Weller EC2002 display goes out

[Joerg]

The Weller EC2002 is their solder station with a red 7-segment
display. Problem: After less than a minute the display goes dark
yet the temp remains stable. Seems like the chip in the station
is shot. Did anyone see this before and found a fix?

Regards, Joerg.

 

[John Woodgate]

I read in sci.electronics.design that Joerg <notthisjoergsch@removethisp

The Weller EC2002 is their solder station with a red 7-segment
display. Problem: After less than a minute the display goes dark
yet the temp remains stable. Seems like the chip in the station
is shot. Did anyone see this before and found a fix?

It could be a problem with the power supply (dried up capacitors). Can
you measure the supply voltage of the display circuit?

 

[Joerg]

John, there is a stable 5V on the display and I can't see much telltale
ripple riding on any supply. Diagnosing a lot deeper is a challenge since
the circuitry is made up of two thick film hybrids wedged against each other
back to back. Thick may be a misnomer here as one is so thin that I am
afraid I could break it with a touch. The three 7-seg devices are driven by
one of those direct bond chips under a blob of tar.

Regards, Joerg.

 

[Guy Macon]

Diagnosing a lot deeper is a challenge since
the circuitry is made up of two thick film hybrids wedged against each other
back to back. Thick may be a misnomer here as one is so thin that I am
afraid I could break it with a touch. The three 7-seg devices are driven by
one of those direct bond chips under a blob of tar.

You need to order a EC236 display board, degrees F, 120v
http://www.google.com/search?q=Weller+EC2002+ec236&lr=&filter=0

 

[Joerg]

Yes, Guy, that would be the easiest way. They want almost $100 for that little
board. Ouch.

Guess I may have to bite that bullet or dust off an old non-display station, the
ones with just a potmeter and an LED. Somehow they don't die so often which is
probably due to their simplicity.

Regards, Joerg.

 

[John Woodgate]

I read in sci.electronics.design that Joerg <notthisjoergsch@removethisp

John, there is a stable 5V on the display and I can't see much telltale
ripple riding on any supply. Diagnosing a lot deeper is a challenge since
the circuitry is made up of two thick film hybrids wedged against each other
back to back. Thick may be a misnomer here as one is so thin that I am
afraid I could break it with a touch. The three 7-seg devices are driven by
one of those direct bond chips under a blob of tar.

OK, it sounds as though even if you found the fault by some means, it
wouldn't be repairable.

 

[Guy Macon]

I read in sci.electronics.design that Joerg <notthisjoergsch@removethisp

OK, it sounds as though even if you found the fault by some means, it
wouldn't be repairable.

There is always tho old last resort before throwing it away;
reseat any connections you see and reflow any solder joints
you see. This is unlikely to help, but it only takes a couple
of minutes to try.

....Assuming that this isn't your only soldering iron... <grin>