SRF04 not working - How to verify status of 12F508?

I'm using a SRF04 sonic rangefinder. It worked for a while, and now is not.

Currently driving with a ~5 ms pulse at 10Hz, no output from transmitter. (and, obviously, no signal received by receiver or output on pinout)

Probing around on the board, the 12F508 doesn't seem to be outputting an 8 pulse 40KHz burst (output pins 2,3, according to diagram below). Is there a way I can check if the chip is functioning without a programmer?

Diagram I'm using is here: SRF04 Technical Documentation
Mine is premade, marked "SRF04." and uses the F chip instead of the C.


-Stryver

You can buy a new SRF04 for $3.00 plus $5.00 postage on eBay. I did.

Colin

Links or it didn't happen.

The schematic shows an OTP 12C508. Did you buy the module pre-made or are you DIY?

Mine is premade, and it came with the F chip instead of the C.