Lenovo Yoga 7 laptop - flashes the white power led three times quickly

[Blue House Computer Help]

I have a Lenovo Yoga 7 laptop (recent model) that won't start up at all. It just fires up the fans and keyboard backlight, and flashes the white power led three times quickly. Then it shuts of and does it again on loop. Nothing on screen even when hooking up an external monitor to the hdmi port.

Could it be that the power button is stuck pressed down? It's one of those weird side mounted power button that Lenovo do for their yoga's, but it doesn't feel like it has any play when I press in it. I opened the laptop up to have a look, but it would take a lot of tearing down to find out, and they just wanted basic analysis so far.

I tried it with the SSD removed (power light flashes 3 times quickly then 3 times slowly) , and the ram is soldered in, but it didn't do anything more.

Ring a bell? Or any other thoughts?

 

[gadgetfixup]

Smash down on the ram chips while turning it on.

 

[carmen617]

Did you try draining flea power by disconnecting the battery, holding the power button down for 30 seconds, then reconnecting the battery?

 

[Blue House Computer Help]

@carmen617 Yes.

@gadgetfixup Really? Are you pulling my leg?
Can you elaborate? Why might that work?

Anyone else... What would you do? I'm thinking about changing out the power button, And I noticed that it seems that 2 of the corners, including the one with the power switch on, are a tiny bit buckled, like it's been dropped. I wouldn't even bother about it except it's quite an expensive and not very old laptop.

Just so you have a visual in mind, here it is. That oval button just behind the two usb ports is the power button.

Has anyone laid hands on one like this? I'm feeling like zero movement when I press the power button, and I feel like I should feel some, and that that means something is dented in there.

 

[fincoder]

Has anyone laid hands on one like this? I'm feeling like zero movement when I press the power button, and I feel like I should feel some, and that that means something is dented in there.

Time to open it up. You should be able to bypass the power button by shorting its contacts. See if it comes on that way to confirm it's the power button.

 

[NviGate Systems]

English Community-Lenovo Community

Interesting another user posted about the battery LED flashing, and I'm not sure how many LED's there are, as perhaps it's not that, but it could be a low battery warning and the unit can't get enough current to start?

There also cases where the battery management crashes (BIOS Level) and disconnecting battery is the only way to fix it. Some laptops have a pinhole underneath to do this, you put a paperclip in for like 20 seconds and then try again.

I'm not sure but I recall that some laptops these days including Lenovo would not power on if the battery was bad or low/removed. So it's possible it's a battery issue, as in that post above the Lenovo Rep said those flashes were part of the inbuilt management system, and sadly Lenovo doesn't seem to document them. Also, on reddit's r/Lenovo sub, I've seen Lenovo Reps helping users with identifying issues and giving them service steps to try and fix things, might be worthwhile to post there, one of the reps might be able to tell you what 3 flashes mean. I'd start there before ripping it apart.

 

[carmen617]

You haven't mentioned, but have you tried a different charger?

 

[gadgetfixup]

@gadgetfixup Really? Are you pulling my leg?
Can you elaborate? Why might that work?

A power button that doesn't click is suspect.

I wasn't really pulling your leg. So with soldered-on RAM, on newer laptops when the keyboard or laptop flexes, it can crack the brittle solder balls that hold the ram to the mainboard. When you press down on the ram chips you make the connection, and it will boot as long as you have pressure on the chips. It's also a method for determining which ram chip to reball when ram is suspect. Sorin at ERS has several videos showing this method, and I've used it for years when ram is soldered on. It doesn't always work but it's quick and easy enough to do.

If you can't turn it on or interrupt its power on test with the power button I'd look there first. You should feel it click.

Not sure if you have a benchtop power supply but highly recommend one for jobs like this. You purchase a cheap universal charger with a ton of tips for different laptops. Cut the cheap charger off the cord and connect it to a benchtop power supply. Plugging in a laptop to a power supply will give you a ton of information about what is going on. We would be lost without our bench power supply giving us amperage readings during post. We often know what is going on without removing the bottom cover.

A corrupt BIOS is also on the list of suspects. BIOS communicates with EC (SIO) chip on boot, if the data is corrupt, the BIOS sends the corrupt data to the EC and EC doesn't know what to do with it, board reboots. A ton of possibilities really. Many modern laptops have 2 or 3 BIOS chips and the board is dependent on all of them working.

 

[TechLady]

There may be a soft reset hole on the bottom...look for that. If there is one, it can fix many a strange issue, including this stuff.

