Pulsar P4 module 401 E without light sensor

[eliasmazur]

Hi.

I have a Pulsar Executive with a P4 module (401E) and it doesn't seem to have a light sensor. The spot where I read it should be is empty, but the display lights up. It's hard to see during the day outside and it does not change brightness. Is it supposed to be that way? Or is it missing. I'll try to take a picture and post.

Thanks
Elias

[bruce wegmann]

Your sensor is missing. Some modules came with the large sensor used on the P2 and P3 circuit boards. These were evidently sensitive to heat, and could not be soldered in place, so were affixed in place using conductive silver epoxy. Over time, the epoxy loses its' adhesion to the gold pads and the sensor breaks free. I have opened P4 cases and found the sensor bouncing around inside. It's an easy fix; just scrape the old glue off the sensor, reapply new epoxy, set the sensor in place, and you're back in business. A replacement salvaged from an old P2 or P3 board will do fine.