Team Tekno World ke free mobile repairing course mein aapka swagat hai! Main hoon Rakesh Chauhan, aur yeh humara Lesson 37 hai.
Aaj hum mobile motherboard ke “Command Center” yani Power IC (PMIC) ki gehrayi mein jayenge. Dead mobile ko diagnose karne ke liye sahi tarike se Power IC Checking karna samajhna sabse zaroori hai.
Pichle version mein humne sirf coils check ki thi. Lekin ek professional technician jaanta hai ki Power IC sirf voltage nahi deti, wo ek Sequence (Time Table) follow karti hai. Aaj hum complete Power IC Checking process par baat karenge—Input se lekar Output LDOs aur Crystal tak.
Step 1: The Input (VPH Power – Primary Line)
Kisi bhi Power IC Checking process ka pehla niyam hai: Input Check karna. Power IC kaam tab shuru karegi jab usey fuel (VPH) milega.
- Source: Charging IC (DC-to-DC) se nikalne wali VPH Line (3.7V – 4.2V).
- Check: Power IC ke aas-paas lage bade capacitors par 3.7V check karein.
- Advance Fault: Agar VPH line mein shorting hai, toh phone dead hoga aur DC machine connect karte hi High Amp + Beep aayega.
Step 2: Power IC Checking for Output (Buck vs LDO)
Power IC do tarah ke output deti hai. Power IC Checking karte waqt inhein pehchanna zaroori hai:
1. Buck Lines (High Amp, Low Volt):
- Pehchan: Power IC ke charon taraf lagi Badi Grey Coils.
- Kaam: CPU aur GPU ko chalana.
- Voltage: 0.8V, 1.2V, 2.0V.
- Fault: Agar Buck line short hai, toh phone Low Current (0.01 – 0.05) par atak jayega.
2. LDO Lines (Low Drop Out – Stable Voltage):
- Pehchan: Power IC ke paas lage Chhote Capacitors.
- Kaam: Cameras, Sensors, Touch, Display ko stable voltage dena (1.8V, 2.8V).
- Fault: Agar LDO short hai, toh phone ON hone ki koshish karega par Restart ho jayega.
Step 3: Secondary Shorting (The Rosin Method)
Agar Power IC Checking karte waqt aapko Buck ya LDO lines par Beep (Shorting) mile, toh iska matlab “Secondary Line Short” hai. Iske liye hum Rosin Method use karenge:
- Smoke: Rosin (Piroja) ka dhuan pure area mein jama dein.
- Inject Voltage: Jis line par shorting hai, wahan DC machine se kam voltage (1.8V / 2A) dein. (CPU line par 1V se zyada na dein).
- Result: Jo component short hoga, wo sabse pehle garm hoga aur wahan ka dhuan pighal jayega.
Step 4: The Heartbeat (Sleep Clock & Crystal)
Advanced Power IC Checking mein Crystal check karna bahut zaroori hai. Power IC ke bagal mein ek chota sa Rectangular Crystal (32.768 kHz) laga hota hai.
- Test: Multimeter se Crystal ke points par voltage check karein (0.4V – 0.9V aana chahiye).
- Logic: Agar yahan 0V hai, toh Crystal kharab hai aur phone dead rahega, bhale hi Power IC nayi ho.
Step 5: DC Machine Diagnostic Chart (Pro Level)
Readings ko dhyan se samjhein:
| DC Reading (Amp) | Sambhavit Fault (Diagnosis) |
| 0.000 | VPH missing / Power Key Track Open. |
| 0.001 – 0.005 | Sleep Clock (Crystal) Fault / LDO leakage. |
| 0.010 – 0.040 (Stuck) | I2C Line Fault / CPU not responding. |
| 0.060 – 0.150 (Stuck) | CPU Dry Solder / USB Cable Detection. |
| High Amp (Short) | Primary Line (VPH) Short. |
Summary Checklist
Toh aaj humne seekha complete Power IC Checking process. Yaad rakhein:
- Input: VPH (3.7V) OK honi chahiye.
- Shorting: Rosin method se Buck aur LDO lines ki shorting check karein.
- Crystal: 32k Crystal ke aas-paas voltage check karein.
- Buck Coils: Output voltage (0.8V – 2.0V) verify karein.
- Reball: Agar sab inputs OK hain par output nahi hai = Change/Reball PMIC.
💡 Aaj Ka Aapka Task – Lesson 37 (Comments & Forum)
- Practical: Kisi scrap board par Rosin Smoke lagane ki practice karein. (Yeh aasaan nahi hai, dhuan ud jaata hai).
- Comment (नीचे): Kya aapne kabhi dekha hai ki Crystal badalne se dead phone ON ho gaya? Yes/No likhein.
- Forum: Agar DC machine ki reading 0.03 par atak rahi hai, toh video banakar Forum (forum.teamtw.in) par daalein. Hum analyze karenge.
Agla Lesson: Power IC ne voltage de diya, lekin agar CPU (Central Processing Unit) hi so raha ho toh? Agla Lesson hai: “Lesson 38: CPU & eMMC/UFS Fault Finding (Dead Boot & Port Checking)”।
