Well, I got the chip today and successfully soldered it on, no shorts anymore.
Knocked a few caps and resistors out the way and spent an ungodly amount of time (hours) putting them back. But they're back.
And now when I plug in the charger it gives me steady 5v, as opposed to the bouncing 1V-2V it used to give.
I read on another post on this site that it might be because the PD controller can't talk to the EEPROM to get its firmware. Maybe cause the EEPROM is corrupted :/
But I also remember watching a similar repair video where the slavic brit...
atlas667
Trying 2 fix it
Last Activity: 07-03-2026, 12:36 PM
Joined: 06-10-2026
Location: Louisiana
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I've decided against injecting voltage into the CPU, I've since read that CPU's have low resistance, so it may be totally fine. Nothing on the rail has ridiculously low resistance, so I feel its good. Just 15-20Ohms.
I ordered the TPS65994ADRSLR once it gets here I'll put it on and probe the previously shorted locations just to confirm.Leave a comment:
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It ain't over till it's over.
I'm gonna see if I order a cheap-o power supply and inject power into CPU rail to check if any of the caps heat up with rosin smoke or alcohol.
I guess spending 50 bucks on a power supply and checking to see if its fixable is worth it. 😓
Power supply will probably get here in 2-3 days. I'll be back if any updates occur in the meantime.
These are some of the pics of what the board looks like right now....Leave a comment:
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I've pulled all the inductors off the CPU power rail and I'm still getting shorted CPU bypass capacitors
Is this a sign of a shorted CPU or is there still a chance its BadCaps (TM)?😓
Any suggestions?Leave a comment:
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I've been reading on "distance to fault" to see if I can find any shorted capacitor, but the lowest reading I get is 17.6Ohms across a few bypass capacitors on the CPU.
I'm going to remove all the inductors again to see if that helps.Leave a comment:
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I removed the PD Controller (TPS65994AD) and it DID remove the shorts on the input side.
So all these shorts in the picture i took of my board and drew in red are resolved when the PD controller is not present. Yes, that chip IS the PD controller. (Some of those pins marked are ground, the rest of the shorts were resolved)
But the CPU side is still shorted.
I removed all the inductors in an attempt to isolate the CPU side, and still, all the CPU capacitors came up as shorted.🤔Leave a comment:
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I've also just realized that there are 3 inductors leading to the CPU and they are connected, so my theory of removing the one inductor (PL8401) would only help rule out if that one mosfet chip feeding it is good/bad.Leave a comment:
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Hey, thanks for taking the time.
Resistance on the last inductor to the CPU is exactly 15.8Ohms. But when i switch probes it reads 19.9Ohms. Maybe it's my cheap-o meter.
I don't have a variable power supply right now, so I can't inject power, unless I do some sketchy stuff with some batteries. 🤔
Thanks for the alcohol mention, I've been looking for 99% alcohol everywhere. Going to Costco tomorrow.
I've been waiting to make time and remove the PD controller and inductor to check where the short lies....Leave a comment:
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I'm gonna try 2 things to isolate the shorts.
One is remove the TPS65994AD to see if it eliminates shorts on the input side.
The other is remove the last inductor (PL8401) to the CPU to check if the CPU side is shorted....Leave a comment:
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I keep tracing this short around, I am at a loss. Now I found shorted components near the CPU inductors.
15V rail seems to be fine tho.
Hopefully its a single shorted component, but IDK. This close to the CPU makes me worried. Don't know what else to think....Leave a comment:
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Well, I got a little desperate and did it already.
I pulled them all out one by one and tested the other capacitors and they were all still shorted.
This makes me suspect its the TPS65994ADRSLR.
Although now that I'm thinking about this, If capacitors on input and output sides of the chip were shorted, my test would not work. I may try this again by removing multiples...
Anyone have any other thoughts or leads I can explore?Leave a comment:
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I tested the board with the rosin atomizer, but it showed nothing in the suspected problem area with all the shorts. Smoked some other areas, near mosfets, but nothing seemed to show up.
I think it's cause the voltage that is being negotiated by the charger is too low (1V-2V) so nothing is gonna heat up.
Tomorrow I'm going to remove the suspected offending capacitors shown in red circles in the previous post one by one and see if any of them is bad and it eliminates the short.
I got some tweezers, a USB-C soldering iron and OK eye sight, wish me luck.Leave a comment:
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The line VINT20_IN does not have a short, which leads me to think that it is likely no other component connected to it is shorted.
My suspicions are now that it could just be the capacitors circled in red in my last post that are dead. Because if it was the TPS65994ADRSLR then many other pins would be grounded since the bottom of the chip is all ground plane thermal pad.
I'm gonna get the rosin smoke maker soon, and see what happens, if it only lights up these same spots, then I'm going to replace these capacitors in the next week to see if it fixes anything....Leave a comment:
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HQ Schematic images:
Also I might add that I am seriously suspecting a USB-C docking station with charging delivery to be the culprit in this. Though I have no real way of confirming this. But I actually have 2 dead laptops with similar symptoms, I thought the first one was a fluke, but this happening twice has me thinking........Leave a comment:
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I see the schematics images are illegible, I will attach higher quality versions tonight when I get back from work.Leave a comment:
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Lenovo X13 Yoga Gen 2 | 0V battery, wont charge, wont turn on
Hey, all
I have a very general understanding of electronics and do simple repairs, but I'm still very much a layman. Here's my progress so far.
Device: Lenovo X13 Yoga Gen 2
Motherboard: LLX-1 203015-1
Symptoms:- Turned off suddenly.
- Won't power on.
- No charging light when USB-C plugged in.
- No power on with just USB-C.
- USB-C voltage bounces around 1V to 2V
- Battery measures 0V.
- CMOS battery read 2.4V (3V nominal, and I replaced it cause it was cheap and quick, didn't work)
The 0V battery immediately jumped at me as a... -
Hey all,
Glad to be here.
I've always tinkered around with electronics, but now that I can afford to get more tools I have to gain more knowledge.
I'm a noob, really, but love to fix things.
IMO right to repair can only exist meaningfully and permanently if consumers/workers can control production in their favor. Else it will be a permanent cat and mouse game that corporations have nearly full leverage over. Sometimes the cat catches the mouse.
Will be posting soon about a problem I'm having. Have 2 dead laptops, and it might be the same issue....Leave a comment:
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