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eHam Forums => Elmers => Topic started by: W4AJF on November 13, 2012, 06:38:32 PM



Title: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: W4AJF on November 13, 2012, 06:38:32 PM
Hi all, I have an IC-756PRO (plain) and had to replace the EXT SP jack on the main unit. I did so but after I carefully (or so I thought) put everything back together I find that the display does not display anything. I can see it lights up but nothing is displayed. All connections look to be fine but somewhere I am missing something. I of course did a full reset but no help. The radio works except for the screen being blank. Perhaps someone knows what cable, etc would be SPECIFICALLY responsible for this symptom....

Any help?

Thanks,

Adam Farber W4AJF
Woodland Hills, CA
adamf@eeco.com


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: K7MH on November 14, 2012, 11:17:53 PM
Not much to offer here but...
If there are ribbon cables, make sure they are all well seated. Some of them may look like they are but are not.


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: AC5UP on November 15, 2012, 03:09:30 PM
When a ribbon cable plugs in to a plain header with no index notch, guide, or border around the pins it is possible to be misaligned laterally by exactly one pin and not see it. Been there, done that, the original IBM compatible disk drive cables required the color stripe on the cable line up with the arrow mark for Pin 1 on the PC board. It was entirely possible to install the cable 180 degrees 'wrong' and every PC tech knew that if the floppy drive activity light came on all the time the cable was flipped.

Most modern ribbon cable headers are indexed and 99% foolproof but you may have found the exception... Make sure the color stripe goes to Pin 1 on the header and you're not off by one pin side-to-side.


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: N4NYY on November 15, 2012, 06:39:33 PM
When I repaired my 746 backlight, one ribbon cable was not in all the way and caused the display to malfunction. A re-seating corrected that.


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: W4AJF on November 22, 2012, 03:41:25 PM
Hi, thanks for the posts. I suspected the ribbon cables may be the problem and the ones responsible that I moved are the 2 that go from the main unit board to the front panel. Even though they looked fine I installed 2 new ones but still my radio display does not show anything other then the back lighting.

Anyone else have any ideas?

Thanks again,

Adam Farber W4AJF


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: KE3WD on November 22, 2012, 05:19:08 PM
I've been stymied once or twice when a ribbon is inserted into its receptacle backwards...

Examine each receptacle to make sure that the contact side of the receptacle is actually facing the contacts on the ribbons. 


73


Title: RE: Icom IC-756PRO dispaly is blank (my fault), any help?
Post by: W4AJF on November 22, 2012, 06:56:38 PM
Nope, none of the ribbon cables were removed completely so they are all in the correct orientation. Thanks, Adam W4AJF