 

[Rigo]

benchtop power supply

Care to share a little more about this?
Thanks

 

[Mick]

Will it boot from a PE disk (or equivalent)?

 

[frase]

Board level error, I think it's dead Jim. I have had these issues before with these systems, you may need to dissassemble just to make sure that no connectors are displaced or board damage as you stated it had been dropped.

 

[GTP]

Ahhh the OP was from Nov 2023, so I think its either fixed, dead, or sitting on a shelf perhaps....

 

[Markverhyden]

Ahhh the OP was from Nov 2023, so I think its either fixed, dead, or sitting on a shelf perhaps....

If he had a second one he could sell them as a set of not very high tech book ends.........

 

[britechguy]

Ahhh the OP was from Nov 2023, so I think its either fixed, dead, or sitting on a shelf perhaps....

And, like all things in the world of computing, even the move from legitimate follow-up to necropost occurs at a greatly accelerated speed!

A year is a hundred lifetimes when it comes to any given repair, in particular. It's done, or dead.

 

[Blue House Computer Help]

To answer @Rigo's question and put this post well and truly to rest, I think when @gadgetfixup was talking about a benchtop power supply, he might have been talking about one of these universal chargers with multiple tips for lots of different laptops. I found mine on Amazon just by searching "universal laptop charger".

And surprisingly, the motherboard wasn't dead. The power button had come out of contact with the tiny switch on the circuit board. I fiddled with it to try to get it back into position but eventually had to replace the palm rest and then it worked.

 

[Larry Sabo]

I think when @gadgetfixup was talking about a benchtop power supply, he might have been talking about one of these universal chargers with multiple tips for lots of different laptops.

I think @gadgetfixup was talking about a bench power supply, like this, to which he would have connected tips that match the laptop under test/repair. One normally buys a universal charger with multiple tips and uses just the cable from it to connect to the bench supply.

 

[gadgetfixup]

Get a benchtop power supply capable of delivering 5A or 10A at 19V—most benchtop power supplies can meet this requirement. Then, take a universal charger, cut the cord, and connect the red and black leads to your power supply.

The purpose of this setup is to measure the current draw, which can provide valuable diagnostic information. Just as you might do when troubleshooting phones, tablets, or even game consoles, analyzing the current draw helps you understand what’s happening when a device is plugged in or when you press the power button. A device might seem dead, but the current draw could indicate it’s still functioning in some way. By using this method consistently, you'll develop an intuitive sense of what’s going on with a laptop even before removing its cover.

We used this product to build our leads because it uses a barrel plug to swap out adapters. You can find about 30 different adapters that work with this barrel plug to cover practically every brand laptop out there.

https://www.amazon.com/SHNITPWR-Adjustable-Universal-100V-240V-3-5x1-35mm/dp/B08BL4QMGM/

 

[HCHTech]

I think @gadgetfixup was talking about a bench power supply, like this, to which he would have connected tips that match the laptop under test/repair.

I almost ordered one of those a few years ago for this purpose, but i stopped short because it wasn't clear to me how to handle the different wattages expected combined with the variable polarity. I didn't want to make it easy for us to fry a customer's laptop because we guessed wrong when the customer didn't provide the OEM charger when they dropped it off. More units are going USB-C these days, but we still see the rectangular Lenovo connector quite a bit. We have a drawer full of aftermarket chargers so usually we just fish through there until we find the right one.

However it's year end now and we have some money to burn, maybe I should pull the trigger. Do you still find this setup covers all of today's options? How to you check for the requirement of reverse polarity when you don't have the OEM charger?

 

[Larry Sabo]

@HCHTech, I bought a HANMATEK HM305P PSU (which I can no longer find for sale?) and this kit of 38 laptop adapters. It's rare that I don't have a required adapter and the set-up works very well. I have a salvaged cord that has the plug that fits into the 38 adapters and whose leads connects to the terminals on the PSU, plus a probe+ground clamp also connected to the terminals to use for voltage injection. I have never encountered a laptop that doesn't have the centre pin positive; I don't think one exists.

Having this set-up or one like it is very helpful but the essential thing is to understand electronics and laptop circuits in particular, so you know what to test and how to interpret results. There are many really helpful channels on YouTube to help with that. Sorin's Electronic Repair School is probably one of the best.

Edit to add: some laptops require communication with the charger to validate the charger and won't run or charge if the OEM charger is not detected. In such cases, the set-up mentioned is useless because the EC chip won't allow the laptop to run. You can still inject voltages and look for shorted components if the problem is a shorted power rail but having the original charger is still sometimes required so don't throw out that collection!