It is possible that the grounding wire is broken or the P.W.B. is defective.
Check that the grounding wire is not broken.
When the grounding wire for wrist strap is broken also, the HIGH lamp will be lit. (For the check method, click here.)
[Check of HAKKO 498 Grounding Wire]
Connect the grounding wire to the HAKKO 498 and hold the pad with a clip.
If not broken
The LOW lamp is lit.
If broken
The HIGH lamp is lit or the lamps light alternately.
[If the grounding wire is broken]
Replace the grounding wire with a new one.
Product number of grounding wire... 498-1 *
Purchase it from the shop where you purchased the main unit.
[If the grounding wire is not broken]
Send it to the place of purchase for repair.
*We recommend that you should make sure that no abnormalities are found in the wrist strap before sending it in for repair.
*Clearly stipulate “repair only” or “repair and calibration” when sending it in for repair.
Replace the grounding wire with a new one. 
