[SOLVED] Lenovo Y700 won't boot

Apr 27, 2020
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A few days ago, my laptop has become unresponsive. Last it was powered on, it cycled to sleep mode successfully, and was still providing power for a device via USB before I attempted to start it again.

Upon pulling up the screen and hitting the power button, I had no response from the system. Nothing on screen, no sounds of fans or the HDD installed, and no indicator lights.

Plugging it in, I get no response from the battery indicator light, and the same lack of response trying to boot it.

Model is a Lenovo IdeaPad Y700-15ISK, 80NV. Way out of warranty so I have no qualms opening it up.

Bought a new charger as the slim port on the adapter is a little hard to get a read with a multimeter, no effect.

Have attempted to flush any excess static with the battery in, and with it removed, to no effect. Trying to start the machine with the battery removed gives no response either.

I have a multimeter handy, and a couple of good screwdrivers. What's my next step? Thanks y'all.
 

lga1156_ftw

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Feb 25, 2020
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It is this model right?
View: https://www.youtube.com/watch?v=Q0t2GwAha-s


If dc jack cable is fine then remove battery completely and power cable also then start removing connectors from the motherboard (just with your hands) do not use any force, the connectors have small plastic clips and different mechanisms. Just watch disassembly videos if you need help with them.

I would first remove these:
-HDD , pcie SSD (these might differ depending on model but remove all)
  • cmos battery
  • speaker connector
  • that usb motherboard extension near the dc jack cable (just remove from the usb /audio hub side)
  • wifi card
  • LCD cable (look near hinge on the left in that disassembly video)
Check that the connectors are fully removed from the motherboard and not only partially causing short, then plugin power cable and it should boot right away without cmos battery inserted if some of these parts is causing it to not work.

If it doesnt then remove power cable and again until you disconnected Everything you can without removing motherboard and repeat (even power button cable can be disconnected at this point since cmos battery is removed)

EDIT : just saw geofelt comment this can be tested when removing cmos battery it will boot straight awawy without pressing power button when you plugin power cable
 
I had one of those units some time ago; good unit, I liked it.
One of the usb ports is always on for charging purposes.
Can you plug something into that port successfully?
Does it make a difference if it is on battery or plugged in?

I suspect that you have a worn out battery; they do not last forever.
I think there is some circuitry in the battery to control battery vs. plugged in operation.
If you replace the battery, buy a legit lenovo replacement, not something that is supposed to be compatible for cheap.

If you open up the case to poke around, be careful. The screws are tiny. They are easy to lose and if you do not screw them in straight, it is easy to strip the scre holes.
 
Apr 27, 2020
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Yes, actually. The USB closest to the power jack does indeed provide power. This is testing after pulling the battery, CMOS battery, and Ram and reseating all of them. Does this still allude to a battery problem?
 

lga1156_ftw

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Feb 25, 2020
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Whatever you disassembly first remove battery connector and power cable from the motherboard, try to use plastic tools for removing connectors, only metallic necrassary is the screwdriver
  1. remove power cable, and remove battery connector or the entire battery , press power button 30sec. Insert onnly power cable and try to boot
  2. Have you tested DC jack voltage from the other side of cable? Does the numbers fluctuate if you tweak the cable , this is common fault
EDIT: i read your post too fast i see you already did most of these things, test the dc jack though.
 
Yes, actually. The USB closest to the power jack does indeed provide power. This is testing after pulling the battery, CMOS battery, and Ram and reseating all of them. Does this still allude to a battery problem?
No, if you get power to the always on usb port, I do not think the battery is your problem.
Could you have a problem with the switch that powers the laptop on?
 

lga1156_ftw

Respectable
Feb 25, 2020
1,265
146
2,390
176
It is this model right?
View: https://www.youtube.com/watch?v=Q0t2GwAha-s


If dc jack cable is fine then remove battery completely and power cable also then start removing connectors from the motherboard (just with your hands) do not use any force, the connectors have small plastic clips and different mechanisms. Just watch disassembly videos if you need help with them.

