Manual:Wireless card diagnostics

R52, R52Hn and R52H Power Amplifier damage

If the cards are becoming too hot to touch, when inserted in a RouterBOARD, but are disabled - the PA might be damaged. This could be caused by user, or by manufacturing problem. To determine, must return to RMA for close inspectio.n

R52, R52Hn and R52H ESD damage

Improper grounding can cause ESD damage to wireless cards during storms or other ESD situations. To test if your R52 or R52H card is malfunctioning due to lightning/storm electrostatic damage, use a multimeter. In case the test fails with this method, the warranty doesn't cover it:
Damaged card:

Normal card:

Testing area close-up:

R52Hn card chain 0:

R52Hn chain 1:

DC shorted antennas

Also make sure that your antenna is DC shorted:
DC shorted antenna. This antenna doesn't need a Coax lightning arrestor:

NOT DC shorted antenna. This antenna needs a Coax lightning arrestor to avoid sudden wireless card damage. Note the OL (Overload) in the multimeter: