Spectra VHF Control Head Problem D43KXA7JA7BK

hvfcadmin · Post by **hvfcadmin** » Tue May 08, 2007 6:34 am

Hopefully someone can help with this issue.

The 8 character display on one of the spectra’s in our dept has gone out for some reason.
The buttons still work, just no display. Model number D43KXA7JA7BK, Dash mount VHF with A7 Control Head (HLN6283A). Interconnect board (HLN6401A). I don’t have the time rite now to look into why the display went out, probably bad caps. We have an old UHF Spectra Model D44ZXA5JC7AK Securenet dash mount with A7 Control head (HLN6283A). But this unit has a different interconnect board, (HLN6268A). From what I have gathered off of the forum, this board is used in the Securenet spectra's and has a slot cut in the chassis of the unit with a header for a cable or something to plug into it.

Basically what I would like to know is can I swap out the UHF radios head and control board with the vhf radios head and control board, and will this mess up anything in the radio.

I don't have any schematics for the two interface boards so I may sit down one evening and ohm out the pins and see what the difference between the two connectors are. I'll post with what I find.

The two A7 control heads are the same Model number and PCB rev. number.

I have pictures of the interconnect boards if anyone needs to see them.

techie · Post by **techie** » Tue May 08, 2007 12:55 pm

I would swap the control heads, and keep the interconnect boards with the radios. You should be fine.

See http://www.open.org/~blenderm/spectra

hvfcadmin · Post by **hvfcadmin** » Tue May 08, 2007 2:31 pm

Thanks, so far everything went well, had to change the 2 smt caps on the new display, they werent leaking but the display was a little slow on starting up, after replacing all is well, better safe than sorry.

Now for the old display, i went ahead and changed the caps because they showed signs of leaking.

The problem with this display is only segment 2 is out, does anyone have the schematics for this particular A7 head or know what traces i might be able to check, im thinking mabe either the display is bad, or due to the leaking caps, a few of the vias may need fixing.

I do fine pitch smt remork all day so the soldering part is pretty easy.

hvfcadmin · Post by **hvfcadmin** » Thu May 17, 2007 6:49 am

Finally got it up and running today, there was a trace that ran between the VFD Driver and the Display that had been eaten away by the electrolyte. After repairing this and a few that were on the verge of being eaten away, i put it all back togeather and tested it out. Works like new.

hope this may help some else that may be having the same problem.