Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

[platinumsteel]

Hi guys i have a Dell Inspiron 17 5767 with i7 processor and dedicated AMD Graphics.I got as a gift a good couple years now without a charger.It was dead and turned out to be a bad capacitor around the memory IC.Powered on and works.Fixed that issue years ago.But from since then was never able to get past the cannot determine charger message at bios.So i was more of a newbie then than i am now and before I thought the 3v came from the charging block and that only when the bios sees the correct charger then it will allow and send 3v..But turned out i was wrong.So over the course of time I bought 3x OEM chargers for this model and none of them worked. I recently ordered another 90 watt charger for this model and it still doesn't detects.So i went tru this forum again today and i saw a thread where mon2 mentioned that the 3v is needed to power the IC that is in the block of the charger.So i had it wrong all along.I thought the 3v was from the charger block.So now I am hoping you guys can help me check over the circuit to see if the 3.3v is making it's way to center pin and also to the super IO.So i have put up a screenshot of the very first measurements i took.Hoping you guys will guide me further.By the way so far I measured all the resistors values and they all measured correctly.3.3v is present on PR4 Pin 2.But 2.5V on Pin 1.If i remove PQ6 3.3v appears on pin 1 of PR4. When i put back PQ6 i get 0V on Pin 1 of PQ6. Resistance to ground on Pin 1 of PQ6 gives me about 100K.Hoping you guys can help me out and guide me further how to achieve 3.3v on the power jack center pin please. thanks..

[mon2]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

Remove the 33 ohms resistor and test again.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

Remove the 33 ohms resistor and test again.

Okay not to sure if i made a mistake in my previous message i apologize. But i have the 3.3v passing tru the PR4 33k Resistor pins 1 and 2. And i have 3.3v present on pin 3 of PQ6 but on Pin 1 of PQ6 it's 0v there.
Do i still need to remove the 33k resistor PR4 as you requested ?

[mon2]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

PQ4 is 33 ohms, not 33k ohms. Confirm it is 33 ohms on your board.

What is the voltage to ground of pin # 2 of this mosfet?

Next, remove all power, meter in resistance mode.

Measure the resistance to ground of pin #1 of this mosfet. We want to measure the same voltage of ~3v3 at the ps_id pin on the dc adapter connector.

[mon2]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

You do not need to remove the 33 ohms resistor if the value is 33 ohms.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

PQ4 is 33 ohms, not 33k ohms. Confirm it is 33 ohms on your board.

PR4 measures 33.63K confirmed.

[mon2]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

PR4 should be 33 ohms not 33,000 ohms = 33k.

If it is 33k, it is too high and the resistor is defective. It must be replaced.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

PR4 should be 33 ohms not 33,000 ohms = 33k.

If it is 33k, it is too high and the resistor is defective. It must be replaced.

Okay thanks looking feverishly for a 33 ohm resistor. I got mostly Macbook donor boards and not seeing anything 33 ohms.I will check around now and i will get back once i find a replacement.

[mon2]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

The resistor value is not critical if it is a low value. 100 ohm is ok.

In a pinch, you could just bridge it but better to have some resistance to limit the current.

As we all know from Star Trek, resistance is futile.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

My friend Star Trek was wrong.lol .Resistance is not Futile at all..Cause right now I have 3.3v on PQ6 all the way to Center pin Jack on the board..I am still in shock.Your KungFu is great.I would of never picked up on that detail about the 33 ohms.Cause all the other resistors have a K at the end and I honestly didn't notice it's 33 ohms.haha. You solved a big mystery that i have been having with this board for years..haha You are the Mon.Now i will test wiith the chargers i got and see if the cannot be determined goes away or i only need to get the correct charger now.Thanks for brightening up my weekend.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

Okay so am reporting back now with 100% success. No more charger errors and It's recognizing my 90watt charger and charging the battery nicely now. Thanks a lot for helping me understand this PS_ID. Will definitely be able to help me repair future issues like that. I am curious tho as to why that resistor with the wrong values stopped PQ6 from functioning and doing it' job.Can you explain a bit thx.

[mcplslg123]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

@platinumsteel, you are here since 2019. So you should have learned as basic a circuit as PS ID by going thru many many threads with this issue. Its not rocket science but very basic stuff. Its advisable to read all the threads in your spare time to pick up some knowledge. I hope you take it in right spirit.

[platinumsteel]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

@platinumsteel, you are here since 2019. So you should have learned as basic a circuit as PS ID by going thru many many threads with this issue. Its not rocket science but very basic stuff. Its advisable to read all the threads in your spare time to pick up some knowledge. I hope you take it in right spirit.

yes my friend you are so right .The circuit is very basic. i joined the forum in 2019 but i didn't know much about hardware board level repairs at the time I had struggled to understand it.It was only in 2021 that i started to understand the basics and be able to read schematics.I had studied the PS_ID circuit more than my subjects in school lol . I thought i had understood it but i clearly didn't . It was only yesterday i went over the threads with the issue and saw you and mon2 explaining it to someone then i was able to grasp and understand the concept.So i decided to open back up the labtop and try again.And start from the begining where the 3.3v starts.and trace it until it stops.Totally missed the small detail with the 33 ohms instead of 33k on the schematic.lol .And yes i'll take it with the right spirit thanks a lot for the fine advice.

[mcplslg123]

Re: Dell Inspiron 17 5767 PS_ID 2.5V instead of 3.3v

In my early days of repairs, i used to spend more time on various repair forums and understanding schematics then on actual repairs. There are two ways-either you get trained by some expert or learn it yourself the hard way. the later process may be slow but i still prefer the later option. There is no end to learning as everyday we're going to face a new model and a new problem as well.