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Weller EC2002 erratic temp display on "set" mode

meemurs

Apr 13, 2011
1
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Apr 13, 2011
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Hello I just pulled out my Brand new (old) Weller EC2002 slodering iron that I bought brand new a long time ago.
I have used it about 1x in the past and it was a mess back then. I should have returned it but it is way out of warranty now. My fault.I should have returned it but that is in the past. I hate it and never attempted to fix it because I hate it. After I turn it on I am supposed to set the switch to "set" and turn the heat up to 400 degrees and tin a tip. It is doing the same as it did 8 years ago. The display displays (for example) 701,512,660,802,455, about every second it changes to a different random number. The temperture reading are generally between 400-800 degrees.
I am tempted to toss it . Has anyone seen this before and know what I should do with this ?
Thanks
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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It's out of warranty and not working. So there is probably no problem trying to fix it as you can't use it now, and making it worse is probably not going to matter :D

I would be looking for loose or broken connections to the temperature sensor first.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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So Robbert, do you have a good idea what's wrong and how to fix it?
 

davelectronic

Dec 13, 2010
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That would be the gentlemanly thing to do as they say here in the UK can you help Robbert. ? :)
 

Robbert van Herksen

Dec 12, 2011
6
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Dec 12, 2011
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Still no reply from mr 'meemurs'

Let's wait for HIS reaction first.....

My own Weller EC2002 is just falling apart (still working though!!, now 25 years old!!) so I need a replacement.

Meemers wrote in his posting (and I quote):

"I hate it and never attempted to fix it because I hate it."

He hates it and I lovvit.

So, 'sell it to me', was my original thought.

Cheers (and beers!!)

Robbert
 

davelectronic

Dec 13, 2010
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Yes good idea, if he cant be bothered with it, the old saying, one mans junk is another mans treasure, that has certainly been true for me many times over. :)
 

davelectronic

Dec 13, 2010
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If the original post date of the opening question is correct, the post was some time ago, but he might pop in again for a look about, see whats going on generally, you could leave a personal message, if the personal message notification is active in his profile setting he would get notification of a new message via email. :)
 

Robbert van Herksen

Dec 12, 2011
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If the original post date of the opening question is correct, the post was some time ago, but he might pop in again for a look about, see whats going on generally, you could leave a personal message, if the personal message notification is active in his profile setting he would get notification of a new message via email. :)

Hi there,

Thanks for the great hint, BUT:


Couldn't send a PM:

because:

------------------------------------------------------------------------------------------
To be able to send PMs your post count must be 15 or greater.

You currently have 3 posts and you can send PMs to following users only:
Resqueline, (*steve*), Ian, Becky

------------------------------------------------------------------------------------------

Arrrrrrghhhhhhh!!!

HELP ME!!!

Robbert
 

Nobody

Aug 31, 2013
12
Joined
Aug 31, 2013
Messages
12
Definite fix to Weller EC2002 erratic display and no heat.

OK humanity, here is my present to you. I hope it will save tonns of collective time tinkering with moody Wellers.

As many of you who landed on this page, I have a few of EC2002 inherited from my old job. I love these irons more than any other. Though it does not have auto-shutdown like new once, I'm attached to them, they grown into my hand and nothing can replicate that feel, that perfect temperature when solder flows soft and sticky and when flux creates light haze and amber runoff rather than blackened crust.

Unfortunately, lately, in period of about one year they all, one by one started behaving badly, reading not stable, to the point where it just refused to produced any heat.

Well, as I had a few spares I eventually accumulated a bunch with exactly same symptoms. Time has come to resolve this c#4p.

I opened them and work begun:
Please note that stations I have all with ceramic boards. I've heard about once with PCB and PicChip, like EC51, but never saw them. So this story is about the once with ceramic boards.

First thought, like with most old electronics, was to replace all electrolytics. Did that, all spanking new tantalums - noting changed.
There was plenty of posts around Interweb suggesting micro-cracks in ceramic. I don't think so. These are some of the toughest boards, probably mil-spec.

Anyway, put the one with new caps aside and got next one. This one I did not touch the caps. I went straight to cutting off ribbon, removing board and cleaning it to investigate under microscope for the cracks like described above. I found none. There was some nasty tape over three sides. I had to remove it and wash. It was very sticky. Board wash was hardly making tape glue slightly softer. I rub it off with my bare fingers and then wash board again to remove my grease. After soldering ribbon back to my surprise station was fully functional, no bad behavior or anything funky.

Yep, it got to be the glue. Got next one. To properly clean it you have to remove board. Trying to unsolder ribbon just stresses pads and melts insulation. It is my recommendation to cut ribbon off, close to the board, trim it neatly then strip it anew and solder it fresh. This way it looks clean and not abused.

As expected by now, third one now works like new.

