Looking for IC 74H103 for SB-104

[Chuck W4MIL]

In a message dated 3/15/01 18:40:07 PM Eastern Standard Time,
sdhudson at CAHNERS.COM writes:

>  find
>  that it apparently needs a new 74H103 IC on its frequency counter board. I
>  can't seem to find one. Any suggestions?


Steve,

May I be so bold as to ask what leads you to that conclusion?  Seldom do the
IC's go bad on one of these without some serious intervention that defies
normal trouble shooting techniques.  I have two (2) SB-104A's plus the
console that has the digital clock/timer/et al...........

The biggest problem with the SB-104A is plug in IC's.  I found that by
carefully removing EVERY plug in device;  cleaning its legs;  cleaning the
socket; and re-springing the legs so that a good mechanical fit would
ensue---------- solved many perceived problems.  Next was the tightening of
ALL thru chassis screws/bolts to ensure a proper ground.  Finally, clean and
re-seat each plug in board.  A good alignment is in order and if one checks
voltages, etc per the manual any remaining troubles will appear.

I have found several of the small electrolytics to be leaky.  Usually 10ufd @
50volts or similar.  Just replace them if they are a problem.

Should the displays be at fault, there are things in the works by a fellow NG
member to offer plug-n-play LED replacements for the fluorescent displays.

The 104A is pretty tough if previous owners haven't committed acts that defy
basic logic where troubleshooting is concerned.

Check voltages, resistances, etc with the manual and schematic and the
problem will soon be found.

If all this has been accomplished, then delete this note and re-order the IC.

Best 73 de W4MIL

Chuck

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