11-05-2018 11:15 PM
I was using my Yoga 910 and it just went dead. No lights, will not power up. Tried holding down power button and no help. Also have tried other known good AC adapter.
Thank you for any suggestions...
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11-06-2018 05:12 AM
Do you see any lights next to the USB-C charging port (the rear one) when you've plugged either charger into it?
Have you tried starting it with the NOVO button?
11-06-2018 11:31 AM
11-06-2018 01:29 PM
If you're seeing no lights by the USB-C ports and pressing the NOVO button (just a press, not a hold-down) does nothing, then it's most likely time to send it in. You've already tried different chargers from the rear port and, I'd imagine, different outlets. And if pressing power doesn't even get Caps Lock to blink, then you're out of options. The fact it just quit on you - no low battery warning or anything - doesn't bode well.
I wish you well.
11-06-2018 07:35 PM
11-07-2018 06:29 AM
I can measure 5 VDC near the USB power port, but difficult to tell much more.
I'm not sure what you mean. What test did you do?
11-07-2018 04:35 PM - edited 11-07-2018 04:39 PM
Under the bottom case cover there is a small circuit board that has the USB-C power port and the other USB port mounted to it. There is a small solder joint on it. I’m not in front of it now, but think it said JP7.
With a DC voltmeter, I measured 4.97 volts between the solder joint and the screen hinge, which I assumed was grounded. If I disconnect the AC adapter, that voltage goes to zero.
From that small circuit board, there is a ribbon cable connecting it to the main board. I didn’t find any voltage to measure on the main board, but assume the power goes through that ribbon cable. Without a schematic I can’t tell where the problem might be.
I looked up the motherboard cost and appears it may be close to $1000 so not very encouraging. It has 16MB memory and a 4K display so I’d love to salvage it but the cost appears pretty high.
11-08-2018 06:23 AM
Without disassembling my own or digging up a schematic, I'm not sure what that point is.. I will say that the AC chargers should be delivering 20v, not 5v. These ARE OEM chargers, right?
You could just be measuring the part of the power board that supplies 5v elsewhere to the computer, including the USB port on the opposite side. Bottom line, I'm not sure that measurement rules out anything. Could be the USB/Power daughterboard fried, could be the motherboard. Going on the fact you received no warning before it just quit (Windows usually tells you when you hit low battery conditions) still has me suspecting the motherboard.
11-08-2018 09:47 PM - edited 11-08-2018 09:59 PM
No, unfortunately these are 2 non-OEM chargers. They have been working for about a year, after I broke the OEM charger. But, trying an OEM charger is probably worthwhile.
They indicate they can provide between 5 and 20 volts.
On the pic, I measured the 5 volts between PJ7 (to the left of the USB plug) and the hinge behind it. I’ll look around and see if I can find a published schematic.
Your guess at the motherboard makes the most sense... Just not what I was hoping to hear
11-09-2018 05:08 AM
The 910 is fussy when it comes to non-OEM chargers. I had to go through a few before landing on one that worked. I bought a slim one to use on planes, but it won't charge the 910 when its on and only slowly when the 910 is off. The same charger works as it should with my 920. The HP charger, while a little bulky for my travel bag, works fine on either machine. And I have the two Lenovo bricks that came with the computers.
Still, no warning and no lights leads me to suspect the worst, but trying an OEM charger certainly couldn't hurt. And it's not as if a new charger won't come in handy for other devices at some point..