LE Trouble

[davel295]

I finished building my second LE earlier today and it tested OK. After dinner I plugged it back in to show my son and the digits are not lighting up. 5v & 3.3 are OK, tried going manual to test mode and that worked. Any suggestions?

Thanks in advance,

davel295

[memphislights]

check the direction of the PIC and the LED driver (big chip to the right of the 7 segment leds.)

then check all of the solder joints again.

[davel295]

check the direction of the PIC and the LED driver (big chip to the right of the 7 segment leds.)

then check all of the solder joints again.

Thanks, already ckecked orientations and even swapped chips from other board - still have problem (chips worked in other board). Gotta go to hardware/elec. store for new soldering tip b/4 resoldering.

davel295

[rrowan]

Hi Davel295

Please post pictures of both sides of the board. Double check all solder joints and make sure all parts are in the correct location and direction.

Rick R.

[davel295]

Hi Davel295

Please post pictures of both sides of the board. Double check all solder joints and make sure all parts are in the correct location and direction.

Rick R.

Thanks for the reply. Unable to post pictures. The problem has become intermittant. Everything is working except for the 7-segment digits - they don't always come on. I suspect bad solder joint. Where does their power come from so that I can make sure I check those solder joints.


davel295

[vairmoose]

the power for the chips and light is from the left power in.   if the digits are not displaying, check over the solder joints for the pic that is just to the right of the displays.  That pic is the display driver.  Ground is usually the culprit when not getting good connections...   follow the traces from the left neutral input...    touchup all the solderjoints  ...   i.e.  reflow them.   

Much easier to diagnose potential areas of difficulty when pictures are available.

Larry

[davel295]

the power for the chips and light is from the left power in.   if the digits are not displaying, check over the solder joints for the pic that is just to the right of the displays.  That pic is the display driver.  Ground is usually the culprit when not getting good connections...   follow the traces from the left neutral input...    touchup all the solderjoints  ...   i.e.  reflow them.   

Much easier to diagnose potential areas of difficulty when pictures are available.

Larry

Thanks, I'll give an update later today after I go get a new tip for soldering iron.


Davel295

[rrowan]

Hi Davel295

The other thing to double check is make sure the 7-segment LEDs are in correctly. The decimal point (ie: dot) should be closer to the bottom end of the board (where the power input) and the chip for the display is also in correctly.

Rick R.

[wbuehler]

If it has not already been suggested you might also want to check the big chip next to the segments.
This chip is the driver that controls the 3 segment displays.

Bill

[davel295]

Thanks for everyones help. All orientations were good and I switched chips with another board and still had problems, so off I went to hardware store and just got back from there with new soldering tip and checked/resoldered just about every solder joint on the board. All seems to be good for now. Must have been a cold joint.

Thanks again for being helpful (and quick about it).

davel295

[WWNF911]

Thats great news Dave!

[RJ]

Great! glad it was a simple fix.

RJ