Dell 3558 (la-b843p), 4th/5th genration board
Prblm - on/off ( tripping issue)
Open tha laptop and che ck all section voltage (check all voltages in ON condition 🔛)
Vin 🆗
3v /5v 👍
Ram voltage 🆗
1.05v pch supply 👌
But,
No core voltage
👉 VR_ON enable signal not genrate
I know,
4th/5th genration board VR_ON signal generate SOC (output)
When,
SOC requirment full
(Vccst_pwrgood)
Then,
SOC release VR_ON enable signal core IC
Check back trace
Vccst_pwrgd signal R707(100k) RESISTER inside voltage ok but no outside voltage
👉Change resister VR_ON 🆗
but board not proper ON
🔙 io chip requirment (NPCE 285)
SYS_PWROK (3.3V) ✅
ALL_SYS_PWRGD (3.3V)👍
PCH_PWROK (NO VOLTAGE)😔
& beep ground
After all,
I check core IC voltage (ISL95813)
All voltage ok
Vr_on (1.5v)✅
Vcc voltage 5v but show (2.5v)
(S5- s0 state)
5v s5- 5v s0 convert by IC (U3601)
INPUT 5V 👍
OUTPUT 2.5V (✖️)
Find one capicitor (c3603) leakage
Its remove ,
Board is proper ON and give core IC vcc pin 5v 👍👍 & DISPLAY COME
