I emailed Hi-Link about the HLK-PW01 power supplies that @rmh, @yannik-mündler and myself purchased. These are the power supplies with a removable bottom.

I sent the following email to Sunny at Hi-Link (contact info: http://www.hlktech.net/contact.php).
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Hello,

Are the two HLK-PM01s in the attached images genuine Hi-Link parts? A major difference is the part on the right has a bottom cover that is easily removable.

I bought the part on the left from an Aliexpress seller in July 2018. The part on the right was bought from the same Aliexpress seller in May 2019.

Thank you very much for your help.
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Here is Sunny's reply:
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Now all of our module are use new version .

The one you bought on 2019 is the new version, the old version is not used yet.

By the way,May I know you are the final user or the reseller?

If you are worried about it,you can buy from our website www.hlktech.net or our Aliexpress store https://hlktech.aliexpress.com/store/211069 directly.
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I went to the Aliexpress page in their email and found the HLK-PM01 page. On that page they say:
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Recently,there are many fake module in the market,in order to Standardize the market environment,keep benifit for the customers,We,Hi-Link,changed our module to the new but more quality version,the back of new version is show as the following picture,currently,the old version and new version were sent random,please pay attention to that!thank you very much!
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They also show images of the previous version (which we are all familiar with) and the new version (with the removable bottom).

So, it appears the HLK-PW01 power supplies with the removable bottom, from a reliable vendor, or directly from Hi-Link, are genuine Hi-Link power supplies.

Below is my two images of the bottom of the two genuine power supplies (old on the left, new on the right).

@dbemowsk I tried a similar clip, but it didn't work (the fuse still blew when I soldered it). A small piece of wet sponge and a small clip to hold it around the wire lead work the best for me.

I recently ordered 10 HLK-PM01s from WAVGAT Store on Aliexpress.com. The photo on their advertisement is the same, and looks like you expect, for a genuine Hi-Link product. The products I received recently were the same as @rmh received. The last time I ordered these in July 2018 from WAVGAT Store, I received the same product as their photo. I think I am going to open a dispute and see what happens.

I found some varistors at the best electronic component store in the area. They had a wide variety of voltages. One was 120v (part number CNR-07D121K). We have 110v AC (measured) here. On the outside of the plastic bag with five parts was a store printed label that included "120v1ma +- 10%". If that 10% applies to the max voltage, then that may explain the failure of my varistor. 120v * .9 = 108v. Perhaps it was working just fine, but it was at the low end of the tolerance range. The next voltage up on the supplier's shelf was 150v. The more I learn about these things, the less I think I know. A datasheet I found was 24 pages long!

Replacing them with better parts is definitely a good idea. Unfortunately, I'm limited in what I can buy locally. I have to order them from another continent if my local electronics store doesn't have them. I may just cut them off the PCB and replace them at a future date.

Has anyone else seen a varistor/MOV failure in a power supply?

I recently had a 120v varistor fail on a HLK-PM01 breakout board (thanks @sundberg84 !). The varistor now shows a resistance of 262 ohms. The low resistance took out the 200ma AC input fuse (as expected).

The odd thing is I have six nodes powered by HLK-PM01 breakout boards and each board has exactly the same varistor. Only one has failed, so I doubt if it was an AC power problem. We haven't had any lightning strikes and the APC power supply on my PC didn't record any power problems. All of these nodes have run for several months without problems.

Has anyone else had a varistor fail like this?

I'm really nervous about this because in one month I'm going to be away from the location where these nodes are installed for about six months. The nodes control heat pump systems which will control the humidity while I'm away and the home is closed up. I'm considering just removing the varistors rather than risk a bad varistor taking a node off line.

These are the varistors that I bought on Aliexpress: https://goo.gl/2qhnaR

Below are photos showing the varistor and its markings.

This looks like a great PCB and I'm interested in ordering a few from DirtyPCBs, however OpenHardware.io shows this project as "Work in Progress". Are there any plans to do additional updates to this PCB?

Is it reasonable to hand solder the SMD components on a board like this?

@nca78 said in Combining orders at OpenHardware.io?:

Just make a paypal donation of the PCB price difference to MySensors for that. Maker of PCB will lose their share but it's pretty small and it ends up given as donation to MySensors most of the time.

Excellent idea!

@hek,

Thanks for the info, that is what I suspected. It occurred to me that I could download the files for each PCB that I want to order, then upload the files to the PCB manufacturer and skip ordering from OpenHardware.io. However, I've never ordered PCBs by uploading files, so I'm concerned that I might make a mistake and end up with a bunch of unusable boards. Also, I have no desire to cut the owner of OpenHardware.io out of any well deserved revenue from that website.