HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

[smaniak]

Hi to all!!!
So I have HP that won't start at all.
There is no power on all coils on the board.
19V goes to Q510. On pin 1, 2 and 3 /source/ - there is 19V. On pin 4 /gate/ there is 19V. NO voltage on drain...
I change Q510 MOSFET with a new one but still the same...
In the attachment, there is schematic for this board.

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

19V on the gate of Q510 will keep it turned off, so it's acting normally. The next step is to find out why it is being told to stay off.

Measure all pins of Q17. Also measure Q29, Q503, and U501.

[smaniak]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

This is my measurements.
On Q501 Pin3 and Pin6 are short.
But I still can't find logic hire.

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

Pin 6 of U501 should be higher than the 5V on pin 5 so that the output of the comparator (pin 8) will become 0V. But pin 6 is 0V instead, so we need to know why.

Try measuring Q16.

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

Oh and to save time, please measure both sides of D10 also. We might need to know that too.

[smaniak]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

Based on your guidelines I measure the components that you told me and I see that there is no LIMIT_SIGNAL.
I see that this LIMIT_SIGNAL is coming from power adaptor, so I change the adaptor and Voila the board is starting!
I have power on the start button, the lights on the laptop are flashing the fan is spinning, CPU and GPU is going hot ... but ... no picture.
So I look at the schematic - GRAPHIC POWER, and measure MOSFETs around there, and I find Q522 that have sort between S and D pins...

[piernov]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

If it's at least a couple of ohms, this is not a short. GPU VCore will always have a very low resistance to ground. The GPU getting hot also tells us than the VCore power is present and not shorted.

EDIT: ah you're talking about Q522, this is not on the GPU VCore power rail, but I guess it's fine too. What's the exact resistance you measure?

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

I agree with piernov. The VCCP rail powers the CPU I/O logic and draws at least a couple amps or more at about 1.05V. This works out to a resistance of well under an ohm.

Since it sounds like the CPU is at least partially powered, you could start by checking H_PWRGD# and H_CPURST# to make sure neither of them is 0V.

For the power rails, it's easier to test the voltages with the board powered. See if any voltage rails are actually missing. If so, find the enable pin on the control chip for that rail and make sure it is being told to turn on. If so, then you can check for shorts and things.

The power rails and their associated enable signals can be found on page 4 of the schematic. But, as a first step, you can just find all the big coils/inductors on the board and measure their voltages before finding out which coil goes to which rail. Next, find and measure the rest of the rails.

[smaniak]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

First of all, I want to answer about Q522 - resistant between S - D pins is 25 oms. Resistant on Q520 between S - D pins is 50 oms. So I decide to change Q522 with a new one... - but and with the new one, resistance is 25 oms...
If I turn on the board and live it to work, after turn it off - Q522 - resistant between S - D pins is 13 oms. Resistant on Q520 between S - D pins is 26 oms... Both are changed with new ones, and the result is the same.

H_PWRGD
I can't measure H_PWRGD, because I can't find R658, but I can measure H_PWRGD_XDP on CN24 -leg 39 - 1.050V

H_CPURST
CN24 -leg 46 - NO V

Coil voltages are in pictures below.
Is it normal L501 - 0.8V?
And why there is no voltage on H_CPURST?

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

L501 is on the battery charging rail. Since I assume you don't have the battery connected at the moment, that is fine.

Because CN24 is not populated, it's possible that neither is R757. And that would prevent the H_CPURST signal from reaching the pad at CN24. It is unfortunate that they don't label all the components on this board. I don't have a boardview for it, so the only way to find a spot to measure H_CPURST would be to search continuity between CN24 and various pads/resistors around CN24 and the PCH (on both sides of the board) to find R757 (or, at least, the pads for it). That's probably not the most fun thing to do..

A couple power rails are required to produce the ones you measure, so we can call those good. The only one I see that isn't accounted for is the 0.9V rail used for the memory. You'll find that on pin 3 of U27.


Other thoughts...

If it seems to be powering up, but is definitely not running (e.g. no HDD activity), and is giving no video, then the main BIOS may be corrupt. Or there could be something worse going on. If there were HDD activity but no video, then it could just be a graphics/screen issue.

If you have an oscilloscope, it's possible to watch the data line on U21 and see the EC firmware being read, followed by the system firmware.

Make sure you have known-good memory installed while testing the board. And plug in the speakers in case you are getting any beep codes.

[smaniak]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

So I try to find this R757 resistor, but I couldn't.
I measure pin3 on U27 there is 0.9V
I think there is HDD activity, because when I connect lights on the board, the light for HDD is blinking every ~2 seconds...
I change the memory with another one, but still the same...
I plug speakers - no beep codes.

I don't have an oscilloscope, but I decide to take off the BIOS and check it with programmer, and flash it with the new firmware...
I'll leave comments when it's done.

[smaniak]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

I have one "good" news, it seems that the BIOS chip is corrupted.
I try to flash it with a new one 3 times, but it gives me an error in one sector...
So I'll purchase a new one and I try again.

I want to give little info, how I manage to run SIVAVA / www.sivava.com / Programmer on LPT on Windows 7 64bit.
First of all try to find PC with LPT on the motherboard, because I lose 2 days trying run it with PCI-to-LPT board, and I couldn't.
To run it on 64bit Window you must follow this manual - https://www.downtowndougbrown.com/20...dows-7-64-bit/
This gay explain how to run it with PCI Express 1x card. This didn't happen to me /maybe it depends on card manufacturer.../, but the rest of the post is OK.
Follow the manual on SIVAVA Programmer to install the board.
Next for the software part. On the SIVAVA disk there is a bunch of software releases, and at first, I'm wondering why, because everyone will choose to work with the newest one... But in my case, it works with Version 0.98D12a /that is one version older/.
When you start the program you must choose LPT port, and test the hardware with menu Help -> Test Hardware. If the status bar show "Hardware present" everything is OK.
Next form Device Select in my case I chose SST25VF016B. You must arrange pins from 1 to 12 according to the picture shown in the software.
Positioning the chip on the programmer board is shown in the picture below.
When you press "Electronic ID" the software must show Manufacture and Device code.
The programming process is standard...
I'm writing this because I spend 2 days trying to run this thing...

When the new chip arrives, I'll leave feedback.

[BlueMidnight]

Re: HP Compaq 6730B INVENTEC 6050A2219901-MB-A03 won't start!

Thanks for the info. I'm sure it will be helpful to someone with the same programmer.

I'm glad you found something misbehaving that you can replace. That's much better than finding no explanation at all. Now we just have to wait and see if it was the cause of the problem you were trying to fix, or if it was just an unrelated problem. Good luck!