Onix CD-1----Play, no tray

[Gepetto]

If you look at it you are using the bottom section of the IC on page 2 to drive this motor directly based on the way the circuit traces are leading to the connector.

 

[Gepetto]

We will turn you into a digital guy if you aren't careful

 

[laatsch55]

Polarity??

 

[laatsch55]

OK, in auto trigger mode should I have a solid l;ine or a dot moving from left to right??

 

[laatsch55]

Nevermind, just looked at the data sheet. 9--pos, 121 --neg.

 

[laatsch55]

Ok, got the range right. No action on pins 9 or 12. EXCEPT, what look to be a bunch of LLLLLLLLL's all strung together. No change to trace when open/close button pushed.

 

[Gepetto]

Lee those will flip polarity depending on the direction that the tray is going. It is just driving a DC motor so I would expect pin 9 to be at ~6V in one tray direction and ~0V in the other tray direction. Likewise pin 12 will be the opposite, ~0V in the first tray direction and ~6V in the other tray direction.

Guessing that it is a 6V motor but could be wrong, it could be a 12V motor. That IC will drive either.

 

[Gepetto]

what happens if you unplug the last 2 pins of that connector? The IC will drive without the motor connected. My guess is that the motor may be shorted and you are looking at the chip trying to drive it and going into short circuit current limit.

Have you unplugged the motor drive connector and tried just driving the motor in and out with your bench 5V supply to see if the motor is working or not?

 

[Gepetto]

I believe the L's you are seeing is the chip trying to drive the motor but it cannot.

 

[Gepetto]

The chip is short circuit protected so it will hiccup if it senses that it is driving a stuck load.

 

[Gepetto]

I am hitting the sack Lee. Will pick up with you tomorrow nite...

 

[laatsch55]

Yes, i havew driven the 5 volt motor off my bench supply. No burnt motor and have 18 or so spare transports. I get no change to the straight line on pins 6 or 7, need a third hand tho, JANI___

 

[laatsch55]

Ok Joe, goodnight Sir and thanks, when I unclip fro 6 and 7 my horizontal line jumps up 2 diviosions.

 

[jbeckva]

Yes, i havew driven the 5 volt motor off my bench supply. No burnt motor and have 18 or so spare transports. I get no change to the straight line on pins 6 or 7, need a third hand tho, JANI___

If you don't get any change on the inputs 6 and 7 when operating the open/close switch then the problem is back further from there. Any schematic handy?

 

[Gepetto]

What do you see on pin 6 and 7 Lee. You indicate they are flat lined but flat lined at what voltage. When you get back to it, read out the flat line voltage you are seeing on pins 6 and 7. On pins 9 and 12, which one is pulsing with the "L" signal?

 

[laatsch55]

The l signal was a result of having the volts/div on 5 MILLIVOLTS, looks pretty normal at 5 volts. Ok set me straight here. On DC there is no "wave" so a flat line is what i'm supposed to see??

 

[laatsch55]

Jer---the schematic is UNAVAILABLE, I have been begging for some time and it's a no go.

 

[laatsch55]

With the probe ground referenced to pin 14, or 10 the voltage goes from 2 to 0 on the scope, that was for pins 9,12. no action on the open/close button actuation. Pins 6 and 7 will have to wait till after dinner, just got in. See ya in 30.

 

[jbeckva]

What are the static voltages on pins 6 and 7, referenced to pin 10? If both are "low" (less than .3V) and neither goes "high" (>1.5 volts) when the open button is pressed, the problem is behind there. It's a simple circuit... when both are low.. nothing is there on the output. When one is high, the other low, the output should swing to full voltage on one side, zero on the other... then switch around when the logic between the two inputs switch themselves.

In looking at other typical CD circuits, there are limit switches and whatnot on the transport that provide feedback to a "controller IC", which in turn will drive (or refuse to if the switches don't "make sense" to it) the IC you are looking at now.

 

[Gepetto]

Reference Pin 10 as ground, ensure you have a power supply source on pin 5. It should be in the range of 6 to 12V DC on Pin 5. Without that, you will get nothing out of this amplifier chip.

I am assuming that all signals you are looking at will be basic, flat line DC signals. It could be PWMed but I doubt it is that sophisticated.