Lenovo Ideapad 320-15ikb: Comes on and goes off

[mcplslg123]

PL401 is +3VALW line and its dead short to GND now.This is bad news.
Very likely PCH part of SOC is shorted(smaller die) as well as SIO.
It seems your multimeter probes are not needle sharp and you accidentally touched 2 different rails while measuring.

[Nagyesz]

Yea I actually managed to short something
Pl401 went from 21.3kohm to 0.04ohm 😶

[Nagyesz]

@U13
pin 1 5.1V then 0
pin 2 5.1V then 0
pin 3 5.1V then 0
pin 4 5.1v then 0
pin 5 5.1V then 0
pin 6 5.1V then 0
pin 7 5.1V then 0
pin 8 5V then 0
pin 9 5V then 0
pin 10 10.16V then 0
pin 11 0v
pin 12 5.1 V then 0
pin 13 5.1V then 0
14 5.1v then 0v

I might have done something wrong because UL1 is getting very hot, and you can feel the processor heating, when it's turned on

[Nagyesz]

As soon as I have a minute, I will measure it. Thank you!

[mcplslg123]

Going by your reading at QC2,3VS is missing.
Measure voltage on pin1-2/6-7/8-9/13-14 of U13(after pressing power button).

[Nagyesz]

@QC2
On cable:
pin 3 3.36V
pin 2 0V
pin 1 0V
pin 4 0V
pin 5 0V
pin 6 3.36V


After pressing power button:

pin 3 3.36V for few secs then 0V then 3.36V
pin 2 stays 0V
pin 1 stays 0V
pin 4 stays 0V
pin 5 stay 0V
pin 6 for few secs then 0V then 3.36V


@UC4:
on cable
only pin4 has 5.1V

after pressing power button
pin4 has 5.1V for few secs then 0V and then 5.1V

@Pl202 and Pl201
On cable 8.4V both
After pressing powerbutton
8.4V drop to 0.21V and (!) stays there I need to replug the power to get them back to 8.4V

[mcplslg123]

The motherboard is on your table and continuity check only you can do. We've guided you to the rpobable fault area. You need to look carefully to find something.
Read the diagram a bit and you can easily figure out that pin1-2/6-7/8-9/13-14 are in continuity-so why waste your time measuring that way. Simply meaningless.
What is the voltage on pin1-2/6-7/8-9/13-14 of UC4 after pressing power button?

[Nagyesz]

Sorry, I worded it poorly. I measured in diode mode just as you said, and I also measured the voltage correctly I think.

But I think there is an error, and that is with TB-TP486

[mon2]

Wait..if you are checking the voltage to ground of any component, the meter must be in DC Volts mode (not DIODE mode). No beeping will occur in DC Volts mode. In this mode, the BLACK meter lead will be to ground and the RED meter lead to the part to test. You are measuring the voltage potential to ground.

Only if you are wanting to test in DIODE mode, then use the DIODE mode scale with red meter probe to ground and black meter probe on the component to test.

Each test method has its benefits but be sure that in DIODE mode or RESISTANCE mode, there is no power to the logic board. This is important.

[Nagyesz]

I did it exactly the same way, the recorded values are up. I measured the Volt by plugging it into the charger.

[mon2]

If you are testing in DIODE mode -> be sure there is no power to the board.

Red meter probe (yes RED) to ground and BLACK meter probe to the point to test. Then record the measurement and post your values.

[Nagyesz]

@UC4 in Diode Mode

1-2 6-7 pin is beeping with eachother (+1.0VALW)
pin 4 beeping with @ UC2 pin 5 (+5VALW)
pin 14 and 13 beeping with eachother (+VCCIO)
pin 14, pin 13 beeping with @C1102 and @cc1250 1 pin
pin 12 beeping with @CC1293 (N25889877)
pin 12 beeping with N25889877 (trace?)
pin 11 gnd is ok
pin 10 beeping with @CC1292 pin 1 (N25889881)
pin 9-8 beeping with eachother, beeping with @CC86 pin1 and @RC1604 pin 1 and @RC105 pin 1

@QC2 in Diode Mode

pin 6 beeping with @RPC20 pin2 and PCH_SMB_CLK
pin 5-2 beeping with eachother and @QC10 pin 2-5 and @U1 pin 1
pin 3 beeping with @RPC20 pin1 and beeping with PCH_SMB_DATA

!!!
@QC2 pin 2 is beeping with this


@RPC25 pin 2 and @QC10 pin 3 (PCH_SML1_DAT) doesn't peep with TB-TP486 (look attached) I tried everything and not a single beep




Edit: @RPC25 has 3.3V and TB-TP486 has 0.5V-0.6V somehow

[Nagyesz]

Thank you very much for the response. But as I mentioned, I'm not that good with the meter, so if you could tell me which mode and how to start, I'd appreciate it.

After the cleaning it still behaves the same way. Goes on for few seconds then off and red blink

[mcplslg123]

My gut feeling tells me that your problem lies near UC4/QC2 area. Check each and evry track with your multimeter.
Btw, what is the change after cleaning this area?

[Nagyesz]

It's been wiped out with alcohol again, the situation has changed a bit, but unfortunately it still behaves the same way at startup.

[Nagyesz]

I've been thinking about this too, that might be the issue. I'll check it soon. Could you possibly tell me what mode to use the meter and what exactly I should measure?

[SMDFlea]

Thank you, I really overlooked it. However, could this mean something?

Pin 4 is ok 5 volts Always on voltage. Pin 10 looks like it might be bridged or it has something on the solder. QC2 might have a broken trace

[Nagyesz]

Thank you, I really overlooked it. However, could this mean something?

[SMDFlea]

I measured it, and I find it a bit odd that I only measured 5.1 volts on the 11th leg. ( power cable is only plugged)

What youve measured is pin 4 ,look at the number 1 (and the white line next to it) and 8 around the IC .

[Nagyesz]

I measured it, and I find it a bit odd that I only measured 5.1 volts on the 11th leg. ( power cable is only plugged)