Sony TC-580 help

[Tennangler]

dankik,
I have that diagram. Hoping you have one ff, rewind, and stop.

 

[Tennangler]

rojoknox,
r715 is showing open.

 

[Tennangler]

rojoknox,
correction, I'm getting 424kohms. had my meter in wrong setting.

 

[Tennangler]

I meant 472 kohms.

 

[dankik]

Hoping you have one ff, rewind, and stop.

I don't but maybe this photo from the web will help. I can't quite see the wire colors.

 

[Tennangler]

Thanks Dankik. That might help. I'm not absolutely sure I plugged them in to the correct tabs on the switches after I unplugged them to remove to screw. The problem with ff going into rewind started happening about that time.I guess I could just move the wires one at a time and retest.

 

[rojoknox]

Greetings from RojoLand!

"r715 is showing [corrected] 472 kohms." OKeh. Proceed to test Q704; desolder it (don't try to test it in-circuit). Does your DMM have transistor-testing facility? If not, I'd hope it has diode-test facilities.

Take care,
—
J. E. Knox "The Victor Freak"

 

[dankik]

The OP has a Klein Tools MM400 (post #121). It has a diode test function. Thanks for helping him.
Here's how to test an NPN transistor with a DMM. You need to put your Klein into diode test mode (2nd function)?


Here are the instructions for your Klein DMM.

 

[Tennangler]

Thanks guys. I will remove and test it tomorrow using the diode test function on my DMM.
James

 

[Tennangler]

I removed the transistor and measured it.
I got .67v in diagram 1 and 2 above and 0 on 3 and 4. So it looks like it is good if .67v is good.
James

 

[dankik]

and 0 on 3 and 4.

You measured 0v when reverse biased, it should be reading OL. If you measure 0 it means that the transistor it is shorted.

 

[Tennangler]

Sorry, I meant OL.

 

[Tennangler]

dankik ,
I unplugged the wires on the stop and rewind buttons and plugged them into the other terminals on their switches to see if that would keep it from going into rewind when I pressed the ff button. I switched them one at a time.
The stop button would not allow anything to move even if it was not pressed.
The reverse whet into reverse as soon as the power was turned on.
Is it likely this issue is related to the no forward play issue or a separate issue?
Thanks,
James

 

[dankik]

Hi. I don't know how the FF & REW switches are wired from your photos.
From what I can tell, there are three different part numbers for the switches so there might be some differences in the type of switch.
Did you get a chance to determine the wire colors for the stop, ff, rew switches?
Can you determine (for each switch type) which connector is the common, normally open, normally closed?