Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

[QUOTE=BlueMidnight;977977]Let's check the AC adapter. I think I mentioned this early in the thread, but I'll say it again. Plug it in and measure between ground on outside of the barrel and positive on the inside of barrel. It's okay to touch the center pin as long as you are also touching the inner surface of the barrel (otherwise you will probably get a reading that is about a volt too low).

As long as the voltage is within reason (~19.5 volts) and stable, continue...

Next, let's check some of the voltages with the power supply plugged in.


Measure the voltage at the following components. You only need to measure one pin from each:

PR103 (main +VIN power rail)
PL12 (3V switching regulator output)
PL15 (5V switching regulator output)


Let's also check the 3V (+3V_ALW) and 5V (+5V_ALW) linear power rails, as well as the AC adapter identification signal (LIMIT_SIGNAL). See attached pics. Note that the arrow is pointing to one specific side of the indicated component.[/QUOTE AC adaptor is 19.5V steady. All other components are missing their voltages, reading are in the mv range.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I also have a second board that I have been following along with the first one, and It has all the voltages present that you asked me to test. original does not have the voltages present, but second one does. I want to fix both.

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

Ah well it looks like those boards are going to diverge from this point, so I will talk now just about the one with no voltages...

With the adapter plugged in, measure the voltage on pin 1 and 6 of connector CN11. It's the one the DC jack plugs into. If you get voltage on those, double check the voltage on LIMIT_SIGNAL from the pic in my previous post.

I'm also interested in the voltage on the source, drain, and gate of PQ5 and PQ9.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

Ah well it looks like those boards are going to diverge from this point, so I will talk now just about the one with no voltages...

With the adapter plugged in, measure the voltage on pin 1 and 6 of connector CN11. It's the one the DC jack plugs into. If you get voltage on those, double check the voltage on LIMIT_SIGNAL from the pic in my previous post.

I'm also interested in the voltage on the source, drain, and gate of PQ5 and PQ9.

Ok, connector CN11 pin 1-19.46V pin 2 19.46V pin 6 1.3mv PQ9 all pins read in mv range between 1.3mv to 3.4, except gate in144.2mv. PQ5 pins1-3 in mv range, gate, 146.2mv pins 5-8 19.46V:

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

So PQ5/PQ9 are not being told to turn on. Makes sense if CN11 pin 6 (LIMIT_SIGNAL) is too low.

Do you have another AC adapter to try?

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

no , the one i'm using is an OEM original.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

So PQ5/PQ9 are not being told to turn on. Makes sense if CN11 pin 6 (LIMIT_SIGNAL) is too low.

Do you have another AC adapter to try?

Are you talking about the adaptor that plugs into CN11 or the actual powersupply. I do have another adaptor that plugs into CN11. I will try the other one, ans see if things change.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I tried the other adaptor with no change, pin 6 0.2mv

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I'm not sure what the deal is there. The lowest value the math gives me, even allowing for shorted FETs and/or capacitors, is roughly 100 mV (0.1 volts).

Check if the multimeter is accurate. Make sure it reads 0 volts when the leads are touching each other.

With power disconnected, what is the resistance from CN11 pin 6 to ground?

You could also try measuring the voltage on the center pin of the AC adapter. But that's tricky, so instead try using one of the DC jacks you have to help you. Don't plug it into CN11. Instead, just plug the AC adapter into the jack and then probe the connector. If they are using the standard colors, then the brown wire is the one that goes to pin 6. For ground, use either one of the black wires or just the metal case of the DC jack.

Most multimeters should read a little over 18.5 volts for the center pin.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I'm not sure what the deal is there. The lowest value the math gives me, even allowing for shorted FETs and/or capacitors, is roughly 100 mV (0.1 volts).

Check if the multimeter is accurate. Make sure it reads 0 volts when the leads are touching each other.

With power disconnected, what is the resistance from CN11 pin 6 to ground?

You could also try measuring the voltage on the center pin of the AC adapter. But that's tricky, so instead try using one of the DC jacks you have to help you. Don't plug it into CN11. Instead, just plug the AC adapter into the jack and then probe the connector. If they are using the standard colors, then the brown wire is the one that goes to pin 6. For ground, use either one of the black wires or just the metal case of the DC jack.

Most multimeters should read a little over 18.5 volts for the center pin.

