Zener diode voltage?

[Tinman]

Doesn’t look like it was easy to collect readings from it in-circuit. Curious how you determined it was bad.

I removed it.

 

[Superduper]

FYI, Next time, you can test it live. Not only will this tell you if it is working, it will also tell you what the zener voltage is too (if it's working properly).

 

[Tinman]

FYI, Next time, you can test it live. Not only will this tell you if it is working, it will also tell you what the zener voltage is too (if it's working properly).

I actually removed the 5 regular diodes along with the zener just to verify.
I probably wouldn't have if there were 20 but 6 wasn't bad.
I convinced myself it was a nad resistor so I tested every single one, nope.
As per instructions I found online, I connected a 1k resistor to the zener then measured the voltage as I increased it with my dc power supply til I hit the 30v max.
The zener kept climbing very slowly and topped out at just over 3v.
I compared it to my new 6v zener which climbed in sync with the ps until 6v then stopped.
At 10.1v, the bad zener was probably passing about 1v.

 

[Tinman]

I received my diodes today.
I just soldered one in and powered it up.
I can see the fm stereo light working when I move the dial so I'm 99% sure it's up and running.
The only thing I'm concerned about (and maybe shouldn't be) is the new one is smaller than the old one so hopefully the original was .5w.
I'll have to wait until I get it together enough so I can get the speakers working to make sure everything is ok.
Here's a comparison of the two:

 

[caution]

The only thing I'm concerned about (and maybe shouldn't be) is the new one is smaller than the old one so hopefully the original was .5w.

Shouldn't matter, but if you suddenly lose the radio again, you'll know where to look

 

[Tinman]

I got this mostly back together.
Radio is working.
The left cassette player is working correctly but the right is still fast.
The voltages on the two inside wires on the fast motor are about 1.5v higher than the other one.
I'll have to try and track where those are coming from and figure out why they're higher.

 

[Tinman]

I've been busy but found/noticed the speed problem with the other player.
Something so stupid and simple that I completely overlooked it.
These pinch rollers aren't really held in with anything.
I noticed the right one was tipped and falling off of it's post so the tape was just being pulled through by the take up reel.
Apparently when I removed them to replace the diode, I pushed the left pinch roller back on without realizing it which is why it suddenly started to work correctly.
I picked it up and slid it on the post and now they're both working correctly.

Now I'm having a problem with the 3.5mm headphone jack on the back of the board.
I worked it with some cleaner and the right side stopped working unless I play with the plug in the jack.
I already had it apart and cleaned the contacts and assumed it was ok but it's not.
It looks similar to an Alps push button switch.
When you insert a plug, it moves the contacts from one side to the other.
Apparently there is something that I missed in the body of the jack.
I'll have to take it back apart and see what I can find.