3-9
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.
4-4. SDRAM (IC502)
4-4-1. Solution
Please check and replace IC502 on MAIN board.
4-4-2. How to troubleshoot (Countermeasure)
1) Check below waveform & soldering status of SDRAM (IC502) on MAIN board.
If pin17(#CAS), pin18(#RAS), pin19(#CS), pin38(CLK), pin29(address), pin2(DQ) doesn’t come out,
check damping resistor (R568, R506, R570, R544, R547).
2) If resistor is OK, then replace IC502 (SDRAM).
3) After change IC502, if it is still not below waveform, check IC501 (DSP IC).
4-4-3. Service hint (Any picture / Remark)
} jj
y
V jz
y hz
V ~ l
jhz
IC502
< Signal check point >
< Signal waveform >
Содержание CM8440
Страница 15: ...MEMO 2 2 ...
Страница 19: ...A60L 4 SPEAKER SECTION 4 1 FRONT SPEAKER CMS8440F LEFT SPEAKER ...
Страница 20: ...A60R FRONT SPEAKER CMS8440F RIGHT SPEAKER ...
Страница 21: ...A90 4 2 SUBWOOFER SPEAKER CMS8440W ...
Страница 73: ...3 65 3 66 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW ...
Страница 74: ...3 67 3 68 SMPS P C BOARD BOTTOM VIEW ...
Страница 75: ...3 69 3 70 2 MAIN P C BOARD TOP VIEW ...
Страница 76: ...3 71 3 72 MAIN P C BOARD BOTTOM VIEW ...
Страница 77: ...3 73 3 74 3 FRONT VOLUME P C BOARD ...
Страница 78: ...3 75 3 76 4 MIC PORTABLE P C BOARD MEMO ...
Страница 79: ...3 77 3 78 MEMO MEMO ...