EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: JuergenB52 on August 23, 2015, 12:26:33 pm

Title: Replace MLR-21 Heating Element with older MLR-20 Heating Element?
Post by: JuergenB52 on August 23, 2015, 12:26:33 pm

Hi,

has anyone replaced a broken Weller MLR-21 Heating Element with the previos MLR-20 Heating Element?

It looks like they use the same Heating Element, just with the lack of ESD protection?
The MLR-21 Element has a small Resistor on the PCB.

I can get one MLR-20 Heating Element for 50€ in Germany and would like to repair the MLR-21.


Thanks

Jürgen

Title: Re: Replace MLR-21 Heating Element with older MLR-20 Heating Element?
Post by: dom0 on August 23, 2015, 12:48:51 pm

Just curious: Why do these heating elements seemingly break rather often?

Title: Re: Replace MLR-21 Heating Element with older MLR-20 Heating Element?
Post by: Kjelt on August 23, 2015, 01:01:12 pm

What do you mean often.
Problem with these tiny smd heating elements is their more  fragile than normal size elements and they can not handle shock (using wet sponge instead of copper curls for cleaning)Also these stations had no auto shutdown, they were on all the time. The tips had lots of mass compared to modern ones.
The newer Weller WX SMD irons have auto sleep and use copper for cleaning.
The ultra tiny smd irons replace the heating element and sensor together with the tip.