Weller EC2002M

[Mike6158]

Well crap... About an hour ago, out of the blue, the power went off. I was right in the middle of cussing... I mean soldering, som chip resistors to a board that I've been waiting on. They finally turned the power on my my soldering station has shot craps. It won't heat the iron. The display works. They don't make the station anymore. What the heck would make it shoot craps? I've got a stack, literally, of circuit boards that I want to assemble... crap...

[Dean Huster]

No intention of a lack of emphathy here, but things like that sure make me like my little fifteen watt Antex iron a lot. I wonder whether it was just a fluke that the iron shot craps and would have anyway with the next cycling of the power switch or the power company truly lived up to their name and provided you with a bit more than the iron could handle on a momentary basis.<p>Dean

[cato]

Are you sure there isn't some sort of reset button you can press or fuse you can replace? Beyond that, I assume there is some sort of power transistor that regulates the heating power delivered to the soldering tip. I suppose a power spike could have let the majic smoke out...

[Mike6158]

I like my gee whiz iron so I'm going to see about fixing it or getting it fixed. I lost power again right after I posted (which is really odd. I don't even lose power in TRW's much less calm days) so I didn't get a chance to open it up. The display indicates 326 which is probably some kind of trouble code. I'm going to do an online search to see if I can find a manual. Maybe the code will point me in the right direction.<p>I need to see if I can find my "plain ole" iron. I've had some boards ordered for almost a month (Chinese New Year got in the way) and they finally showed up... I want to play with my toys...

[Dean Huster]

Surely Weller will send you the schematic, parts list, etc. and maybe a real operators' manual as well(er). I've found that most companies are willing to help you out as much as possible, providing their manuals aren't 175 full-color pages along with 28 pull-out diagrams.<p>Dean

[Mike6158]

So far all I've found is a cheesey manual. <p>Anyone here have any experience with Xytronics hot air equipment? I hesitate to "do" hot air since I know nothing about it. Just in case...

[Mike6158]

Ah... the plot thickens. Starting at the xfrmr... 120VAC in / 26VAC out. There is an LM340T5 that's pretty warm to the touch and opposite of that (board location) and connnected to the iron is a L4004F91 which is apparently a triac made by Teccor (couldn't find an F91 though). The triac has a large heat sink and it's stone cold. Possible because the iron is bad but since this thing crapped out when the power came back on, who knows. Here's the fun part... They covered up the id on a part that looked suspiciously like a PIC (4mhz crystal and two caps looked familiar connected to it looked familiar). It is a PIC 16C57-XT/SO. I'm guessing that it's for the display/temp control/thermocouple interpretation. Most of the parts are SMD's and it's hard for me to identify them. There is a MAX406 OpAmp... It's a busy little board...<p>[ March 05, 2005: Message edited by: NE5U ]</p>

[k7elp60]

I used to work at a local electronics distributor. I recall we stocked Weller soldering stations, and some spare parts.
I went to the Weller websit:http://www.cooperhandtools.com/brands/weller/ and scrolled down and they listed replacement circuit boards for the EC2002.
I also have a TECCOR data book that lists the L4004F91. If you need the specs let me know.

[Mike6158]

Thanks.. I might want the specs. It occured to me that the triac might not be warm because the iron might be messed up.

[philba]

I'm sure you've thought of all this but I'll say it anyway...<p>Have you checked the output of the triac and/or continuity of the heating element? If the iron checks ok, I'd put a scope on the triac gate. There should be a 120 hz phase control signal. Some irons have a ceramic element that can be fairly brittle. Of course, there may be a fuse for the iron circuit alone. I'd be suprised if the power glitch blew something in the control circuit.<p>Phil

[Mike6158]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by philba:
I'm sure you've thought of all this but I'll say it anyway...<p>Have you checked the output of the triac and/or continuity of the heating element? If the iron checks ok, I'd put a scope on the triac gate. There should be a 120 hz phase control signal. Some irons have a ceramic element that can be fairly brittle. Of course, there may be a fuse for the iron circuit alone. I'd be suprised if the power glitch blew something in the control circuit.<p>Phil<hr></blockquote><p>Nope... I haven't thought of that but I do agree that it's hard to believe a little power spike did something to the circuit or triac. Especailly since there are other more sensitive components that are apparently working fine.<p>It's a PITA not having a schematic...<p>Ok... the heater is an EC234. It has 3 wires. Green, white, and yellow<p>Green - White: open
Green - Yellow: open
White - Yellow: 13.2Ω<p>Haven't put a scope on the triac yet.<p>[ March 06, 2005: Message edited by: NE5U ]</p>

[Mike6158]

Well I caved in and sent it to Cooper for possible warranty repair (I doubt it). I'm on the road tonight (west Texas)... I leave for D.C. on Friday and won't get back until next Wednesday so I won't be doing any soldering anyway... Kind of bums me out... I think that I could have fixed it...

[Edd]

Phil:
I have several of the Weller stations but not one of your newer numbering with adjustable temp and temp readout display, however I believe I have a couple of the Handles / heating element / solder tiplet, less the control base and its electronics.
Since Weller has a good thing going, I can’t see any MAJOR design revision (s) to preclude troubleshooting of what you have. However, don’t expect a schematic with proprietary design info, but one should be able to troubleshoot circuitry and fall back on subassembly replacement if required. The units use an AC line fuse for the power so if U are getting a display, its good !. The fused power transformer provides 24VAC (27.5VAC U/L) to the control electronics as well as the heating element of the iron. I don’t know if the “326” reading is redundant after a total power supply power down and discharge. I certainly don’t expect any degree of sophistication in the control electronics as to incorporate failure mode error encoding.
I think your series of unit might possibly also have been available in a cheaper version that only displayed temperature and was dependent upon their conventional temperature control technique vice the controlled triac method.. Refer to the O and M versions on: ( The whole ADOBE page of part numbers is active to info to the corresponding stations)<p>http://www.arcade-electronics.com/welle ... rtscat.pdf<p>You did give the part number of EC234 for your heater and a CONTROL-F on the voluminous Adobe document will find that element used extensively thru-out the line. Also, with the design that they are using on their heating elements, they use circular wound nichrome elements. If that unit happens to use the bayonet lock connector with three connections, the terminations are:
Green is the “Earthen” ground that is connected to the metal housing of the iron, white is the 24Vac ground and yellow is the switched 24Vac to the heating element. So yes, your heating elements integrity is confirmed, with that 13.2ï

[California Techie]

As a new reader of the magazine i found this group address listed inside and was reading back posts and found some topics of interest to me.
i also have an older Weller station, possibly 1997, that is erratic in heating at times.Sometimes after sitting in its holder it will be cold when I pick it up to use. Any body else experienc this and what might most likely be the problem. Now when it has problems i work between this unit and my plain old soldering iron .
TIA Rex

[terri]

Slight sidetrack: I'm familiar with the electronic term PITA, but what's TRW mean?<p>NE5U: "I don't even lose power in TRW's much less calm days)."<p>From context, I gather the "W" means wind, but...<p>I'm sure it's obvious and as soon as you tell me I'll smite my forehead in the classic "dope slap" and say, "But of course! I should have known!"<p>I've been using the term "BMF," but nobody's asked me about it, so I guess this is another well-known acronym.<p>[ March 18, 2005: Message edited by: terri ]</p>