Marantz SA8260-no disc

go2shing

請教各位, 部機換咗頭聽唔夠廿次又話no disc. 不過今次入碟後係唔識轉, 我記得上次攞去抉換頭前拆過抹頭係識轉。謝謝!

billymud

I think ur SA8260 has power supply problem.  In that case, it exhibits no disc at an earlier time, and now 入碟後唔識轉.

if there existed unstable +5v/+12v (ie. poor voltage requlation ), there would be "NO Disc" and/or " No Spindle" symptoms.  

go2shing

billymud 發表於 2016-4-17 03:52
I think ur SA8260 has power supply problem.  In that case, it exhibits no disc at an earlier time, a ...

謝回覆, 我先檢查電源部份。

go2shing

再說多一點就是入碟後有紅光, 光頭前後微動一下就停, 之後出no dise。

billymud

go2shing 發表於 2016-4-17 08:36
再說多一點就是入碟後有紅光, 光頭前後微動一下就停, 之後出no dise。

入碟後有紅光 menas the Laser Power is working,
光頭前後微動 means the Tracking is working,
as Spindle motor is not working (ie. due to no power, defective motor, voltage drop,...etc), the Servo chip gets no signal;
as a result, 光頭微動一下就停, uP sends "NO DISC" to display panel.

billymud

go2shing 發表於 2016-4-17 08:33
謝回覆, 我先檢查電源部份。

extracted from SA8400 service manual, fyi.

go2shing

十分多謝Billy師兄, 檢查電源後再次請教。謝謝!

go2shing

我已經試過, 係無電比轉嗰個麼打。請問邊度出問題多? 謝謝!

go2shing

當TOC reading時有12mV, 但應該唔係真有電輸出嚟

billymud

go2shing 發表於 2016-4-17 12:03
當TOC reading時有12mV, 但應該唔係真有電輸出嚟

measure the output voltage of +12v and +5v right after the requlators (as attached on heatsink).
power on the player for 15 minutes before taking voltage measures !  ..... that might be able for u to identify a potential overheated requlator.
12mv is definitely a wrong for the spindle motor to be operational.