Need help with a Cobra 148 gtl. (Philippines)

[RBR762]

Ok..........I picked up a nice and unmodified 148 gtl that would not power up for 60$.….....… So when I got it I hooked it up to the Astron 35 amp and as soon as I turn on the switch on the radio the power supply goes into crowbar protection.......volts drop down to nothing but when I turn the radio back off then the power supply goes back to normal 13.8 vdc
So I order a cap kit and replace all the caps and it still puts the power supply into protection mode
Tonight I changed the am regulator to a NTE152 but that didn't solve the problem
Any suggestions as to where to look next......please don't tell me to start pulling the ceramic caps.........lol.
.

[WDX107]

Is the power supply working correctly
If it is have you hooked the radio up mobile or another way to make sure if it even works or the protection diodes blown

[RBR762]

Power supply works.........pulled protection diode and it is fine. Thanks for responding!

[nosaj]

So are you saying it's working now? Instead of blinding replacing parts how about a little sleuthing first?
Another common thing that will do what you describe is a shorted final.
Here are some links to the radio
[Please login or register to view this link][Please login or register to view this link]

nosaj

[RBR762]

No.......the radio is still not working just stating that the power supply is working and that I pulled the safety diode and it checked out fine. Going to separate the final from the circuit next and see how it goes.

[RBR762]

Separated the final and driver and still no luck..........

[RBR762]

Stayed up late but figured it out......D44 was bad.
The Cobra technical bulletin said to replace with a 18v zener diode.......might have to order some and do just that. Thanks for all who responded and helped.
Robert

[nosaj]

Awesome... I'm glad you got it..

nosaj

[MDYoungblood]

I missed this post for some reason,, getting old for sure,, glad to hear you got it figured out.

3's

Greg