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Only for training and service purposes.
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.
4-2. CRYSTAL (X500)
4-2-1. Solution
Replace X500 on MAIN board.
4-2-2. How to troubleshoot (Countermeasure)
1) If 3.3 VA & 1.2 VA is normal, check reset ‘High’ of IC501 pin T12 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 R5B4, R5B6, C5B2, C5B5 around crystal (X500).
If there’s no defective component, then replace X500.
4-2-3. Service hint (Any picture/ Remark)
XXI
XO
X500
< Signal waveform >
< MAIN board top view >
IC501
IC501
X500
X500