HP 28C - horizontal bars across display ?
Message #1 Posted by Kao_Tai on 1 Sept 2010, 4:54 p.m.
This afternoon my HP 28C would no longer work!
(Had worked properly ever since I bought it 23 year ago, and still did so this morning.)
When I tried to switch it on, there were only two horizontal lines on the display.
http://www.stadler-christoph.de/P1030754.jpg
And I could no longer turn it off.
I tried the self tests, and they would still work, and the display was fine during these tests.
But afterwards there still were only these bars.
I replaced the batteries for a new set (gladly our company still has them in stock).
But this didn't help.
After putting the calculator away for a few hours I tried it again.
And now it works again properly - for the time being ...
Any idea what could be the problem ?
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