Mobile Display Light Problem Solution: Display Light Nahi Aa Rahi? (Boost Voltage & EN Signal) | Lesson 21

Team Tekno World ke free mobile repairing course mein aapka swagat hai! Main hoon Rakesh Chauhan, aur yeh humara Lesson 21 hai.
aur ye hai Display Light Problem Solution ke liye.

Pichle lesson (Lesson 20) mein humne Graphics (No Display) problem solve ki thi.

Lekin kya ho agar graphics aa rahe hain (photo dikh rahi hai), lekin “Andhera” (No Light) hai?

Grahak ki shikayat: “Bhaiya, phone on hai, call aa rahi hai, dhyan se dekhne par photo bhi dikhti hai, lekin light nahi jal rahi.”

Mobile Display Light Problem Solution: Display Light Nahi Aa Rahi?

Ise hum Backlight Problem kehte hain. Aaj hum seekhenge Mobile Display Light Problem Solution ka professional tareeka—kaise 3.7V ki battery se 20V se 40V tak ka current banta hai aur “EN Signal” ka kya role hota hai.

Step 1: Diagnosis (Asli Pehchan – Torch Test)

Phone kholne se pehle confirm karein ki yeh Light ka fault hai ya Graphics ka.

• The Torch Test:
  1. Phone ko ON karein.
  2. Andhere kamre mein screen ke upar ek tez Torch (Flashlight) maarein.
  3. Result:
     • Agar halka-halka Logo/Menu dikh raha hai = Light Section Fault (Lesson 21).
     • Agar poora kaala hai = Graphic Fault (Lesson 20).

Step 2: Light Section Ki Pehchan (Hardware)

Mobile motherboard par Light Section dhoondhna sabse aasaan hai. Wahan aapko ye 3 cheezein hamesha ek saath milengi:

1. Boost Coil: Yeh board ki sabse badi coil hoti hai. Iska kaam hai voltage ko “Pump” karna.
2. Rectifier Diode: Yeh current ko wapas aane se rokta hai (One-way gate).
3. Light IC: Yeh driver hai jo coil ko switch karti hai.

Step 3: Connector Checking (Anode Line)

Sabse pehle Display Connector check karein.

• Problem: Paani jaane se aksar Anode Line (Positive +) wali pin jal jaati hai (Kaali pad jaati hai).
• Fix: Agar pin jali hai, toh seedha Diode ke output se Connector tak Jumper maarein.

Step 4: Voltage Checking (Boost & EN Signal) – [Pro Level]

Agar connector saaf hai, toh ab hum Hot Testing (Phone ON karke) karenge. Multimeter ko DC 20V/200V par rakhein.

Test 1: Input Voltage (VPH)

• Kahan: Boost Coil ke ek sire par.
• Value: 3.7V – 4.2V (Battery jitna).
• Result: Agar nahi aa raha, toh power line tooti hai (Fuse/Coil open).

Test 2: EN Signal (Enable Signal) – [Most Important]

• Kahan: Light IC ki ek pin par ya paas ke resistor par. (Schematic dekhein).
• Kya hai: Yeh signal CPU ya Display se aata hai jo IC ko bolta hai “Kaam shuru karo”.
• Value: 1.8V.
• Result: Agar 1.8V nahi aaya, toh Light IC kabhi boost nahi banayegi. Yeh CPU ya Display Connector ka fault hai.

Test 3: Output Boost Voltage

• Kahan: Diode ke dusre sire par (Cathode side).
• Check: Phone ON karein aur wake up (lock/unlock) karein.
• Value: Voltage 3.7V se badhkar 15V – 40V tak jaana chahiye.

Step 5: Troubleshooting Flowchart

Conclusion (निष्कर्ष)

Mobile Display Light Problem Solution nikaalna 3 steps ka kaam hai:

1. 3.7V Input check karein.
2. 1.8V EN Signal check karein (Yeh sabse zaroori hai!).
3. Boost Voltage (20V+) check karein.

Agar Boost ban raha hai fir bhi light nahi hai, toh seedha Display (Folder) badal dein.

💡 Aaj Ka Aapka Task – Lesson 21 (Comments & Forum)

1. Practical: Mobile Display Light Problem Solution ke liye aaj Aap practice board par Diode check karein. Ek taraf reading aayegi, dusri taraf ‘1’ (OL). Agar dono taraf ‘Beep’ hai toh wo short hai.
2. Comment (नीचे): Kya aapko pata hai ki brightness kam/zyada karne ke liye kaunsa signal use hota hai? (Hint: PWM).
3. Forum: Agar EN signal nahi mil raha, toh board ka model number Forum (forum.teamtw.in) par batayein, hum test point denge.

Agla Lesson: Display aur Light toh aa gayi, lekin “Network” nahi aa raha? (No Service / Emergency Calls Only). Yeh bohot complex hai. Agla lesson hai: “Lesson 22: Network Problem Solution (Antenna Switch to Network IC)”।