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

[laatsch55]

I know, I was wrong .

 

[jbeckva]

Ok, so where'd ya see a decent high/lo or lo/high transition at? Anywhere?

What is the static dc voltage (no button pushin) on pins 5,6,7,9 and 12 referenced to pin 10?

 

[Gepetto]

Not following Lee. Do you have 5V on pin 5? Pin 5 is critical to have a decent power supply voltage or nothing is going to happen at the motor.

 

[laatsch55]

Just rigged a set of mini-grabbers for the power supply, tray motor goes for 1/2 second at 2 volts. Jer there is a slight up, down movement on pin 6 with button pushoingh. I'll check all static, hang on.

 

[Gepetto]

Minimum supply voltage on the TDA7073 is 3V so in order to do anything you need more than that.

 

[laatsch55]

#5---5volts
#6---2-1/2 volts
#7---2-1/2 volts
#9-=--2-1/2 volts
#12 ---2-1/2 voltys

 

[Gepetto]

OK that is the steady state do nothing to the motor mode. Seems right. What happens now when you hit the button? You should see 6 go higher and 7 go lower or vice versa.

 

[laatsch55]

OKL hang on.

 

[laatsch55]

6 goes a volt higher on open, 7 goes a volt higher on close

 

[Gepetto]

OK that seem right

 

[laatsch55]

9 and 12 act right, steady at 2-1/2 then a 2-1/2 volt bump, but it only lasts for a half second.

 

[Gepetto]

On open when pin 6 goes a volt higher, you should see pin 9 go high and pin 12 go low.

On close when pin 7 goes a volt higher, you should see pin 12 go high and pin 9 go low.

 

[Gepetto]

If you do not, I would say that it is time for a new TDA7073 chip.

 

[laatsch55]

7 is really sluggish, hard to tell if there's any voltage change. So does it take 5 volts to get it moving the drops to 2-1/2 for the rest of the journey until the limit switch interrupts it?

 

[Gepetto]

On open, does 6 go a volt higher and stay there (static high) until it hits the limit switch?

If it does, this is a good sign. The TDA should respond in synch with that, it has a gain of 100 so it should amplify the hell out of the 1V signal you see on pin 6 by sending pin 9 high and pin 12 low. Does it do this? (The Philips data sheet is really crappy so I am guessing about polarity)

 

[laatsch55]

No it doesn't stay up, then back down. Same with 12, 9. Up then back down immediately.

 

[jbeckva]

What is the maximum voltage you have seen between pins 12 and 9, Lee?

 

[jbeckva]

In other words, 12 referenced to 9 or vice versa.. max VDC?

 

[Gepetto]

I think you are getting close to putting a resistor on the output instead of the motor as a load to test this.

 

[Gepetto]

Put a 10 - 15 ohm resistor where the motor is Lee and see if it will drive the resistor properly or not. If it will not drive the resistor then it is time to go for the throat of the TDA.