Are we being punked?

August 18, 2009 8:53 AM

In order to fix a malfunctioning printer we have been told to unplug it and hold down the power button for one minute to release static. Are we being punked?

My wife is working through the scripted advice generated by HP on addressing an ink jet printer that is not functioning correctly. Most of the steps are to be expected (clean rollers, check paper feeds, etc.) They also ask her to unplug the power and USB cable and hold down the power button for 1 minute to release static. That was the first I ever heard of using that as a fix. When I google it, there are people who recommend it for fixing other electronic devices such as laptops that won't boot (first remove the battery then hold the power button for 1 minute).

Does this actually do anything or is it electronic device voodoo? Where is this static that is supposedly being released and how does holding the power button release it? And since the device is unplugged and is not grounded where is this static going? I am not an electronics expert and I would love to hear from those who are.

posted by Tallguy to computers & internet (7 comments total)

You are not being punked.

Most modern devices have large capacitors in them which can remain charged for a long period of time. They can maintain a piece of volatile memory that might, in fact, be causing problems for you. By holding down the power button, you're discharging the capacitors completely.
posted by teabag at 9:05 AM on August 18, 2009 [1 favorite]

Holding down the power button usually means to override the soft on-off button and do a hard shutdown. Not sure if that applies to printers. Sounds like you just have a crappy printer and doing a reboot fixes the problem for a while. I doubt its static related.
posted by damn dirty ape at 9:05 AM on August 18, 2009

It's not entirely voodoo; the idea here is that the power supplies on electronics often include capacitors that can hold a charge even after the device is unplugged, and forcing the power supply to engage by keeping the button held down will allow all the stored charge to drain, ensuring that the thing is really off. If you'd like to see this for yourself and have a multimeter, you can do it with a large wall wart; just plug in and check the voltage across the leads, then unplug it and check again. With no load on the power supply, you should still notice a voltage that is nearly as high as when the thing was plugged in, at least for a few seconds. It's not "static," which is kind of a meaningless term, it's residual charge that bleeds off over time and can be made to bleed off faster if it's applied to a circuit. Theoretically if you want to really, completely reset something this is a way to do it. In the real world does it ever actually fix a problem? Not in my experience.
posted by contraption at 9:16 AM on August 18, 2009 [2 favorites]

This works on a lot of electronic devices - recently I have used it to fix a washing machine and a mobile phone.
posted by EndsOfInvention at 9:17 AM on August 18, 2009

My ancient HP laser printer requires the same procedure now and then. I discovered it by trial and error.
posted by miyabo at 10:47 AM on August 18, 2009

This is how you reset the PMU on apple laptops (see here), which has a whole host of effects you can't get by just rebooting it. It's possible the printer does something similar when you hold the power button.

If HP support says to do it, it's probably worth doing. I'm not sure why they would bother telling you otherwise, their time is too valuable to waste giving advice they know won't help.
posted by cj_ at 3:20 PM on August 18, 2009

That does indeed occasionally work to solve strange problems. It "drains" the power supply. It's like holding the toilet lever down until all the water runs out of the tank.
posted by gjc at 4:58 AM on August 19, 2009