Pioneer FX-K9 DC-DC converter repairHi

[vincegironda]

Hi I could anyone help repairing an old Pioneer FX-K9 component car radio cassette,

The dc-dc converter looks like it's failed, it there to power the display which isn't functioning, completely dead.

voltage readings on the dc-dc converter as follows

Pin no 1 0.040 v dc
no 2 0.359 v dc
no 4 12.76 v dc
no 5 0.040 v dc
no 6 0.040 v dc
no 7 0.040 v dc
no 8 0.001 v dc

the part number is obsolete so I'm looking for a possible substitute, does anyone have any experience or knowledge of working with this or similar dc-dc converters?
any help or suggestions appreciated.

I have a service pdf if required, thanks

 

[Perry Babin]

Did you take the converter apart to see if you could see a problem?

Many times parts run hot and lead you to the problem.

 

[vincegironda]

Here's a pic inside the converter, not sure how to check or test?

 

[vincegironda]

Underside of converter

 

[vincegironda]

Top cover

 

[Perry Babin]

The only thing that seems like it could be a problem is a possible bad solder connection on the lower capacitor. It could just be the shadow in the image.

Can you connect it to the board with wires to see (with a scope) if there is any activity (oscillation) on the board?

Have you checked the resistors for value and the semiconductors to see if any are shorted?

 

[StoneSet]

Hi,
I recently had the issue with a KEX500.
This is the same DC-DC Converter, the zener diode was out of service, I replaced it by a 30V and it works like a charm !
The original zener is a 33V but it's OK to put a 30V

Regards