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Old January 5th 05, 12:58 AM
Henry Kolesnik
 
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I saw the Singapore deal but it aint worth for me. I might pay $10.00 for a
good one but no more. The 7700 isn't worth that much! If I don't have any
luck I'll take it to tnext hamfest and see if I can get my money back, or
find a junker.

--

73
Hank WD5JFR

"Mark S. Holden" wrote in message
...
Henry Kolesnik wrote:
I fired up the scope and had nice patterns on MSM5524 pins 26 thru 31
about 20 volt PP but pin 25 had about 3volts PP . Later I pulled the
chip and bent pin 25 out and plugged it back and voila, no center
segment, anytime. While the chip was out I checked the pull down
resistors and they're all about 100K ohms. Pin 25 which controls the
center segment appears to be the problem. Now what I need to know is the
the IC or could it be something else?
tnx


I presume this is a new acquisition for you.

You've mentioned the previous owner had a note on the schematic indicating
pin 25 controlled that segment.

Sounds to me like he found the problem, and decided it would be easier to
sell with a segment always on than always off.

Murphy's law says since the MSM5524 is out of production and relatively
hard to find it's the most likely problem. (besides, it's the display
driver)

Here's an auction for one I found as part of an unsuccessful search for a
data sheet:

http://search.auctions.shopping.yahoo.com/search?desc=MSM5524+&auccat=23761&st=auct&f=&apg=1 &nm=1&acc=sg&alocale=0sg&sb=desc

You may be able to find a better price.