Superstar 360 fm 8V issue

[mutley]

Hi all,

Currently trying to bring an Ebay special back to life...

The 8V rail is only about 4V and so no TX/RX. I've checked and swapped out the 2SA473, and replaced all the electrolytic caps as a precaution and although there were some pretty bad ones, it's still only 4V.

Nothing seems to be getting warm.

It's got the "stealth" UK 40 board and extra blocks with relays and all sorts so expect I'll have to pull it all out and put back to standard, but wondered if this is a common issue with an easy fix before I go down that route?

Cheers
Nick

[bitbang]

Hi,

If not a short somewhere down the line on the 8v rail which would be my first guess, I would check Zener diode D88, TR40 and D89 in that order. There are voltage tables for the relevant transistors in the service manual (Page 21) that will help you:

https://cbtricks.org/radios/cobra/148gt ... g32_63.pdf

regards

[mutley]

Hi,

If not a short somewhere down the line on the 8v rail which would be my first guess, I would check Zener diode D88, TR40 and D89 in that order. There are voltage tables for the relevant transistors in the service manual (Page 21) that will help you:

https://cbtricks.org/radios/cobra/148gt ... g32_63.pdf

regards

Ah, great stuff! That was it... The Zener had turned its self into a capacitor. Replaced with a new one and all is good. Just needs a good alignment and tidy up now

Thank you!