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 Post subject: LCD Dark on Power Up ?
PostPosted: Thu Mar 10, 2016 4:14 pm 
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Joined: Tue Feb 02, 2016 12:32 pm
Posts: 7
I have completed build of HR Amp kit. It passed first three Ohmmeter tests. When I put power to it, the green power light comes on, but the LCD is blank.
-first question. Are R111 and VR1 the same component?
- when I turn VR1 clockwise the LCD is still blank

- I do have 13.5 and 4.9 at the test points on the front panel.

Btw: where do I find the serial number of my amp ?

73 Paul KC2NYU


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PostPosted: Thu Mar 10, 2016 5:54 pm 
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Joined: Mon Jul 23, 2012 6:25 am
Posts: 1142
Hi Paul,

First, your serial number is on a self-adhesive tag included with each amp that you can place on the amp. It's also written on the internal white cardboard box that has (had) the components in it.

The number one trouble with LCD is the header that goes between the LCD and the control board isn't soldered. At first only a single pin is soldered then after the boards are aligned with the front panel we go back and solder the rest. It happen occasionally that this step is missed.

If that's not the case, tell me if the backlight is lit and the display has no characters? Or is the backlight out as well. Yes it looks like you found a bug in the manual, VR1 should be R111. Can you see a row of rectangles on the upper line of the display? That's it's defoult power on condition.

73,
Jim WA2EUJ


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PostPosted: Fri Mar 11, 2016 4:33 pm 
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Joined: Tue Feb 02, 2016 12:32 pm
Posts: 7
Jim- we have brightness and text!! Feeling better. I took front panel apart and
checked pins on LCD header. At first all appeared to be soldered but on closer inspection one was poorly soldered. So I redid that one, rechecked all connections and reassembled. I also finally rediscovered the R111 contrast control.. So once all was back together and applied powered, the LCD came up blue and adjusting R111 gave me the text discribbed in the manual. So thanks for the help on this problem. I found the serial number on the box, but must have misplaced the label with the number.

73 Paul KC2NYU


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