https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-Not-working-rh-wite-no-power-now-has-blank-screen/m-p/622254#M120229 <P>Got no power to Rh issue. Also seen e74 error message in between. Now there is no power and screen is blank.&nbsp;</P> Thu, 23 May 2024 09:47:21 GMT MukeshPatel 2024-05-23T09:47:21Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-Not-working-rh-wite-no-power-now-has-blank-screen/m-p/622254#M120229 <P>Got no power to Rh issue. Also seen e74 error message in between. Now there is no power and screen is blank.&nbsp;</P> Thu, 23 May 2024 09:47:21 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-Not-working-rh-wite-no-power-now-has-blank-screen/m-p/622254#M120229 MukeshPatel 2024-05-23T09:47:21Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-Not-working-rh-wite-no-power-now-has-blank-screen/m-p/622391#M120275 <P><a href="https://www.googlenestcommunity.com/t5/user/viewprofilepage/user-id/552288">@MukeshPatel</a>, to test for proper power, you need a multimeter. Set the meter to measure AC voltage. Place one lead on R and the second lead on the C wire. You should see 24VAC +\- 5VAC. &nbsp;If you see less than 20VAC your system needs service to replace the step down transformer. &nbsp;<BR /><BR /></P> <P>AC Cooling Wizard</P> Fri, 24 May 2024 00:34:05 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-Not-working-rh-wite-no-power-now-has-blank-screen/m-p/622391#M120275 CoolingWizard 2024-05-24T00:34:05Z