The fix I see most 690 users doing is replacing it with the LED unit and never having to worry about it again.
Mine has held up with repeatable heavy abuse over rough terrain.
Sicass Racing makes some nice units with flush mount turn signals, very bright.
Do yourself a favor and ditch the stock POS.
* Assfault, Ass-Fault, Ms Ass, thier neighbors or friends, are not responsible for any incidents, accidents, or accusations, that might result from you using this forum in the pursuit of adventure greatness. Avoid taking ADV before bed time. Do not use if you experince faintness, dizzniess, inversness, difficulty urinating or an erection lasting longer than 4 hours. Thank you*