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

Steve,

You probably noticed they removed your eMail from the post, and also from my notification. So replying here... 

Apologies if the typeface comes out weird. In Firefox, I can't use "Format" at all. If I switch to Chrome, and try to make the diagram a code block, it insists on changing the entire message. Oh, well...

The 15 Volt adapter is generally much better than any source of 12 volts. Maybe with the lower power draw of the SP4, it is a sufficient improvement. I have the i7 Surface Book with the graphics chip, and under many operating conditions 15 Volts almost hides the problem. But as I said, when I'm on the edge of a battery state transition, like _almost_ fully charged, the state chatters back and forth with CPU loading, and every time the state changes, the previews drop.

The data I think you need to gather from people who see the problem is what state their battery is reporting - or rather which states it is chattering between. And also what the report is when the problem is least apparent. For me, the worst case chatters between "in use" and "fully charged", and since the SB has two batteries, it also chatters between one or the other "in use". If both are severely discharged, it can often stay on "charging" for both of them for longer periods.

In my first post, I said the top line changes to "Not charging", one of the batteries changes to "in use", and then the top line says "Calculating", and then finally they all agree both batteries are charging. I don't notice that any more - I believe one of the major updates removed the "Not charging" and "Calculating" reports. But the state changes still chatter as often, I just see fewer messages.

As for your third-party adapter being an improvement, I see a couple of possibilities. It might put out more than the nominal 12 volts, or less - as might your original MS adapter. Down around 12.2 Volts, my system chatters its worst between "charging" and "fully charged". A bit less and it gives up charging, a bit more and it can hold onto "fully charged" longer. I don't have an OEM 12 Volt adapter to try.

Another possibility is that Microsoft does something tricky with those other contacts on the power plug, and the third-party adapter does not. I was not able to measure anything going on when the plug is not connected to my computer, and obviously can't reach the contacts when it is. I know my pure DC connection just provides the DC on the main pairs of pins.

Here's what I know:

After  Orig    ________    Orig  After

              |        |              

              |        |              

centr  5-10V  |  o||o  |  5-10V  centr

centr  0V     |  o||o  |  0V     N/C  

outer  0V     |  o||o  |  0V     outer

              |   ||   |              

              |   ||   |              

              |   ||   |              

outer  0V     |  o||o  |  0V     outer

N/C    -.03V  |  o||o  |  0V     centr

centr  5-10V  |  o||o  |  5-10V  centr

              |        |              

              |__    __|              

                 |  |                 

                 |  |                 

                 |  |                 

"Orig"inal measurements are voltage relative to the USB -/neutral pin on the charger. (Fluke 87 ohms scale found no connection between USB -/neutral and any fin contact.) Recorded values are from the DC Volt scale with the charger powered. "5-10V" values were recorded (100ms min/max) as minimum 4.5V, maximum 10.2V, with a constant rapid pulsation. The single "-0.03V" reading was solidly repeatable and not present on the opposite mirror image pin. All other pins were below 10 mV. Apparently the power supply is in some kind of seek mode...  

"After"market measurements are Ohms scale connectivity between fin contacts and the center socket or outer sleeve of the 2.1 x 5.5 mm DC plug.

I do know the LED in the Microsoft plug only comes on when the plug is in the computer, so they are sensing things and changing the output in response. The LED in my aftermarket cable is on all the time.

I'm curious what tool or program you're using to see the PBT_APMPOWERSTATUSCHANGE messages. But my view is that they are going to happen regardless of the power supply, and Microsoft just needs to make the taskbar previews ignore them. I can't imagine any reason they should be connected. 

I'm happy to test things on my Surface Book, if the procedure isn't too time consuming...  

Loren

Loren,

Here's one more bit of data.

The Kingdo power adapter's output is:

12 V @ 2.58 A = 30.96 W for the Surface, and

5 V @ 1 A = 5W for the USB plug.

Overall, it produces just under 36 W of power.

I believe that these specs are identical to the ones for the original SP4 adapter, which I no longer have. Perhaps someone else can confirm this.

So, I'm using 12 V on my SP4 right now--the same SP4 that produced #ThumbnailPreviewsDisappear nonstop using Microsoft's original 36 W adapter. And I'm experiencing zero #ThumbnailPreviewsDisappear using this Kingdo 36 W adapter.

Even though I'm only one data point, if my results generalize, then there's no difference between 12 V as opposed to 15 V on #ThumbnailPreviewsDisappear.

Thanks,

Steve

Hi Chris,

I'm very happy that it worked for you, but it's possible that that power supply is just masking the real problem. We don't know yet. It's also possible that if you got another 65W power supply, it *wouldn't* work. At the very least, that swapping power supplies has worked for some of us once again shows that this is some type of power management bug--and possibly a very complicated one.

Could you please post the model number, status (good/defective, where defective=#ThumbnailPreviewsDisappear), and serial number of your various power adapters, and the model of the Surface device(s) that you're using these adapters on? We need as much data as we can get to force Microsoft to get to the bottom of this.

At this point, swapping power supplies is a possible solution, but I worry that we haven't heard the last word on this bug yet.

Thanks,

Steve

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