- Category: electronicsanddiy electronicsanddiy
- Published: 16 February 2016 16 February 2016
How to fix common issues with cheap Harbor Freight Multimeters.
Fixing Harbor Freight Multimeters
Here in the US, Harbor Freight actually gives away multimeters for free when you purchase something else in their store. These aren't very good multimeters but they do the job for non-critical measurements. As an Electronics junkie, I can hardly resist free multimeters so I've 'collected' quite a few over the last couple years. I've found some of them come with some annoying defects out of the box. In this video (article) I'll show you two common defects and how you can fix them.
Harbor Freight Meter
Fixing a hard power switch
In some units, the power switch is very hard to move and is almost 'stuck'.
To fix this, start by opening the multimeter and finding the plastic part that contains the switch and the copper contact. Beware that I've found different models have slightly different shapes but the fix is similar; simply file away some of the plastic material as shown (be careful not to remove it completely). Put the pieces back together and it should be much easier to slide the power switch.
Removing the PCB (remove screws before this)
The Plastic Switch Piece (yellow)
Filing the Plastic
Fixing LCD display issues
In some other units, I've seen that some of the LCD segments don't turn on as expected. This is caused often by either a dirty contact between the LCD and the PCB or simply by bad positioning that might occur because of mechanical shock while in transport. In this case, you will have to remove also the pcb by removing the screws attaching it to the case.
Use a contact cleaner spray to remove dirt from the contacts. If you don't have a spray, then alcohol should do the trick as well.
Assemble the unit back together and enjoy your free multimeter.
Exposing the LCD Contacts
Using Contact Cleaner
Comments, questions, suggestions? You can reach me at: contact (at sign) paulorenato (dot) com