problems with download circuit!

[kittygobeep]

download circuit problems!- even though test voltages measure correctly

I have a download circuit on a breadboard which I have been using successfully for almost a year. A couple of months ago when I used it last, it was fine. Now, apparently the hardware can't be found - but when I perform the test, I can measure the correct voltages between serial-in and ground. The correct COM port is definitely connected and I've checked all the download circuit connections! I'm using a PICAXE-18. Has anyone encountered this kind of thing before?? Thanks in advance for any suggestions...

 

[eclectic]

First quick suggestion.

Take it ALL apart, clean all the wires and legs, then rebuild it,
using different sockets on the breadboard.

e

 

[kittygobeep]

thanks, i'll try that.
meanwhile, an update - my power supply is 4.5V, but when I do the test, the "high" voltage has started to read 6V.....?

 

[alband]

Check your multimeter (er... not sure what with though - be inventive).

Also It really sounds like there's something wrong at the other end of that download cable - the PC.
What has changed on the PC since it last worked; file locations, OS upgrades (there's been a few recently), different OS, virus - scan.

If your really frazzled by it, re-install or try PIC-logiator free demo (rev-ed site under "downloads").

As for the 6V; if your multimeter turns out to be fine, well... your guess is as good as mine. Maybe someone who knows in more detail what goes on the the download test could elaborate...

 

[Pekari]

Did you measure pin serial in voltage? I had a problem sometime ago and I measured this and it sow me much more than supply voltage. That voltage coming from serial cable. It give 10V.

Vink:
Try some another Picaxe and then that which you had a problem. I did that and get it work again.