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Old 07-05-2018, 11:28 PM
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Exclamation Kenwood TK-790 - Won't power up

Hi all,

I have a TK-790 VHF radio. I was having squelch issues and I noticed that if I connected the mic it would stop. I decided to short out a pin and the radio stopped working.... The mic holder is connected to the power supply (I did not to that). My guess was a grounding issue.

I think I might have blew something up because the radio won't turn on now. Can someone please help me with this. Is their a fuse inside that I might have popped?
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Old 07-06-2018, 7:25 AM
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Hi all,

I have a TK-790 VHF radio. I was having squelch issues and I noticed that if I connected the mic it would stop. I decided to short out a pin and the radio stopped working
Which pin? Which connector What did you 'short' it to?


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.... The mic holder is connected to the power supply (I did not to that). My guess was a grounding issue.
Do you mean the mic hanger was mounted to the case of the power supply?

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Is their a fuse inside that I might have popped?
There are internal fuses, but without some details, we would just be guessing.
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Old 07-07-2018, 4:03 PM
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Which pin? Which connector What did you 'short' it to?
Well I used a wire to connect I think pin 1 may be pin 12 to the mic hanger with is connected to the power supply.




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Do you mean the mic hanger was mounted to the case of the power supply?
Yes.

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There are internal fuses, but without some details, we would just be guessing.
I will add a photo later tonight.

Last edited by vraho10; 07-07-2018 at 4:05 PM.. Reason: Edit
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Old 07-07-2018, 5:33 PM
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Well I used a wire to connect I think pin 1 may be pin 12 to the mic hanger with is connected to the power supply.
Pin 1 of the mic connector has 12 volts on it. Kenwood calls this "SB", basically it's teh 12 volts that is controlled by the power swtich. If you grounded that to the mic hanger then likely you popped the fuse for the control head power.

Fuse 502, a 1.8 amp chip fuse, is located on the control board, right behind the ribbon connector that goes to the control head.
Kenwood Part Number F53-0108-05
Nothing special about it. You could find a 1.8 or 2 amp fuse of similar size and package and use that.
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Old 07-07-2018, 5:46 PM
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One of these would work:
https://www.amazon.com/LITTELFUSE-04...m+Chip+Fuses+2

You'll need a fine tip soldering iron, a very steady hand, a pair of small tweezers and an abundance of caution.
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Old 07-09-2018, 1:33 PM
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Quote:
Originally Posted by mmckenna View Post
One of these would work:
https://www.amazon.com/LITTELFUSE-04...m+Chip+Fuses+2

You'll need a fine tip soldering iron, a very steady hand, a pair of small tweezers and an abundance of caution.
I will do that and get back to you on the repair. I have yet to upload a image of the set up but I will soon!

Thank you!
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Old 07-11-2018, 7:28 PM
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Quote:
Originally Posted by mmckenna View Post
One of these would work:
https://www.amazon.com/LITTELFUSE-04...m+Chip+Fuses+2

You'll need a fine tip soldering iron, a very steady hand, a pair of small tweezers and an abundance of caution.

Approx. what temp can the fuse get to before itís unusable?
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Old 07-11-2018, 8:47 PM
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You'd have to check with the manufacturer.
Basically you use whatever is enough to get the solder to flow.
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Old 07-12-2018, 2:40 PM
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You'd have to check with the manufacturer.
Basically you use whatever is enough to get the solder to flow.

Do you have a diagram of where the fuse is located? I know you told me where it is located.
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Old 07-12-2018, 5:09 PM
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PM me your e-mail address. I can send you what you need.
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Old 07-27-2018, 11:21 AM
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Default Sensing.

Hello.. were you able to get it powered up???
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