Multimeter is a klein MM200 probes touching 0 CN11 pin6 to ground is 62.0K ohms First jack with power on brown wire, pin 6 reads 18.55V second jack 15.24V

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

Multimeter is a Klein MM200 when probes are touching 0V CN11 pin6 to ground reads 62.0K ohms. With power to pin 6 brown wire, on DC jack,reads 18.55V On second DC jack reads 15.24V

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

Well I don't know if this is the main problem or not, but there is something not correct here, so it's worth exploring. We need to at least trust the the AC adapter and DC jack are perfectly okay, or we could end up on a wild goose chase checking other stuff.

62k ohms is exactly what the schematic indicates (the path from PR158 down through PR157). 18.55 volts is good if your multimeter has 10M ohms of internal resistance and your AC adapter is 45W (which has a ~500k ohm resistor on the center pin).

The things that are not okay are the 0.2~1.3 mV you measured earlier on CN11 pin 6 with the board powered, as well as the 15.24V you measured on pin 6 of one of the DC jacks while disconnected from the board.

The easiest way to explain all of those readings would be a very high resistance on the center pin somewhere in the AC adapter. That would indicate some kind of bad solder joint or broken wire inside it. You did get a good reading of 18.55V with one of the DC jacks, but perhaps it intermittently makes good contact.

Explaining those measurements if the AC adapter is good is far more difficult. It would require some intermittent short on the board plus one of the DC jacks being bad, for example. Seems far less likely, though nothing is impossible.

One other test you can try is to connect the AC adapter to the DC jack. Do not connect them to the power outlet or to the motherboard. Then you can measure the ID resistor in the jack by checking the resistance between the red and brown wires (pins 1 and 6). The correct value for a 45W AC adapter is roughly 500k ohms.

Now try that measurement, and the other ones you've done so far, again. Try both DC jacks. Try wiggling the wires and plugs around. Etc, etc. You're looking for anything that is inconsistent between tests or between the 2 DC jacks, etc. Let me know if you find anything interesting.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I will try what you suggested, both dc jacks are unbranded chinese junk. I cant seen to find anything that is an OEM original. I think I purchased another power supply too, i'll have to look for that one. so you think the board and connector CN11 are ok, probably something wrong with dc jack, or power supply. I did try powering back up, and still not getting any voltage on pin 6, with the good dc jack. the one that measured 18.55V. I play around with it, and see what happens. Let ya know. Thank you for all your time with this.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I do get 496M ohms with that resistance test you mentioned. I think the problem my lie with both adaptor and jack. I'ts happening to the other boards as well. so there are three doing the same thing. no power on pin 6.What are the odds of that happening. 19.46V on pins 1 and 2. pin 6 0.1mv I can get new DC jack and power supply and see what happens.

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I'd like to get some confirmation on whether that was a typo. 496k ohms would be perfect. But, if you are getting 496M ohms, that would be far too high. It would solve the mystery though.

Either way, it does raise an eyebrow if the same thing happens no matter which board you plug that AC adapter into.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I will double check that reading, but I'm pretty sure it read 496M ohms,and not K ohms also can you explain why that adaptor works fine, and charges my laptop, but doesn't work with the extra boards I have for replacements. Can I damage my working laptop using this power adaptor?

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

If it is an issue having to due entirely with the center pin having high resistance, then it should pose no danger to the working laptop.

I'm not entirely sure at this point if it's the power supply or the DC jacks alone that are to blame. You had a bad reading with one of them, but if the other is bad in some way also, then that would explain why the laptop is working. More experimentation is needed.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I will double check that reading, but I'm pretty sure it read 496M ohms,and not K ohms also can you explain why that adaptor works fine, and charges my laptop, but doesn't work with the extra boards I have for replacements. Can I damage my working laptop using this power adaptor?

I double checked and that reading is correct. It's 496M ohms.My working laptop has the original Oem parts. Those DC jacks are the chinese junk you see for 6-8 dollars. The power supply is used OEM original, but who knows. I can get new, to see if there is a difference. those DC jacks don't seem to fit CN11 right to me. looks like they could push in a little more, but they don't, and I don't want to force it in.

[BlueMidnight]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

Yeah, that amount of resistance is very wrong. Measuring the resistance between the center pin and inside surface of the barrel directly would be helpful, but it's just so small.

Since your laptop seems to like that power supply, we could just assume it's a problem with the DC jacks and order another. Or, if you feel like getting some extra proof, you could disassemble the laptop and borrow the jack to do the same resistance measurement and also the voltage measurement on CN11 pin 6.

[rccrasher65]

Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on

I'll order a new power supply, and DC jack, should take probably 5 days at most. last resort to disassemble laptop, only problem I'm having is that my screen blinks when I use a few keys like my backspace key. Don't know if something has loosened up or what is going on. Drivers and bios are all up to date. Let me know what else we can try. We have the other board that has all the voltages, we were testing for.