"n cook" writes:

Sam Goldwasser wrote in message
...
"n cook" writes:

What control signal to the main CD micro would disable spinner drive.
Taking the I/P H(ish) of the releavant 1/4 of the BA6398 quad motor
driver
gets the motor spinning.
Taking the I/P L(ish) of the isolated inv buffer on the BA6398 also
fires it
up.
The signal line to this buffer from pin 25 of the CXD2503 main micro is
not
going negative of mid V neutral.
Focus/tracker coils hunt and sled motor moves on power up but no
spinner.
Both limit switches function

Component CD players won't spin the disc if there is no focus lock due
to dirt, weak or dead laser, etc. If the focus coil hunts but doesn't
stop, there may be no motor drive.

See the CD player repair guid.

I'd never realised there was a focus check before trying to spin up/ extract
any data from CDs.
I looked in a troubleshoot manual for a different make and model
and flow chart is
Does disc rotate - N
Does pick up move - Y
Is laser lit - Y
Is there sound if disc rotated by hand - N -Go to focus section

Right, so I think it's saying that the disc isn't rotating because
there is no focus.

Not looked at further but flow chart continued

Focus section
Does pulse waveform appear at FCSI on processor - N - processor defective
Does pulse waveform appear at FCSI on processor - Y - Is Ramp waveform at
FEO of

focus&tracking IC - N - is there a ramp waveform at FSO
focus&tracking IC - Y - check motor/coil driver IC

This is asying that it's issuing the commands try to focus but the voice
coil isn't doing anything.

Focus before spin isn't universal - portables may not wait, but people should
resist the temptation to immediately blame a coil driver or coil if the disc
doesn't spin.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
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