I would first remove these:
-HDD , pcie SSD (these might differ depending on model but remove all)
  • cmos battery
  • speaker connector
  • that usb motherboard extension near the dc jack cable (just remove from the usb /audio hub side)
  • wifi card
  • LCD cable (look near hinge on the left in that disassembly video)
Check that the connectors are fully removed from the motherboard and not only partially causing short, then plugin power cable and it should boot right away without cmos battery inserted if some of these parts is causing it to not work.

If it doesnt then remove power cable and again until you disconnected Everything you can without removing motherboard and repeat (even power button cable can be disconnected at this point since cmos battery is removed)

EDIT : just saw geofelt comment this can be tested when removing cmos battery it will boot straight awawy without pressing power button when you plugin power cable
 
Apr 27, 2020
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So a quick update. Thank you all for the suggestions so far!

Removing the CMOS battery, flushing any charge, and plugging in the power adapter still has no response from the system. This does not change whether removing either the main battery, the CMOS battery, or with both disconnected from the system.

I don't believe it's an issue with the power button itself. With CMOS and the power adapter plugged in, I can toggle the power of the USB adapter, charging, and stopping a charge to my phone.

The power adapter has a really thin contact on the inside, making it difficult to get a consistent reading on the multimeter. I can upload a video if you don't believe me haha, but between the new and the old charger, I'm still reading around 18/19 volts, which is what the system is rated for.
 

lga1156_ftw

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Feb 25, 2020
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Most important thing is that battery is removed completely and you only plug in power connector when nothing is touching the motherboard to test in between, then plug it off when you disconnect / connect anything.

You can try to remove all you can first then test, and if you get some life into it start diagnosing it part by part. You should get atleast one indicator light when you plugin the power connector.

For the dc jack you can try measuring the pins where it connects on on the motherboard, just black probe to anything grounded on the board (like outside of a hdmi port or screw whole in mobo) and red on pin at a time, do not short it.

This models it seems very easy to test since all the connectors are on one side.
 
Apr 27, 2020
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Most important thing is that battery is removed completely and you only plug in power connector when nothing is touching the motherboard to test in between, then plug it off when you disconnect / connect anything.

You can try to remove all you can first then test, and if you get some life into it start diagnosing it part by part. You should get atleast one indicator light when you plugin the power connector.
I'm currently getting nothing from indicator lights on the machine with or without battery. Just to clarify, are you saying the indicator lights will come back on when I remove a faulty component even if I don't have the battery connected?
 

lga1156_ftw

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Feb 25, 2020
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I never seen this model myself so hard to say but usually there is atleast 3, when you plugin charger you get either bright colour on it if battery is not connected / charging and then orange color if its charging battery.
Or there is 2 different leds for this.

Then obviously more leds light up when you actually boot the system with power button.
 
Apr 27, 2020
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No, if you get power to the always on usb port, I do not think the battery is your problem.
Could you have a problem with the switch that powers the laptop on?
I'm currently getting power to the always on jack even without the main battery connection. When the CMOS battery is plugged in, the system still won't boot, but I can cycle power to the USB port. Does this still leave us with the possibility of a battery issue preventing booting?
 

lga1156_ftw

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Feb 25, 2020
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Do you mean the usb ports which are on the motherboard or the audio / usb hub which is connected to motherboard via ribbon connector?

I didnt quite understand your question, you should be able to charge devices via the "always on ports" even when the machine is not on and only either battery or power cable is connected. This is in working condition.

About cmos battery, you should be able to power on the laptop with or without it installed. It just gives error when you boot that time is not correct. Where is the power button cable connected, have you figured it out yet since i dont have schematics?
 
The cmos battery is used to preserve bios settings across complete power loss.
By removing the battery and unplugging, removing the cmos battery effectively resets the bios to default.
When you say that the pc does not boot, do you mean not boot to windows or does not boot to bios?
If you press the power button, can you access the bios screen?
 

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