Sony MBX 247 Laptop Dead. Need help ( Pics attached )

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

No. I think PM6686 is fine. You didn't answer my question about resitance PD27 on pin2.

Iam not sure if my meter is acting up.
If i try to measure the resistance to ground of PD27 pin 2 I get different values.

If set on 20K range Ohms - Result it 2.63 on the meter
If I set it on 200K range ohms - Result is 14.0

How do I know which reading is correct if at all ?

[on/off]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Try replace PR276 and PQ65

[BlueMidnight]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

I'm a little late to the party, but there are a few things I wanted to comment on...

Also I am not sure where exactly is the Power switch connector (CON1) getting the voltage .

The voltage must come from the EC itself. Many of the pins can be configured to use an internal pull-up resistor. The 3V supply is most likely VDD, which did not work until you fixed the charge pump. And that circuit would work just fine with a 10K ohm internal pull-up.

Why do I get a(minus) -3.3 volt on one end of the capacitor PC61 even though I am using the probes correctly ?

If the lower diode in PD27 were not working, or if both the upper diode and PC66 were not working, then PC61 would be on the output of a "negative charge pump" made from PD28 and PC69.

Fortunately, you have fixed this already.

OK I replaced them and now I have around 10V on 15VPCU line .

The output of the charge pump will be the 5V input, plus 3.3V for each of the two stages (the 3.3V comes from square pulses on 3V_DL). That is 11.6V. But you have to subtract the four diode drops (diode forward voltages) as well as the other inefficiencies in the circuit. Additionally, the voltage will drop as the current increases because the capacitors only charge at a certain rate, and the diode drops increase with current.

Iam not sure if my meter is acting up.
If i try to measure the resistance to ground of PD27 pin 2 I get different values.

If set on 20K range Ohms - Result it 2.63 on the meter
If I set it on 200K range ohms - Result is 14.0

A digital multimeter (DMM) is only capable of measuring voltage.

To measure current, the DMM uses a small internal resistance of a specific value and then measures the voltage drop across it.

To measure resistance, the DMM injects a small current into the circuit and measures the voltage it takes to make that current a specific value.

In both cases, the DMM takes that voltage measurement and uses Ohm's Law to figure out what amps or ohms reading to display on the screen.

This is important because, when measuring resistance, the DMM uses different currents and max voltages for the different resistance ranges. Since a diode's resistance changes with current, this means that the different DMM resistance ranges will give you different readings. Different DMMs will give different readings also, for the same reason.

I also notice that PQ59 Pin 4 has only 0.3 volt . Is that normal ?

That signal (3V_DL) is a series of high frequency square 3.3V pulses. You can only reliably measure it with a frequency counter (like that on some DMMs and other tools) or an oscilloscope.

PQ65
Pin 3 - 4.85 Volt
Pin 2 - 0 Volt
Pin 1 - Ground

Here is where you need to be careful. A DMM has an internal high resistance (impedance) that is often 10M ohms, but can also be 1M ohm or some other value. You must always think about how your DMM will affect the circuit. Most of the time, the DMM internal resistance is so high that it will have no noticeable affect, but there are exceptions.

Think about what is happening in this case. There is a 1M ohm resistor (PR276) between ~10V and RVCCD. The resistance between RVCCD and ground is infinite for most intents and purposes. Then you come along and place your DMM's internal resistance between RVCCD and ground. You have just made a voltage divider. And because PR276 has such a high value, the DMM's resistance will noticeably affect the measured voltage.

If 15VPCU is 10V, then you will measure RVCCD as being about 5V if your DMM has 1M ohm internal resistance, and about 9V if your DMM has 10M ohm internal resistance. So, it looks like your DMM is the 1M ohm type.


Back to the main question: Is the 15VPCU circuit okay? If it is switching on the MOSFETs and you are getting voltage on the "+3V", "+5V", and "+3V_S5" power rails, then it has done its job. We can't ask any more of it than that.


Moving on...

Is RSMRST# 3V?

If so, does NBSWON# start at 3V, drop near 0V when you press the power button, and then rise back to 3V when you release the button?

If so, does EC_PWRBTN# start at 3V, drop near 0V when you press the power button, and then rise back to 3V when you release the button?

If so, do SLP_S5# and SLP_S4# rise to 3V after you press the power button?

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

I'm a little late to the party, but there are a few things I wanted to comment on...




The voltage must come from the EC itself. Many of the pins can be configured to use an internal pull-up resistor. The 3V supply is most likely VDD, which did not work until you fixed the charge pump. And that circuit would work just fine with a 10K ohm internal pull-up.




