"**THE-RFI-EMI-GUY**" wrote in message
.. .
Subject: Intersil CA3162E/CA3161E A/D BCD/7Segment problem Weller
Soldering Station

Hi
I am trying to fil my Weller soldering station which has lost its
temperature readout. This particular model has the Intersil
CA3162E/CA3161E A/D and BCD/7Segment chips. When first turned on the
display flashes "EEE" and then goes blank. I shotgunned the repair by
replacing the filter caps in the power supply and though I had it fixed
but it is back to same problem.

In reading the Intersil application notes for the A/D convertor I don't
see a logical mode where EEE would be displayed
Does anyone have advice for troubleshooting this configuration?
--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

Double check the voltage on the secondary of your transformer. Red 24 VAC,
Blue 9 VAC and Yellow - Common. On SOME models, like the EC3000 and EC4000
series a 1 ohm resistor is placed in series with the BLUE wire usually just
inside the transformer (wrap/solder joint with wire lead).

I did have one -- where that resistor "opened" -- that caused similar
problems. The 9 VAC feeds both the +5 and -5 VDC voltages using 1N4004
diodes and 3.9 Kohm dropping resistor on negative 5 and 7805 for positive 5
VDC.

w9gb