Lenovo E540 no 3/5valw

[techyhomer]

Hi all,
I have an aile2 nm-a161 rev 1.0 board that IO ITE8586 and 3/5v regulator was defective so I Have replaced the IO with a new programmed one, but when I replaced the regulator I did not get the 3/5v on the inductors
and here are the readings from the IC:
1 FB1 0
2 ENTRIP1 0,9
3 TON 2
4 ENTRIP2 1,5
5 FB2 0
6 PGOOD 0
7 BOOT2 4,5
10 LGATE2 0
9 PHASE2 0
8 UGATE2 0
11 VIN 20
12 ENLDO 3,2
13 ENM 1,3
14 LDO5 5
15 LDO3 3,3
16 LGATE1 0
17 PHASE1 0
18 UGATE1 0
19 BOOT1 4,5
20 BYP1 0

All the components around the IC are good, as far as I have checked. Can you guys help me discover the problem?

Schematic ---> https://www.badcaps.net/forum/showthread.php?t=88932

[mon2]

Re: Lenovo E540 no 3/5valw

These rails are powered by the B+ rail which is present only after the 2*DCin mosfets are enabled.

For this reason, check the voltage to ground of the 2*DCin mosfets. Interested in the source / gate / drain pin voltages to ground (pq301 / pq304).

[Vesko356]

Re: Lenovo E540 no 3/5valw

Hi all,
I have an aile2 nm-a161 rev 1.0 board...

Do not attach laptop schematic and/or BV in this section please!

Schematic Requests ONLY!
https://www.badcaps.net/forum/forumdisplay.php?f=41

Reminder: rules and organization of this section
https://www.badcaps.net/forum/showthread.php?t=117483

If you request/offer BIOS/schematics/boardviews, please post in the appropriate subsection, and you can link to it in the troubleshooting topic.

.

[techyhomer]

Re: Lenovo E540 no 3/5valw

Hi, I have measured all the mosfets before. pq301 / pq302 only the B+ is present on pin 5. For pq303 pq304 no voltage at all.

[Udemzy]

Re: Lenovo E540 no 3/5valw

Since entrip is available, replace the polarized capacitors but your Pin 13 is 1.3v which is wrong.

[techyhomer]

Re: Lenovo E540 no 3/5valw

According to the data sheet of RT8243A having 1.2V to 1.8V on Pin 13 will activate the switching mode on ASM==Audio Skipping Mode==Ultrasonic Mode. For the polarized capacitors I have checked and the they have no short. I wonder if I can run the IC without the caps to see for seconds if their is any voltage on conductors, since I cannot get hold of new caps right now.

[techyhomer]

Re: Lenovo E540 no 3/5valw

I have replaced the RT8243A with a used one, but the readings I got was very faulty even it did not have any short. I went back to the original RT8243A, but I want you guys to confirm if it is safe to run the IC without the caps? since I have removed the jumpers PJ402 PJ403.
For the pin 13 ENM what is the ideal voltage, should it be 3.3v?
I was planning to remove PR420 and connect ENM with LDO5 to see if the IC is faulty or not. is it a good idea?
Pressing the power btn does not lead to any change though 3vl is present.
On PD401 pin1 I have 2.7 volt but on pin2 I have 1.3v!

[techyhomer]

Re: Lenovo E540 no 3/5valw

I have replaced the RT8243A IC twice but every time I get PQ401 and PQ403 mosfets shorted and burned. The IC has no voltage on outputs or very low voltage though VIN 19.5 and ENLDO 3,2 are present.