Polaris Sportsman Magnum Big Boss 335 400 500 HO 4x4 6x6 Dead Speedometer Odometer Gauge Fix Repair

Have a ~1999-2002 Polaris Sportsman/Magnum/Big Boss (probably applies to alot of other models too) with a dead speedometer/gauge unit? They were super common to have this failure, and they are very expensive to replace. When the gauge dies it causes the AWD switch to stop working. It can be bypassed, but it is annoying to not have speed or hours/miles functionality.
Often the failure is a caused by a bad battery, running the ATV without a battery, or a failed voltage regulator. The power transistor used for main power regulation in the speedo unit heats up and fails. In my case, it got so hot it melted the solder and fell out of the PCB. It is a Motorola TIP48 transistor, but can be replaced with almost any power transistor from a power supply.
Information on this fix came from this link, I just filmed my repair:
ka7oei.blogspo...
Hope this helps!