[TIP] Pryon PC rebooting when laser printer used

[fincoder]

Had a weird one. Home office with 2 x PCs and a LAN connected Brother laser printer.
When either PC sends a print job to the printer, one particular PC suddenly reboots.

Tried drivers, printer firmware update. Nothing fixed it. PC taken back to my workshop and working fine, couldn't find a problem.

The PC is a Pryon tower which is the white-box brand for retail chain Harvey Norman.
Intel i7 8th gen, GTX 1060, MSI motherboard, Bitfenix BPA600 "600W" PSU.

Replaced the PSU with Antec VP700P 700W with 80 Plus certification.

Customer reports several days of use, no more sudden reboots. Recording in this forum in case it saves someone time in future. I suspect the home office (garage conversion) electrics might have had a slight voltage fluctuation when the printer fired up, tipping the poor quality PSU over the edge.

 

[nlinecomputers]

I'd put a UPS on it as well. Filters out dirty power and should fill in for micro brownout caused by the big current draw of a laser.

 

[fincoder]

Good idea. If there are any micro brownouts it might degrade any PSU over time, although I have a feeling that it shouldn't matter with decent PSUs (e.g. any with 80 Plus).

 

[Sky-Knight]

Yeah that's got to be power. I'll bet if you put one of these on the outlet that powers that machine: https://www.amazon.com/Power-Gear-Receptacle-Indications-50542/dp/B002LZTKIA

You'll find it's miswired. The only time I've seen stuff like this happen is when there's a large current draw on the same circuit while the computer is either missing a ground, or the hot / neutral are swapped. Your client needs an electrician, not a computer tech!

*Edit* Didn't notice you were in Australia before I posted, you'll need the correct tool! Though it's much harder to goof up 220v.

 

[MudRock]

Good idea. If there are any micro brownouts it might degrade any PSU over time, although I have a feeling that it shouldn't matter with decent PSUs (e.g. any with 80 Plus).

I've seen some 80 Plus Plat suffer from crashes caused by power dips.

Lot of good comments here; Check the power outlet, check the power supply. I'd err on the side of either an underpowered PSU, a softening PSU, or Active PFC on the PSU paniccing and shutting off. Could be motherboard VRMs, or even a ground fault scenario.

Lasers are terrible for causing local brownouts. The worst was the old Phasers (Then Xerox Phaser), the wax block units. They SCREAMED in the manual you couldn't put them on UPSes. If you DIDN'T, or didn't UPS everything else out, you'd brown out entire locations during power cycles, crash stuff, shut off debit terminals. Worse off, if you lived in an area with crap power, if the thing even blipped for power, except when caused by itself, it would do a purge and rewarm cycle. One location could go through 12-16 blocks of ink a week from all the power hiccups in the winter.

 

[nlinecomputers]

Good idea. If there are any micro brownouts it might degrade any PSU over time, although I have a feeling that it shouldn't matter with decent PSUs (e.g. any with 80 Plus).

No power supply can provide power that isn’t there. That was my point.

 

[fincoder]

No power supply can provide power that isn’t there.

They can for a very short power drop. When a standby UPS switches to battery, there's a short power cut that modern PSUs handle in their stride. I assume because of capacitors.

 

[Sky-Knight]

Yeah a good PSU will have large enough capacitors on the AC inlets to supply power for a few milliseconds. It's usually enough to survive a hiccup or two, but not much more.

 

[timeshifter]

I'd put a UPS on it as well. Filters out dirty power and should fill in for micro brownout caused by the big current draw of a laser.

But be sure the laser is not on that UPS. That will cause the problem you were seeing, that was my first thought when I saw your post title.

 

[fincoder]

Yes, first thing I thought of was the laser printer on the same UPS, but no they aren't using any UPS.

The customer reports still no recurrence of the problem after replacing the PSU.

 

[MudRock]

They can for a very short power drop. When a standby UPS switches to battery, there's a short power cut that modern PSUs handle in their stride. I assume because of capacitors.

Yes, modern power supplies not only have capacitors for filtering noise, they are also there to "even" the power out outside general noise, but also for momentary dips/brownouts. Quality of the power supply as well as how loaded down you have the PSU will determine its ability to "buffer" a dip.

It's one of those. You unplug the power, and it is still there for a second before going off.

Sounds like a weakening PSU; Likely caps starting to leak/burn off/dry out.

 

[fincoder]

I just pulled out the PSU from the ewaste and opened it up. One of the medium sized caps is ever-so-slightly bulging, the top is slightly convex whereas the others are perfectly flat. Possibly another few months and the PSU wouldn't work at all.

 

[HCHTech]

I'd put a SMART UPS on it as well.

FTFY. If you are looking for brownout protection, standard UPS units don't do that.

 

[fincoder]

By 'SMART' do you mean line-interactive or online? By 'standard' do you mean standby/offline?