Lenovo Ideapad 305-14ibd... Check This Out

[lorins_core]

Good Day To All.


Laptop Model: Lenovo Idea-Pad 305-14IBD

MOBO PN: ZIWB2/ZIWB3/ZIWB1
LA-B091P REV:3.0 2014-12-22

*PROBLEM : No Display After 3 or 4 seconds turn of. ( Fan Spin then Stop)

I Check The Following Voltages

On Rails 20V - Present
On 3.3VALW - Present
On 5VALW - Present

I try to flash the Rom Bios Not Luck

Check the rails to this Parts (test Actual Plug in the Ac Adapter but system off)

PQ301(AO4407AL_SO8)
123 (S) - 20.4V
4 (G) - 8.5V
5678 (D) -20.4V

PQ302 (AO4455_SO8)
123 (S) - 20.4V
4 (G) - 8.5V
5678 (D) -20.4V

But I notice why? Still 8.5V? either the System check volts turn on and Check turn off as a Same 8.5V? hmmm?


Any Advice

Tia

[piernov]

Re: Lenovo Ideapad 305-14ibd... Check This Out

20V on B+ is fine. (gate voltage at 8.5V is perfectly fine too)
Measure voltage on +CPU_CORE and PLT_RST#

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

20V on B+ is fine. (gate voltage at 8.5V is perfectly fine too)
Measure voltage on +CPU_CORE and PLT_RST#

Sir Here's the Result of Test

Here The Result

+CPU_CORE
OFF= 0
ON = 1.6V

PLT_RST#
OFF= 0
ON= 0


*OHM TEST*

PL1102(+CPU_CORE) = .04 OHM
U3 (PLT_RST#)= OPEN

[piernov]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Check SYS_PWROK, PCH_PWROK, H_CPUPWRGD

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Check SYS_PWROK, PCH_PWROK, H_CPUPWRGD

*SYS_PWROK =
ON =2.3V then Drop Down
OFF=.08 then Drop Down to 0.01V

*PCH_PWROK=
ON= 2.4V then Drop Down 0V
OFF= .60V then Drop Down 0v

*H_CPUPWRGD
I cannot Found on Actual Mobo Part
But I have A Schematic Diagram...
Do you have ViewBoard fo This?


Thanks

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Follow Up for This....


Thanks

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Update For This.

I Try To Change Power iC PU301- Original Part or PN of This BQ24735 Change To BQ24737.

All of The Sudden Not luckily Turn ON. Now Totally Dead Set. i change and Back to The
The Original Part BQ24735. owww..

What Going On.

Voltage Rail

*Before
PQ301(AO4407AL_SO8)
123 (S) - 20.4V
4 (G) - 8.5V
5678 (D) -20.4V

PQ302 (AO4455_SO8)
123 (S) - 20.4V
4 (G) - 8.5V
5678 (D) -20.4V

After
Now ...
PQ301(AO4407AL_SO8)
123 (S) - 23.1V
4 (G) - 23.1V
5678 (D) -23.1V

PQ302 (AO4455_SO8)
123 (S) - 23.1V
4 (G) - 23.1V
5678 (D) - 0V

Any Advice?

[piernov]

Re: Lenovo Ideapad 305-14ibd... Check This Out

BQ247x7 and BQ247x5 are *not* compatible. You have to use the correct one.

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

BQ247x7 and BQ247x5 are *not* compatible. You have to use the correct one.

What Did you think?

The Power Ic. Broken BQ247x7?

[mcplslg123]

Re: Lenovo Ideapad 305-14ibd... Check This Out

What Did you think?

The Power Ic. Broken BQ247x7?

Now you have short in B+ line and thats why pin5-8 of mosfet reads 0v

[mcplslg123]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Remove PR302(to isolate B+ line) and then connect ac adapter. Check voltage on PQ301/302 again.

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Remove PR302(to isolate B+ line) and then connect ac adapter. Check voltage on PQ301/302 again.

I do your Advice remove the Resistor as you said PR302


Reading

PQ301(AO4407AL_SO8)
123 (S) - 24.3V
4 (G) - 24.3V
5678 (D) -24.3.V

PQ302 (AO4455_SO8)
123 (S) - 24.3V
4 (G) - 24.3V
5678 (D) - 0.8V

Other?

