Yoga C740 Not Charging

[Appletax]

Yoga C740-15IML​

Started out at 100% battery. Says it's charging, but the battery keeps depleting. Charges via USB-C. Can use either port to charge it.

Now it's charging. Not sure what to make of it. I can't test the AC adapter with a multimeter. Looks like I should purchase a USB-C testing unit. Any recommendations?

Lenovo Diag reports no issues with the battery.

HWiNFO shows a 4.7% wear level on the battery and 55 cycle counts.

 

[nlinecomputers]

I don’t understand the issue. Is it charging or not? Slow charging? Intermittent Charging? Have you tried another charger?

 

[fincoder]

Started out at 100% battery. Says it's charging, but the battery keeps depleting.

Down to what level? Many laptops will manage the charge level automatically, letting the charge level drop to a certain level (e.g. 95%) before recharging, to help maximise battery health.

Looks like I should purchase a USB-C testing unit. Any recommendations?

It's called a spare USB-C charger. They're all compatible, doesn't matter what brand, as long as it puts out enough watts (usually 65W).

I have lots in stock, one on the workbench, they work with lots of modern laptops including Macbooks. From my distributors I find the Dell 65W USB-C chargers are cheaper than anything else including generic. No reason not to have at least one for testing.

 

[frase]

You can also get the Universal Chargers that have the USB-C included amongst others. I use them for testing purposes.

 

[gadgetfixup]

You need one of these so you can tell what is going on. What voltage and what amperage between charger and laptop. Without knowing V and A you're just guessing. Mac and Nintendo switches communicate at 5v and after successful checks boost to 15v - 20v. Knowing if you're boosting correctly or sitting at 5v is the first step in the diagnosis.

Yoga's are notorious for bad ports and bad USB-C controller chips.

https://www.amazon.com/Testers-KJ-KayJI-Multimeter-Capacity-Temperature/dp/B07X3HST7V/

 

[Appletax]

I don’t understand the issue. Is it charging or not? Slow charging? Intermittent Charging? Have you tried another charger?

It was not charging at all. Now it's fluctuating between 95% and 100%. I sure hope it stays working.

You need one of these so you can tell what is going on. What voltage and what amperage between charger and laptop. Without knowing V and A you're just guessing. Mac and Nintendo switches communicate at 5v and after successful checks boost to 15v - 20v. Knowing if you're boosting correctly or sitting at 5v is the first step in the diagnosis.

Yoga's are notorious for bad ports and bad USB-C controller chips.

https://www.amazon.com/Testers-KJ-KayJI-Multimeter-Capacity-Temperature/dp/B07X3HST7V/

Thank you for the link to the tester. I ordered it.

Sucks to learn that Yoga's are notorious for those issues. This laptop is quite nice - made of metal, backlit keyboard, nice display, etc.

I just dealt with a Lenovo with bag hinges (back cover's screw holes are super shallow and fragile). Not good, Lenovo.

 

[nlinecomputers]

The only good Lenovo is the Thinkpad line. They are awesome. The various retail lines tend to be junk. Not seen a legion so I can’t comment on it.