Lenovo E560 (BE560 NM-A561) not powering ON

[classicandy]

Lenovo E560 (BE560 NM-A561) not powering ON

My issue:
When I plug in charger, PL201 gives out 3v.
PL202 doesn't give out any volt (0v) while PU202 gets very hot. I have replaced PU202, it still gets very hot.

I don't have schematics yet, but I've made a request. Any help would be much appreciated. Thanks.

[piernov]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

If PU202 gets hot, you have a short to ground on one of its output. Either the LDO (pin 7) or the buck converter (pin 10).
So measure resistance to ground on both pins.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

If PU202 gets hot, you have a short to ground on one of its output. Either the LDO (pin 7) or the buck converter (pin 10).
So measure resistance to ground on both pins.

Ok.

No short on Pin 7 and Pin 10

[piernov]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Just to confirm, in the attached picture I highlighted pin 7 in red (connects to one side of the ceramic capacitor PC225) and pin 10 in blue (connects to the inductor PL202).
If resistance to ground is at least in the kiloohms range on both pins make sure the chip is soldered correctly.
If the chip has been replaced and there is no short to ground on outputs then there's no reason for it to get very hot.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Just to confirm, in the attached picture I highlighted pin 7 in red (connects to one side of the ceramic capacitor PC225) and pin 10 in blue (connects to the inductor PL202).
If resistance to ground is at least in the kiloohms range on both pins make sure the chip is soldered correctly.
If the chip has been replaced and there is no short to ground on outputs then there's no reason for it to get very hot.

The attached image is very correct.

With my multi-meter set to Buzzer/diode:
pin 7 = 83~84

pin 10 = 560

I'm getting confusing values when i use the ohms section.

At 2k ohms range
pin 7 = 100 (and drops slowly)
pin 10 = Above 2k ohms

At 20k ohms range
pin 7 = 0.92~10.2
pin 10 = Above 20k ohms

At 200k ohms range
pin 7 = 00.2 ohms
pin 10 = 50~51 ohms

What is the best settings to use on my multi-meter to get the actual resistance to ground value?

[piernov]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

If you get 100 ohms on pin 7, that's too low. This means there is a partial short to ground on +5VLP.
According to the schematics, there are only 2 capacitors (PC8 and PC225) and 2 ICs (PU1 and PU202) on +5VLP, so you have to remove them one by one until the resistance goes up to at least a few kiloohms.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

If you get 100 ohms on pin 7, that's too low. This means there is a partial short to ground on +5VLP.
According to the schematics, there are only 2 capacitors (PC8 and PC225) and 2 ICs (PU1 and PU202) on +5VLP, so you have to remove them one by one until the resistance goes up to at least a few kiloohms.

OK. Let me check them now. I will post results immediately. Thanks.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

After removing PU1, At 200k ohms range,

I'm getting 55.5 at pin 7
and 46.5~47.5 at pin 10

[piernov]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Ok, seems like the short to ground is gone.
Now when you connect the AC adapter, PU202 shouldn't get very hot, and the laptop should work…

PU1 is not critical, it's an overtemperature protection. Better replace it, but the laptop will work without it.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

ok. I haven't tested it. Was afraid to test it without replacing it. I will test it now and post result.

Just in case, which common laptop can i get a substitute? I've seen a similar type on a particular Acer laptop before (not sure of the model though)

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Ok, seems like the short to ground is gone.
Now when you connect the AC adapter, PU202 shouldn't get very hot, and the laptop should work…

PU1 is not critical, it's an overtemperature protection. Better replace it, but the laptop will work without it.

You're a Genius. It worked.

Next is to replace PU1. Can you recommend any equivalent for PU1 ic. According to schematic, it is G718TM1U_SOT23-8.

Thanks so much for your efforts so far, I really appreciate.

[piernov]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Nice!
I don't know from which donor boards you could get that chip. The G718TM1U is available from China on eBay or Aliexpress.

[classicandy]

Re: Lenovo E560 (BE560 NM-A561) not powering ON

Ok. I can get on AliExpress but it would take time (2~3weeks) before arrival which is why I kinda need a donor board. I would browse my schematics to know where I can easily get it.

Its been great chatting with you. Thank you.