It is highly recommended to source your test point diagram from a reputable and paid service to avoid irreversible damage.
Maybe I should search for "LG K52 test point" on XDA Developers. results.
Let us know in the comments if you encountered any specific issues with the K520 model.
: The test point is usually a small gold-plated circular pad near the CPU or the battery connector.
The LG K52 Test Point method is . It is a vital skill for mobile repair technicians but is not recommended for the average user.