Weller WTCPT Iron - sometimes doesn't heat up

Discussion in 'Radio Circuits, Repair & Performance' started by KB2FCV, Sep 9, 2016.

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  1. AA5CT

    AA5CT Ham Member QRZ Page

    .. picked one up at Heathkit, used, about 1978. It didn't work - fuse (inside) had blown!

    Have since blown (and replaced) the fuse again, doing heavy soldering (making six meter duplexers from 1 5/8" Heliax) ... still in service today - these things just won't die!

    I have a habit or rapping the tip against the base unit to discard old solder - this practice killed two temp-controlled digital-display Wellers, but the one with the magnetic temp "sensor" still works.
  2. W9GB

    W9GB Ham Member QRZ Page

    In 2002 / 2003, Weller North America (then owned by Cooper Industries of Houston, TX) had to change its entire production / manufacturing to comply with global RoHS compliance (No Lead, Pb). This meant retirement of any and all production equipment (some dating back to Weller’s start in Easton, PA) dealing with leaded soldering or machines handling lead parts.
    Cooper Industries took that opportunity to close its North & South Carolina production and relocate to new facilities in Mexico, adjacent to many of its OEM suppliers (Carling switches, Power cords, transformers). Many 20th Century designs (EC-series, WCC100, some Ungar, others) were retired and New models (Silver Series, WS, WSD) already RoHS compliant and designed in Germany introduced at Millennium.
    At that same time design of the EC234 (plug-in) and TC208 (wire-in) 24 VAC heaters for TC-201 and EC-1202 soldering irons were CHANGED as part of RoHS.
    The Heater’s Cylinder was SWAGGED, increasing its Diameter.
    SEE PHOTO of EC-234, BELOW. NOTE the Swag at Mid-point of Cylinder.
    This requires a NEW BA-60 Barrel Nut, that holds the soldering tips to these irons.
    The New BA-60 are in Plastic Packaging that is Dates 2003 or Later.
    OLD Packaging dated BEFORE 2002, or in Yellow Manila Envelopes are OLD Nuts
    and Will Not work with the New RoHS Heaters.

    Last edited: Apr 29, 2019
  3. WB2GCR

    WB2GCR Ham Member QRZ Page

    It's almost certainly the switch, the magnetic switch. I've repaired quite a lot of them with this problem.
    You can troubleshoot it easily.

    The wires are thin, so care is required.
    Take the screws out of the round part holding the tip to the blue plastic handle.
    The 4th screw holds the metal part that holds the wires as a strain relief, don't pull that one.
    Slide the heater assembly forward a bit...

    Now, in a quiet room if you take the tip in and out you will hear a slight click, as the
    magnet pulls the switch in. That says if the mechanism still moves.

    Well, the contacts may be arc'd into submission.
    I have removed the little plastic cover and cleaned the contacts.
    Sometimes that is fine, but it's 50-50.

    Best bet is to buy a new magnetic switch assembly, I've gotten them on ebay.
    or then entire old style heater assembly with the switch... or as noted, a new style
    handle + heater assembly...
  4. W9GB

    W9GB Ham Member QRZ Page

    Electrical switches have a finite life, stated in number of operations.
    The Weller SW-60 Magnistat switch were originally rated for ~ 100,000+ operations.
    That number has improved with contact plating and capacitor placed across the switch leads.

    When you acquire USED/Surplus TCP stations, SOME stations were used on production lines (rarely turned off). IF you have 1 or 2 switch cycles each minute (idle), then the switch life is ~100,ooo minutes or ~ 1666 hours (70 days). This approach is less common today. When I repaired surplus TCP-1 hand-pieces in early 1970s (Collins production surplus), everyone had some SW-60 issue ... they were used on production/re-work lines for 1960s S-Line and Apollo program, often wired to 24 VAC line (rail) on workbench.

    The “4th screw” for the metal strap/strain relief inside bakelite was only used on North American TCP-1 models from 1965 to 1981 with wired-in heaters (TC-208, EC-208). The very early EC models (1976-1981) also used this design. This is the “quick method” for the hobbyist to identify which Weller hand-piece they are repairing.

    In 1981 Weller re-designed the North American soldering iron’s for TCP & EC series (TCP-201, EC-1201 hand-pieces) to use “plug-in” heaters (EC-234), 1981 to present.
    In Europe ...
    Weller manufactured their soldering stations in United Kingdom and eventually Germany.
    These models have DIFFERENT Design, due to Electrical Certification and Standards,
    BUT still use the Curie switch technology and 24 VAC heater.

    European Magnistat TCP irons.
  5. K4TL

    K4TL Ham Member QRZ Page

    I have the WTCPT soldering station which is maybe 30 years old. It heats, but I think it over heats, and it doesn't "click" any more, which indicates to me that it's not regulating the temperature of the tip. All of the the troubleshooting steps in the manual were OK and I've tried a new tip without success. Any suggestions from the experts would be appreciated.
  6. W9GB

    W9GB Ham Member QRZ Page

    There are ONLY three (3) Major Parts with Soldering Iron of the TCP-series.

    1.) 40 watt Heater (EC-234)
    2.) Magnetic Switch (SW-60)
    3.) Soldering Tip with its Ferrite Alloy Plug (PTx-7)
    Use 700° Tips.
    For Amateur Radio usage the PTB-7 is my recommendation, PTA-7 for PC board work.

    The “Click” is the Magnetic Switch (Magnistat) SW-60.
    Like any switch, it has an expected life (On-Off cycles), after 10+ years of continuous (24x7) production bench operation (in 1960s) the SW-60 or heater usually fail.

    DIY Replacement of SW-60.
    REQUIRES Ability to remove socket pin (207437-3, nickel plated) from black insulator.

    SW-60 Instructions

    Proper Disassembly of TC-201T Handpiece

    You have to Fabricate (Bobby Pin) the Tyco/Amp extractor tool 91136-1

    That is outlined in Disassembly of Handle
    Last edited: Sep 20, 2020
  7. K4TL

    K4TL Ham Member QRZ Page

    W9GB, thanks for your assistance. I will attempt repair, the WTCPT is too expensive to throw away!
    Curt, K4TL
  8. W9GB

    W9GB Ham Member QRZ Page

  9. VK6ZGO

    VK6ZGO Ham Member QRZ Page

    The switch is burnt, & welded together, so the iron will continue to get hotter, until it damages the tip.
  10. K4TL

    K4TL Ham Member QRZ Page

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