I went back to the first one, clean it as the other two and got same result.

This is it! You don't even need any replacement parts! Isn't' it great!


TEMPERATURE SENSOR

OK, now you get bonus info: As I was tinkering with it and was getting ready to spend on spare parts I've realized that some info really missing about these stations. Temperature sensor is hard to get and very little info about technology used to measure temperature in these stations to replace them with generics.
If you have your temperature sensor open-circuit, you can make one from what you most likely have at home.
It is simple wire-type PTC. Thermal coefficient of it is slightly less than that of a copper or aluminum.I I'm guessing this is because added constant resistance of cable. Looking at metals electrical resistance thermal coefficient table it looks like many metals will work. Slight error of few degrees will not affect usability of iron. I set temperature by feel anyway.
You can wound one and pot it with high temperature silicone (hardware store, silicon for fireproofing) or other non-flammable cement like non-conductive compound.
When you trim your new sensor, at station terminals it should be 20 to 22 Ohm. It is pretty low resistance, this is why only two terminals have gold plated contacts. Other terminals are not worthy.


I hope this writing will save some of these wonderful, old stations and a lot of your time.

Cheers y'all!

:)
 

Mamo

Dec 31, 2017
3
Joined
Dec 31, 2017
Messages
3
Definite fix to Weller EC2002 erratic display and no heat.

OK humanity, here is my present to you. I hope it will save tonns of collective time tinkering with moody Wellers.

As many of you who landed on this page, I have a few of EC2002 inherited from my old job. I love these irons more than any other. Though it does not have auto-shutdown like new once, I'm attached to them, they grown into my hand and nothing can replicate that feel, that perfect temperature when solder flows soft and sticky and when flux creates light haze and amber runoff rather than blackened crust.

Unfortunately, lately, in period of about one year they all, one by one started behaving badly, reading not stable, to the point where it just refused to produced any heat.

Well, as I had a few spares I eventually accumulated a bunch with exactly same symptoms. Time has come to resolve this c#4p.

I opened them and work begun:
Please note that stations I have all with ceramic boards. I've heard about once with PCB and PicChip, like EC51, but never saw them. So this story is about the once with ceramic boards.

First thought, like with most old electronics, was to replace all electrolytics. Did that, all spanking new tantalums - noting changed.
There was plenty of posts around Interweb suggesting micro-cracks in ceramic. I don't think so. These are some of the toughest boards, probably mil-spec.

Anyway, put the one with new caps aside and got next one. This one I did not touch the caps. I went straight to cutting off ribbon, removing board and cleaning it to investigate under microscope for the cracks like described above. I found none. There was some nasty tape over three sides. I had to remove it and wash. It was very sticky. Board wash was hardly making tape glue slightly softer. I rub it off with my bare fingers and then wash board again to remove my grease. After soldering ribbon back to my surprise station was fully functional, no bad behavior or anything funky.

Yep, it got to be the glue. Got next one. To properly clean it you have to remove board. Trying to unsolder ribbon just stresses pads and melts insulation. It is my recommendation to cut ribbon off, close to the board, trim it neatly then strip it anew and solder it fresh. This way it looks clean and not abused.

As expected by now, third one now works like new.

I went back to the first one, clean it as the other two and got same result.

This is it! You don't even need any replacement parts! Isn't' it great!


TEMPERATURE SENSOR

OK, now you get bonus info: As I was tinkering with it and was getting ready to spend on spare parts I've realized that some info really missing about these stations. Temperature sensor is hard to get and very little info about technology used to measure temperature in these stations to replace them with generics.
If you have your temperature sensor open-circuit, you can make one from what you most likely have at home.
It is simple wire-type PTC. Thermal coefficient of it is slightly less than that of a copper or aluminum.I I'm guessing this is because added constant resistance of cable. Looking at metals electrical resistance thermal coefficient table it looks like many metals will work. Slight error of few degrees will not affect usability of iron. I set temperature by feel anyway.
You can wound one and pot it with high temperature silicone (hardware store, silicon for fireproofing) or other non-flammable cement like non-conductive compound.
When you trim your new sensor, at station terminals it should be 20 to 22 Ohm. It is pretty low resistance, this is why only two terminals have gold plated contacts. Other terminals are not worthy.


I hope this writing will save some of these wonderful, old stations and a lot of your time.

Cheers y'all!

:)
thank you so much for your post. I have same issue here. I havent tried your solution yet, but I believe mine will work as well. Thanks and Happy Ne year 2018 !
 

Mamo

Dec 31, 2017
3
Joined
Dec 31, 2017
Messages
3
Just heads up ..
I removed ribbon cable, i cleaned entire board, but issue still exist.
I even pulled up one side of each IC/transistors, cleaned underneath nothing changed..
 
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