If the lower diode in PD27 were not working, or if both the upper diode and PC66 were not working, then PC61 would be on the output of a "negative charge pump" made from PD28 and PC69.

Fortunately, you have fixed this already.




The output of the charge pump will be the 5V input, plus 3.3V for each of the two stages (the 3.3V comes from square pulses on 3V_DL). That is 11.6V. But you have to subtract the four diode drops (diode forward voltages) as well as the other inefficiencies in the circuit. Additionally, the voltage will drop as the current increases because the capacitors only charge at a certain rate, and the diode drops increase with current.




A digital multimeter (DMM) is only capable of measuring voltage.

To measure current, the DMM uses a small internal resistance of a specific value and then measures the voltage drop across it.

To measure resistance, the DMM injects a small current into the circuit and measures the voltage it takes to make that current a specific value.

In both cases, the DMM takes that voltage measurement and uses Ohm's Law to figure out what amps or ohms reading to display on the screen.

This is important because, when measuring resistance, the DMM uses different currents and max voltages for the different resistance ranges. Since a diode's resistance changes with current, this means that the different DMM resistance ranges will give you different readings. Different DMMs will give different readings also, for the same reason.




That signal (3V_DL) is a series of high frequency square 3.3V pulses. You can only reliably measure it with a frequency counter (like that on some DMMs and other tools) or an oscilloscope.





Here is where you need to be careful. A DMM has an internal high resistance (impedance) that is often 10M ohms, but can also be 1M ohm or some other value. You must always think about how your DMM will affect the circuit. Most of the time, the DMM internal resistance is so high that it will have no noticeable affect, but there are exceptions.

Think about what is happening in this case. There is a 1M ohm resistor (PR276) between ~10V and RVCCD. The resistance between RVCCD and ground is infinite for most intents and purposes. Then you come along and place your DMM's internal resistance between RVCCD and ground. You have just made a voltage divider. And because PR276 has such a high value, the DMM's resistance will noticeably affect the measured voltage.

If 15VPCU is 10V, then you will measure RVCCD as being about 5V if your DMM has 1M ohm internal resistance, and about 9V if your DMM has 10M ohm internal resistance. So, it looks like your DMM is the 1M ohm type.


Back to the main question: Is the 15VPCU circuit okay? If it is switching on the MOSFETs and you are getting voltage on the "+3V", "+5V", and "+3V_S5" power rails, then it has done its job. We can't ask any more of it than that.


Moving on...

Is RSMRST# 3V?

If so, does NBSWON# start at 3V, drop near 0V when you press the power button, and then rise back to 3V when you release the button?

If so, does EC_PWRBTN# start at 3V, drop near 0V when you press the power button, and then rise back to 3V when you release the button?

If so, do SLP_S5# and SLP_S4# rise to 3V after you press the power button?

Excellent Inputs.


+3V_S5 , +3V and +5V is present.

No Voltage on RSMRST#

No voltages on NBSWON.

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Some update :
If I remove PQ67 then the Laptop fan starts spinning on its own when I plug in the adapter. Si guess there is still hope to fix this one.
I have replace the said mosfet twice now and the everytime I put a new one , the voltage on PIN3 of PQ67 is 0. If I remove the mosfet and check the voltage on the pad of pin 3 it shows around 5.
Pin 2 of PQ67 had around 6.5 volts.

Why is there no voltage on Pin 3 of PQ67 as soon as I mount the mosfet, which results in no 3V and no 5V .

[dj_ricoh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Find a macro lens and search for cracks or burn spots on SIO

[on/off]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Some update :
If I remove PQ67 then the Laptop fan starts spinning on its own when I plug in the adapter. Si guess there is still hope to fix this one.
I have replace the said mosfet twice now and the everytime I put a new one , the voltage on PIN3 of PQ67 is 0. If I remove the mosfet and check the voltage on the pad of pin 3 it shows around 5.
Pin 2 of PQ67 had around 6.5 volts.

Why is there no voltage on Pin 3 of PQ67 as soon as I mount the mosfet, which results in no 3V and no 5V .

When you remove PQ67 MAIND signal will as soon as possible you plug in adapter will rise, while this signal should be after RUN_ON goes high.

Consider to check pgood on PU9, i think important.
Also check LID# signal.

Just wonder if 15VPCU still 10V, then drop when that signal on drain mosfet, is it can switch ON PQ62? (only 4.85V, in my logic on/off seem NO)

I guess there's mosfet have leaked on the load switch/discharge circuits

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

When you remove PQ67 MAIND signal will as soon as possible you plug in adapter will rise, while this signal should be after RUN_ON goes high.

