Surface Book Taskbar Previews close too quickly (when battery status updates)

Hi Loren,

I only have an SP4, and most of the people that I've corresponded with also have SP4's, so it's a bit difficult to pull together what may be going on with SB's, but your analysis is very valuable. Would you mind contacting me at ******@pmFAQtory.com? If you have the time, perhaps you might be able to help us to do some testing on your device, put the finishing touches on my document, and help us to drive Microsoft to resolve this for all of us.

I've corresponded a bit with David Catuhe, Principal Program Manager for Windows & Devices at Microsoft. He initially told me that he had found the bug reported somewhere within Microsoft, presumably in an internal database, and that they had reproduced the bug and someone was investigating it. He even mentioned that he thought that a fix was targeted for the Creators Update in 2017, and asked that I ping him every three weeks for a status update. Subsequently, I went to a Microsoft Store and was able to swap my 36W original SP4 power adapter for a 65W one, and that immediately resolved (or masked) the bug on my SP4. I also ordered one of these 36W Kingdo clone power adapters: https://www.amazon.com/gp/product/B01GPFM5GA/. It, too, worked, either resolving or masking the bug. I told David that swapping out power adapters had fixed the problem for me.

But I then considered the possibility that the power adapter might not be the whole story. I've been collecting data behind-the-scenes from various users plagued by this bug. I'm cautious to draw conclusions, so please remember that my document is just a draft, and could contain erroneous conclusions.

If you're saying that you're confident that you've been able to send 15V of steady DC with no voltage spikes that could trigger power state changes to your SB, then I have to wonder why the 36W Kingdo adapter resolved the bug on my SP4. It's very clear that PBT_APMPOWERSTATUSCHANGEmessages cause the focus to be usurped from the taskbar, which causes thumbnail previews to disappear. The question is, What causes these messages?

One possibility is voltage spikes from defective power adapters. Another is a design flaw in the Surface device's power management circuitry or battery (batteries). Another is a bug in the ACPI driver. Possibly another is a firmware bug. Whatever the problem is, it's power management-related. We can only do so much. We need Microsoft to figure this out. Since the bug has existed on the platform ever since the SP3 was released, but it *hasn't* affected most SP3's/SP4's/SB's, from what I gather (and I've asked many users), why us? What's different on our devices or power supplies?

Our crude debugging efforts are limited by the fact that we don't have a deep knowledge of the Surface architecture. We have no idea what all of the interacting drivers, firmware, and other mediating and moderating variables are. So given this, how can we collect enough data to get Microsoft to not drop this and pretend that it's not a real and serious (show-stopping) bug?

Nothing has aggravated me more than Surface Support saying that they couldn't reproduce the bug, until David told me that someone else within Microsoft had.

All I can tell you for certain is that on my SP4, the nanosecond that I plugged in the 65W Microsoft adapter, and a few days later the Kingdo 36W adapter, the bug disappeared instantly.

I invite you to contact me if you'd like to help us close this nightmare out.

Thanks,

Steve

This bug is caused by your power supply. You need to get it replaced.

Unbelievable.  Thanks, Steve.  I switched over to the extra PS I bought for travel.  It's a 65w model 1706, which is designed to accommodate the Surface Book i7 dGPU models, but works fine for the lesser siblings as well.  The problem completely goes away with it.  I don't know if *all* the model 1706 power supplies are problem free, or if I just got lucky, but I'll definitely seek to get the model 1625 PS that shipped with my SP4 replaced.

I would have NEVER guessed this to be a problem with the PS, but considering how integrated with the OS modern charging systems are, I shouldn't be surprised.

Best regards,

Chris

Steve,

I'm pretty sure the problem is not "A spurious signal from defective power supplies". My Surface Book shows this problem on pure DC power from the (huge) batteries in my off-grid house.

If it sees 15 Volts like Microsoft's 65 Watt power brick provides, the charging circuit can keep up with most CPU loads, and only rarely switches among batteries "charging" or "fully charged" or "in use". If the Surface batteries are really low, it seems easier for the system to show them as "charging" consistently. As the supply voltage drops or the CPU load increases or the Surface batteries get almost full, the state transitions get more frequent.

Right now, if I open the battery display and leave my mouse stationary, both batteries show "fully charged" constantly. Mouse over the tray icon for a minimized Explorer window and it hits one of the batteries. Wait for both to return to "fully charged", and mouse over the icon for Firefox - it hits both batteries. Position the pointer over a taskbar icon, wait for "fully charged", and then move the mouse to show the preview - the sudden CPU load hits both batteries and closes the preview!

The real problem here is that changes in charging state hide the taskbar previews. This has been happening since Win 7 came out, on many brands of notebook with totally different power bricks and charging voltages. Microsoft chose to blame the other vendors, and never fixed the real problem.

Since it seems they are unwilling or unable to fix the real problem, providing a 15 Volt power supply to affected users would be Microsoft's quickest way to reduce (but not eliminate) the appearance of the problem. I wish you luck with that! But I'm pretty sure all you need as data is whether a user has the 12 Volt or 15 Volt supply. Any 12 Volt supply (at least in my experience) will trigger lots of disappearing taskbar previews.

Loren

All,

This bug is caused by your power supply. You need to get it replaced.

See:

https://dl.dropboxusercontent.com/u/1293973/Bad%20Surface%20Power%20Supplies%20Cause%20Thumbnail%20Previews%20to%20Disappear.docx

If you have this bug, please post the serial number of your power supply to the thread below, so that we can include it in the above document for Microsoft.

Also, take your old power supply to a Microsoft Store, give them the above document, and demand a replacement.

Note that we're not certain yet if some subset of power supplies being manufactured today by Microsoft is still bad.

For follow-up, I recommend posting to this larger, very active thread:

https://answers.microsoft.com/en-us/windows/forum/windows\_10-desktop/windows-10-taskbar-thumbnails-preview-keep/c74dfbe8-db09-4d5f-b7a2-f7a2f0fc7da4?page=19

Thanks,

Steve

Yes, same behavior on SP4, issue occurs if (1) powered in dock or (2) powered directly with power cord. 

Unplug or remove from dock and issue disappears. 

Why is this so difficult for Microsoft to resolve?  It's been going on for so long now. 

Bill