LG OM7550 Service Manual

3-10
ONE POINT REPAIR GUIDE
NO BOOTING IN CD/USB FUNCTION
After you turn on power key and displayed message in the following order (HELLO  VOL XX 
CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally.
8-2. CRYSTAL (X500)
8-2-1. Solution
Replace X500 on MAIN board.
8-2-2. How to troubleshoot (Countermeasure)
1) If 3.3 V & 1.2 V is normal, check Reset “High” of IC501 pinT12 on MAIN board.
 If MAIN_RESET isn’t high, check MICOM(IC101) pin40.
2) If MAIN_RESET is high, check the soldering status of 24 MHz crystal (X500).
3) If the crystal (X500) doesn’t oscillate, check R508, R5C5, C502, C503 around crystal (X500).
 If there’s no defective component, then replace X500.
8-2-3. Service hint (Any picture / Remark)
XX
X
I
I
X
X
O
O
X500
< Signal waveform >
< MAIN board top view >
IC501
IC501
X500
X500

LG OM7550 Specifications

General

Brand	LG
Model	OM7550
Category	Stereo System
Language	English