Dell 2320 AIO IPPSB-SFA missing rails

[TimT]

Hi everyone

I have a Dell inspiron 2320 all in one seems to have the 19v rail. the power LED is not on. The charger I am using is for another Dell Laptop it has the correct voltage and polarity. Amps are a little low for this computer but should be enough to turn it on or give a power light. Don't know if the sense pin would be a issue.

I have the 19v rail but not the others. I am including a few images with voltages. mosfet 4835D has nothing from drain. I am still learning this and would hope someone could point me in the right direction. a few other mosfets has 19v but nothing from drain. the only areas I could find 3v and 5v are in the images. checked the Bios chip for 3.3 on Vcc but no current at all to the chip.
Any help would be much appreciated

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Test ADATPTER_ID voltage SIO pin 85? Page 49 +3/5V Regulator IC test pin 8 17 23
PL 401 PL 403 Voltage?

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

SIO Pin 85 0v Regulator 8 17 20 0v pl401/403 coils?? 0v. I was thinking 3/5 regulator..but it's not getting any voltage. nothing getting hot on the board..

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

your charger is not recognise by the MB , test the voltage on the middle pin of the charger , test the voltage on the Q9350 DRAIN side must be +19V GATE should be +5V , test voltage PU641 pin 13 16

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

middle pin of charger is 0v so I used a universal charger with Dell connector 11.35v on center pin. checked PU641 pin 13 1.2v pin 16 2.2v I rechecked pins 8 7 13 still 0v.

I am having no luck locating Q9350 I know it's there, I see it in the schematic. I will keep looking. Thanks!!

[piernov]

Re: Dell 2320 AIO IPPSB-SFA missing rails

If it's the same as on laptops, Dell uses a one-wire ROM inside the AC power brick to identify it. The level should be 3.3V, and is powered from the laptop.
This is different to HP which simply uses a resistor between +19V and AD_ID.
They use the same connector, but they are not compatible.
I have the feeling the "universal charger" is for HP, that won't work and may even damage the motherboard.
Use the correct power supply for the machine. (including power rating)

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

so the charger Tip should recive 3.3 from the laptop? if so I can check for 3.3v to the tip
Just checked. 0v going to center pin

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Thanks for your help! I will put this project to the side for now and order the correct power supply.

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

I picked up a new Power supply for the 2320 But, no difference the problem still persist. Anyone have any suggestion's as what to look at next?

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Test ADATPTER_ID voltage SIO pin 85? For Voltage 3.3V this Voltage is pull bown by 2.2k Resester +3VA_EC test that Resester

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Pin 85 and 11 " VCC " @SIO is 0v. the 2.2k Resester is 2.195 I checked pu641 pin 16 "vin" has 1.3v pin 13 "EN0" has 0v. Thanks for your Help! is pu641 the driver for the SIO?

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

TPS51125 pin +19V Test the PR395 PC325 for short +19VSB
Pin 13 ENO must be 1.19V test PR400 PR398 or track it back

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

According to the schematic pin 13 of TPS51125 " pu641 " runs to pr400 and pr394 but on my board pin 13 run to a Via unless I am look at wrong chip. I traced pin 13 to the opposite side of the board. seems to be some cap's and resistors in that area. a few of these has continuity " photo ". pin 16 " vin " of pu641 seems to be shorted to ground. I did not have much time to look at this yesterday, I should have more free time today.

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Put the multimeter in continuity test pin 16 13 to GND to find out if it’s short to GND

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

Sorry I was checking wrong pin before. Pin 13 and 16 are not shorted. I traced both pin's to the opposite side of the board. the both end up at mosfets. one has no power at all. the other is getting 19.5 in but nothing out. in the attached image the mosfet on the left is a 6416 the other is a 6418

[Techtiger]

Re: Dell 2320 AIO IPPSB-SFA missing rails

uplode a close up pic of TPS51125 with the caps & resistors

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

The info I posted for pin 16 was incorrect. pin 16 is shorted to the SIO? a few caps along the way? pin 16 has no trace. So I cannot see were it connects to anything unless it connects to the pad under the ic. pin 13 runs strait to a via and connects to a mosfet. pin 16 has continuity to any ground I touch

[mcplslg123]

Re: Dell 2320 AIO IPPSB-SFA missing rails

If Pin16 of tps51125 is shorted to gnd, then you have short in 19V rail as this pin is VIN for this ic and is supposed to be 19v. If you have dc power supply, then inject voltage on that pin to see what is getting hot.

[TimT]

Re: Dell 2320 AIO IPPSB-SFA missing rails

I ordered a new tps51125 and problem solved! Thanks everyone!!