Hakko FX-888D-29BY Soldering Iron Repair
This is my Hakko FX-888D-29BY soldering iron. The soldering handle for it is a FX-8801. I have had it for nearly three years and it has been a great iron. As you can see in the photo above, the temperature somehow is not working right – it’s nearly 180⁰F off! I immediately thought something was wrong with the heating element, then went to the Hakko website and ordered a new one.
Everything else around here is conking out on me! I was watching my Sanyo 42” LED/LCD Flat screen TV, and the backlight went out on it. So I started to vacuum the dust off of it so I could remove the back and my vacuum cleaner quit on me, and tripped the breaker!
I was already replacing a charge port in a Kindle Fire 2012 2nd Edition when my TV and vacuum cleaner quit. So when I started working on the Kindle again my Hakko soldering iron wasn’t getting hot enough. So, considering the bad recent events, I assumed the worst and ordered the new heating element.
I started wondering what else was going to happen. I was glad that my little Weller SPG40 soldering iron was still working well, because I am going to need it. You can see the front of the Hakko board in the above photo, and a photo of my Weller iron below.
I took more photos of the iron while disassembling it, but I can’t find them. So I had to disassemble the iron again to retake the photos that I lost. That is why some of them have a later date than the others.
I couldn’t find anything wrong with the iron except for the temperature. The photo above is of the back of the board. The red wires on the board, 26V and 0V, are coming from the secondary of the transformer.
The black wires, H1 and H2, go to the heating element through the plug. The two white wires, SE1 and SE2, go to the sensor in the heating element through the plug. The red 26V wire measured about 25V. The Triac, Part #BTA06-600C, tested to be good. So did the Nichicon e-caps. Everything looked ok!
In the photo above you can see the heating element, Part #A1560, and the terminal board #B2028, removed from the iron’s handle. The grounding spring and white fiber tube that protects the contacts on the heating element are also removed.
All of the wires are soldered on both sides of the board. The two wires with the blue fiber heat tubes are for the sensor. The two wires with the red fiber tubes on the other side of the board are for the heating element. The wire with the black shrink wrap is the ground wire that the grounding spring plugs into.
The other four wires connect with the heating element and sensor here on the terminal board and run through the cable and connector to the mainboard in the soldering station unit.
All of the solder joints look good, but leaded solder will be better. The heating element is removed from the terminal board. The heating element and sensor checked to be good when I checked them, onboard and offboard.
You can see what I measured in the next photo. The measurements that I wrote in pencil are what the old element measured. The new heating element and sensor measured about the same.
In the above photo I’m setting the new element onto the board. According to the instructions, the heating element needs to be 64mm from the edge of the terminal board to the end of the heating element. In the next photo you can see the measurement.
My little Weller soldering iron is doing a great job! It doesn’t have as many types of tips to choose from as my Hakko does, but it does a great job with the tips that I do have.
I’m glad that I have two soldering irons, besides my big Weller D550 240/325 watt soldering gun. It is a good idea to have many soldering irons in case one is having trouble, or the job requires a lot of heat. My Weller D550 is a monster, and laughs at heatsinks. Lol!
After soldering both sides and trimming the heating element leads, I can turn the terminal board over and start soldering in the other wires. Then turn the board back over and solder them on the other side.
In the photo above, the board is together and cleaned with the white fiber tube and ground spring installed. In the next photo the heating element is installed back into the handle and ready for a tip to be placed onto it.
In the next photo you can get a look at the transformer and the back of the main board. The Microcontroller used in the station is a Renesas, Part #R5F1007CA.
The components look like top quality, and the soldering looks top notch – I was impressed. The Varistor on the small Primary HV board, Part #V271U, is a “ZNR” Transient/Surge Absorber (Type D). A close-up photo of the HV board is below.
In the photo above I am calibrating the temperature. I also changed my Hakko station and Fluke 87V meter over to degrees Celsius. Most people now-a-days use Celsius anyway. And since I was a mechanic for a while earlier in my life, I am used to using both SAE, and the Metric system.
If you notice, the temperature is still off by about the same amount! There was nothing wrong with the original heating element! 350⁰C – 268⁰C = 82⁰C × 1.8 + 32 = 179.6⁰F. Somehow I must have messed up the calibration of the iron and didn’t even notice it. Or maybe there was a glitch or something, I’m not sure.
It’s about the way things have been going lately. Because of everything else quitting on me, I just assumed the worst for my Hakko iron and ordered a new heating element when it wasn’t necessary.
But, I’m not mad about it. It has been fun, and also allowed me to have another article to write! So, that’s not a bad thing, right?
In the photo above, you can see the thermocouple touching the soldering tip. It’s actually closer to the tip here than it was with the original heating element.
The Hakko soldering station here is set to 350⁰C, and my trusty Fluke 87V is measuring the temp at 353.5⁰C. That’s good enough for me.
This repair is finished after I put the cover back over the soldering station. I’m going to keep the old heating element for a spare in case someday this new one goes bad.
The photo above as you can see is a close-up of the ZNR Varistor. A close-up of the Triac is below.
Here is a look at my new Circuit Specialists 853B SMD Preheating station. It will make SMD rework much easier. I hate needing to crank up the air temp and air flow because the board is sinking so much of the heat. That also makes it easier to blow tiny components into never-never land.
Now it’s time to repair my TV, and then take a look at my vacuum cleaner. I hope yall enjoyed this article. See you in the next article.
Robert Calk Jr., is a Hobbyist from the U.S.A. that loves Electronics Device Repair. Please leave any comments or suggestions that you may have below. Thanks.
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Please check out his previous repair article below: