

[moorea21]

The other datasheet pages, thanks!