Strobe problems

[MSL]

Hi All,

I need so help on some strobes that I cannot get to work correctly.

I built 90 strobes. After I built the strobes I programmed each one. I had a few that did not program and I found bridges that I fixed. 2 of the 90 I could not get to work.

I soldered the (three) wires (5v, ground, trigger) onto the 88 that worked. I tested each strobe after I soldered on the wires. 6 of the 88 boards do not work at all. Two others start to strobe after I apply the 5v and ground (no trigger).

I re-programmed the 6 that do not work at all and now get the following error:

“Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 00000000 Expected Value: 00000025 Received Value: 00000000
Programming failed”

I looked the boards over. I cannot see any bridges.

I do not see any bridges on any of the boards.

Any ideas would be helpful.

Mark

 

[fasteddy]

A couple of things to try.

Ensure that you do have a good solder contact on the pads, too much solder can be an issue but too little solder can also be an issue.

When programming the strobes you may not be getting a good contact through the programming holes in the baord from the picit programmer., it may help to add a extra bit of twisting pressure to ensure you are getting a good contact whilst programming.

The pic can be damaged if you applied to much heat when you soldered it in. Also if doing hand soldering of the pic this can also cause possible damage if heat is applied for too long on the legs of the pic as you can suffer from thermal stress damage. This is why i prefer the hot airgun method, less chance of suffering thermal shock damage by applying heat to only one section of a chip instead of heating the whole chip up equally.

 

[MSL]

Thanks for responding...

I checked (the best I could) all the pads. They all seem to have been soldered.

I did learn (after pulling a few hairs out) to twist the insert in the board to make contact.

I did solder these with a heat gun on an 3/16 inch aluminum plate. Some of them I did get fairly hot (burned the edges). The ones that are not working do not seem to have been over heated. With that said I could have cooked the pic. Is there any way I could test it to see if it is working (with limited test equipment)?

Mark

 

[AAH]

I haven't got any strobes to test with but that response almost sounds like the pic isn't being powered. Make sure that you have the programmer set to supply 5V. Also if you have multiple strobes wired together while attempting to program them then you may have too much load on the programmer.
As far as testing the pics almost the simplest way to test them is to hook them up to the programmer and program them. If they are fine then they should program and then run the strobe.
If you have some fine solder and a fine tipped soldering iron it might be worthwhile just touching up the joints on the pic. Even with the aid of magnification it can be hard to pick dry joint on components that small. A soldering iron and solder has the benefit of adding some flux to the mix which provides better joint wetting.

 

[fathead45]

one other issue i seemed to find while trying to program was the pins for the pickit didnt mesh well with some the strobes and they would error out. if i held them out a bit and wiggled they would finally write. but i do have some that just do not work even after swapping out nud and pic''s. so i put those on the back burner for now but i may take one that doesnt work and put all the components on a new board. if it works then i know the pcb is toast.

 

[CaptKirk]

For the couple of mine that would not program (pickit errored trying to ID the chip), I ended up doing a "reflow" with the heat gun on the PIC side and that cleared up what must have been solder bridges that I just could not see. I also would not "twist" the program cable, but I would put the header and programmer cable in the holes, then push them sideways like I was trying to get the pins to bend over and lay flat on the board (without bending too much) and that always made a good connection to program.