Consider to check pgood on PU9, i think important.
Also check LID# signal.

Just wonder if 15VPCU still 10V, then drop when that signal on drain mosfet, is it can switch ON PQ62? (only 4.85V, in my logic on/off seem NO)

I guess there's mosfet have leaked on the load switch/discharge circuits

While I check these, I found that PQ19 Pin 3 has an resistance to ground of only 15 ohms. I removed the PQ19 just to check , then I found that the Pads make a beep noise when I test connectivity of Pin 1 and Pin 3 . The resistance is same on the pads.

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Find a macro lens and search for cracks or burn spots on SIO

I/O does not have any visible cracks or burning effect.

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Consider to check pgood on PU9, i think important.
Also check LID# signal.

Want me check this with PQ67 removed or mounted?

[dj_ricoh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

I think giving voltage and resistance on same spot will help?
If it's not hard ofc

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

When you remove PQ67 MAIND signal will as soon as possible you plug in adapter will rise, while this signal should be after RUN_ON goes high.

Consider to check pgood on PU9, i think important.
Also check LID# signal.

Just wonder if 15VPCU still 10V, then drop when that signal on drain mosfet, is it can switch ON PQ62? (only 4.85V, in my logic on/off seem NO)

I guess there's mosfet have leaked on the load switch/discharge circuits

PU9 PGood2 signal is missing. PGood1 shows 3.3 volt on PU9

Yes 15VPCU is still 10V even after removing PQ67
Power button has 0.5 volt .
Bios pin has 3.3 volt on Pin 1 and Pin 8 .

[on/off]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

First, I think you should check resistor R123 3.3K ohm.
Also seem need boardview for easier to locating that resistor.

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

First, I think you should check resistor R123 3.3K ohm.
Also seem need boardview for easier to locating that resistor.

R123 has 3.3 volt on both ends. And thank you so much for the boardview. I wonder why Pgood2 is not generating.

[on/off]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

PR124 should be present as jumper pad. Test continuity from R123 to Pin28 PU9

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

PR124 should be present as jumper pad. Test continuity from R123 to Pin28 PU9

There is no PR124 and PR125.
There is continuity from R123 to Pin 28 of PU9

From what I can guess - MAIND signal should be generated without removing the PQ67 mosfet. Unless we have that NO 5v or 3V would be generated.

[BlueMidnight]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

By "jumper pad" on/off means that PR124 (and PR125) are not actual resistors on the board. The "S" in "*0_4S" (which probably stands for "shorted" or something similar) means that component is not a real resistor. It may have been a real one back when the manufacturer was testing early versions of the board, but now it is simply a trace in that location.

If there is a very low resistance between R123 and PU9 pin 28, then it is physically impossible for one to measure 3.3V and the other to measure 0V (I assume that's what you mean by "missing"). Double and triple check your voltage and continuity measurements.

And I don't think you ever mentioned what the voltage is on LID#.

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

By "jumper pad" on/off means that PR124 (and PR125) are not actual resistors on the board. The "S" in "*0_4S" (which probably stands for "shorted" or something similar) means that component is not a real resistor. It may have been a real one back when the manufacturer was testing early versions of the board, but now it is simply a trace in that location.

If there is a very low resistance between R123 and PU9 pin 28, then it is physically impossible for one to measure 3.3V and the other to measure 0V (I assume that's what you mean by "missing"). Double and triple check your voltage and continuity measurements.

And I don't think you ever mentioned what the voltage is on LID#.

I am so sorry and you are absolutely right on this. I mistyped the PIN Name. Actually PU9 Pgood1 ( R_5VPGD on PIN 13 ) has no voltage. Pgood2 has 3.3 volt as it should. Apology on that.
I can see why Pgood1 has no voltage because it requires RSMRST# signal which is not present since EC ship is not getting the VDD voltage (+3v )


So i think we have to figure out why MAIND signal is not getting required voltage to trigger the gate of PQ45 .

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

Just an update - I removed PR290 and it the fan started spinning on its own when adapter is plugged in.

I replaced the 1M resistor (PR290) and now we have 15VPCU showing correct voltage of 15V

But there is still no MAIND signal.

What I noticed is that that on one side of PR290 I now have 19V ( VIN) and the other side it has around 6.5 volt. Is that normal ?

[IamPritesh]

Re: Sony MBX 247 Laptop Dead. Need help ( Pics attached )

And I don't think you ever mentioned what the voltage is on LID#.

I actually missed that . Voltages on KU4 Lid Switch are as follows:

PIN 1 - 3.3
Pin 2 - 3.3 (LID#)
Pin 3 - Ground.