President Mckinley 1011001 no tx/rx.

[Josan]

Hi to all. I'm new here and new on the hobby too and i want to learn so i bought this president mckinley cb radio. It has no rx and tx. The radio powers in but the green light doesn't turns on but i can see it blink when i switch the radio on and turns it off

Hope the gurus here could teach me

Thanks JM

 

[ForestRunner98]

Is it a brand new McKinley?

 

[Smokinone]

This one? Import model with FM

Euro President 1011001 McKinley Radio Maintenance Manual Online Viewing - DocPrime-X.com

Euro President Radio 1011001 McKinley user manual view online without registration and waste of time.

docprime-x.com

 

[AudioShockwav]

That might be a old 40 channel radio built back in the 70's
Am/SSB.
Could be as simple as a bad wire in the mic cord or bad caps that have dried out.


Welcome to the forum.

73
Jeff

 

[Smokinone]

Pictures are always a great help as well

 

[AudioShockwav]

Pictures are always a great help as well

Yes, of the radio and the board will help identify what model it is.

73
Jeff

 

[AudioShockwav]

This is the one I am thinking of.

RigPix Database - CB, "Freeband" and more - President McKinley (1011001)

73
Jeff

 

[Smokinone]

Can't go wrong with an old school President...I may have to drag my old Jackson export out and run it for a while. I think they are one of the best looking radios made.

 

[Josan]

Is it a brand new McKinley?

It'a the old one

 

[Josan]

This is the one I am thinking of.

RigPix Database - CB, "Freeband" and more - President McKinley (1011001)

73
Jeff

Yes Jeff that's the one

73,

JM

 

[Josan]

I check the volatge on the MB3756, here is the reading.
1. 6.5v
2. 13.4v
3 13.4v
4. 0v
5. 13.3v
5. 0.5v
7. NC
8. 0.6v

 

[nomadradio]

That chip appears to be hosed. Either the transmit-only pin 8 will be hot for transmit, or the receive-only pin 6 will be. But if both of them are zero, that's a bad sign. Pin 1 is the kicker. This should be a steady 8 Volts DC all the time, transmit and receive.

Might be wise to check the circuit board pad where pin 1 connects for a short to ground before trying a new MB3756 chip. For that matter, if you unsolder JUST pin 1 and see 8 Volts from the loose pin, that would suggest a short that's overloading the chip's output current. Sure don't want to overload and pop a new chip.

73

 

[Josan]

Thanks for the reply nomadradio. I use the main filter cap as my ground source and i got 8.53v on pin 1 of the regulator but pin 6 still has 0 5v. I ordered a new regulator

 

[Josan]

I checked pin 9 of the and i has 8.59volts but the rest has low voltage pin 6 has only 0.85v.

 

[Josan]

That chip appears to be hosed. Either the transmit-only pin 8 will be hot for transmit, or the receive-only pin 6 will be. But if both of them are zero, that's a bad sign. Pin 1 is the kicker. This should be a steady 8 Volts DC all the time, transmit and receive.

Might be wise to check the circuit board pad where pin 1 connects for a short to ground before trying a new MB3756 chip. For that matter, if you unsolder JUST pin 1 and see 8 Volts from the loose pin, that would suggest a short that's overloading the chip's output current. Sure don't want to overload and pop a

What would be my next step to do after replacing the regulator? Thanks

73