/diy/ - Do It Yourself

>>1660699
>$250
$250 might be worth a few minutes of tracing
one low-effort high-return assumption is that it's part of a shunt regulator in the fashion of Pic related. the shunt diode is a more or less constant-voltage device. the resistor value is selected to get that diode to dissipate some amount of power up to its rating when rectified mains voltage is applied. so, you find its shunt diode on the board, guess or determine its power rating by its package and/or markings, guess or determine its voltage by markings and/or by injecting current-limited dc into it until constant voltage is achieved, calculate the shunt current by I=P/E, derate by subtracting 30%, and calculate the resistance value by good old R=E/I. it's a good idea to go a couple or three notches higher on the resistance and probably go to the next higher power rating for the resistor, if it can be made to fit
>$0.12
for that price, you could buy an entire assortment, and determine the correct resistance empirically (starting from high resistance) until it works or until the foil lifts off the board

>>1660704
>>1660708
by convention, the tolerance band is separated from the value bands by a wider space. on 1/4W and 1/8W 1% resistors the difference is nearly invisible but here it is obvious. also note the metal deposit in the center, not present on other bands. therefore you're looking at a band that was silver or gold before baking
as for the value, most dyes darken toward brown when heated enough. 25 years at 80°C is probably enough

>>1660717
varistors would not be called out as C on the silk