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Originally Posted by lorins_core View Post
But do this simple test

I Jumper the PQ302 with back the PR302
Source To Drain

PQ301(AO4407AL_SO8)
123 (S) - 24.3V
4 (G) - 24.3V
5678 (D) -24.3.V

PQ302 (AO4455_SO8)
123 (S) - 24.3V
4 (G) - 24.3V
5678 (D) - 24.3V

The Voltage is Same as Same. Now the PIN no1 & no20 have 24.1 before Nothing Voltage.

1.try to Test press power on unit has been turn on But the Charging light Blinking color Orange.

2.try to Test with Battery Installed. press power on unit has been turn on But the Charging light Blinking color Orange. Fan Spin then 5 sec fan Stop Spin?
Both Light indicator on Power & Charging (Orange) Blinking

I dont Know meybe Sleep mode... hehehe

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

I think it is a one of may Hard Repair incounter...

Although I check the Always Voltage

3.3V now 4.2V

5V now 6.4V

High Voltage?

[ktmmotocross]

Re: Lenovo Ideapad 305-14ibd... Check This Out

way too much but check again. there is not many way to have this high voltages
maybe u have bad battery in multimeter

[on/off]

Re: Lenovo Ideapad 305-14ibd... Check This Out

First, sorry...
just talking about the fact on this thread.

Second. About Your diagnose.

You judge: No display
Symphtom: Power up but then shutdown immediately approx 3-10 second.
General of laptop problems:
-Doesn't react to power button and doen't charge the battery + led the adapter off immediately.
-Doesn't react to power button and doesn't charge battery.
-Doesn't react power button but the battery charging is working.
-Power on but the battery charging doesn't work.
-Power on but then shutdown immediately.
-Power on but doesn't display anything on the screen.

Third. I think that you working repair without any data include schematic, datasheet and learn from experience other people here in this forum section.

Starting from page 1 to 55. all pages must be reading properly.

example page 1 : Information about code board, manufacture, date of release.
page 2 and 3 : Note this!!!. if all system always voltages was Okay (B , 3Valw and 5Valw) you see all peripherals working control by Chipset (in this case Intel SoC-page 1 SoC act as center ).
that is the fact, from RTC (page 7,8 and 13), on/off button (pwrbtn signal-page 9) and other important signals should be trigger by intel Soc. That chip work need external chip for give command for any regulators (a part system power management inside SoC,page 9), that was handle by KBC (SIO/EC) chips. I think for safety SoC itself,
and of course also helped by bios chip as a Basic Input Output System. porpose to power up any voltage that require by Ram, SoC and CPU. As you know when we enter bios setup, only need 3 of components have working fine without sound, lan, hdd and so be attached (like desktop computer)
Reason : #post 1. 20V, 3valw and 5valw were present. so should be to checking what are any important signal to trigger for power plane S3 and S0 state (see voltage rails table).

Fourth : You have done for replacement to fix is far from your diagnose.

No display, but you replace ic of charger.
If 20V, 3 and 5 alw present, 70% that chip is Okay.
the worst thing is wrong replacement part, from BQ737 to BQ735.

Datasheet required to understand "How its Work"
BQ's family chip mostly act as power selector, whether are from adapter or battery source for feeding supply all systems.
see ACDRV and BATDRV signal to trigger gate of mosfet ACFET and BATFET.
BQ737 need P-Channel mosfet for ACFET and BATFET. Gate mostly need signal voltage half from VIN 19V/2 = approx 8V-9V (depend of resistor divider sircuit on schematic).
BQ735 nedd N-Channel mosfet for ACFET and BATFET. Gate mostly need signal voltage VIN+6V = approx 24V-27V.

These only that all what i've known. still far away from the real "how computer is work". Since we are here porpose to digging any knowledge about Troubleshooting laptop.

Really sorry and sad for this happened.

[on/off]

Re: Lenovo Ideapad 305-14ibd... Check This Out

Hope it help:

[lorins_core]

Re: Lenovo Ideapad 305-14ibd... Check This Out

way too much but check again. there is not many way to have this high voltages
maybe u have bad battery in multimeter

hehehe Thanks Man... i think Already to Change little adjust Voltage.

I decided to Change PU301... Same Original and PN:


Answer... Done


the Unit Work Fine... Only the Problem of this Laptop... PU301 i have a extra Unit no display take the PU301. same Part no.

Well the Problem Solve... thanks to mcplslg123 & piernov & on/off for you explanation. you open my close mind for this Model...hehehe. Thanks Again