kenwood Tk-790 will not turn on

[Jeremiahsipes]

good evening I have a Kenwood Tk-790 and it is not wanting to turn on. I have not done any mods to it. it has been siting in a truck for some time and just wont work. i tried hooking it up to a battery and pushing the power button and i get nothing. help please

 

[bruch]

Is there a yellow wire on the molex plug and is it configured for ignition sense? If so that wire needs to be hooked to +V.

 

[DeoVindice]

Is there a yellow wire on the molex plug and is it configured for ignition sense? If so that wire needs to be hooked to +V.

That's what I was about to post. Beat me to it!

 

[Jeremiahsipes]

there is the wiring harness on the back that just has 2 prongs for power then there is another wiring harness above that and all that I have to plug into that is an external speaker.

 

[mmckenna]

i tried hooking it up to a battery and pushing the power button and i get nothing. help please

Hi Jeremiah, welcome to the site.

As other suggested, it may be that the radio was originally set up for the 'ignition switched' power function. This function will turn the radio on and off along with the vehicle ignition switch. There's two ways this gets hooked up, depending on wether or not the radio is set up as a remote head or just an under dash radio.

If it's a remote head radio, there is a 12 pin connector on the rear of the control head. To turn the radio on, you'll need to supply 12 volts DC to Pin 1 on that connector.
If it's an under the dash mount, with no remote control head, you'll supply 12 volts DC to pin 1 on the 9 pin connector on the rear of the radio.

Try that and see if it works. If the connector is on the radio, it may or may not be a yellow wire, don't rely on the wire color. Look for markings on the connector showing Pin 1. Depending on what other functions the radio has, there may be other wires coming off those connectors, and not all of them will want to see 12 volts DC connected to them.

 

[msj23195]

Hi Jeremiah, welcome

Like others have said it sounds like an ignition sense issue. To clarify - is this a radio that was working before and suddenly stopped? Or is this a radio recently acquired that you're trying to get to work?

 

[Jeremiahsipes]

thank you for the help. mine has no control head. Is pin 9 negative and pin 1 positive. and do i also have to supply power through the main positive and negative

 

[Jeremiahsipes]

thank you to everyone but i took it to the shop and the guy said someone reversed the polariaty and fried the radio. I like this radio and want one like it can i get some help finding one. and what kind one should i get

 

[cmdrwill]

Is pin 9 negative and pin 1 positive. and do i also have to supply power through the main positive and negative

This IS why most of us have a FUSE in the "yellow" IGN wire. I use a one amp fuse to be safe.

You only need the IGN lead, pin 1. And you need the "MAIN power' And the IGN power to turn on the radio.

 

[62Truck]

thank you to everyone but i took it to the shop and the guy said someone reversed the polariaty and fried the radio. I like this radio and want one like it can i get some help finding one. and what kind one should i get

Most radios have some kind of reverse polarity protection. Its usually a fuse or a thermal resistor located where the power leads come into the radio. Not sure if the TK790 has that, usually changing that out will bring the radio back to life.

 

[mmckenna]

thank you to everyone but i took it to the shop and the guy said someone reversed the polariaty and fried the radio. I like this radio and want one like it can i get some help finding one. and what kind one should i get

Yeah, that'll do it.

The TK-x90 series, as well as many other radios, has a diode between the positive power input and ground. When it sees the power hooked up backwards, the diode shorts to ground. The diode usually sacrifices itself and requires replacement. Not a big job, but bench time is not cheap.

You can find used TK-790's available on E-Bay as well as dealers that specialize in used radios.

These are older radios and are no longer produced by Kenwood. They were replaced with the TK-5710, which will do analog and P25. If analog is all you need, get another TK-790. Since these are older radios, there's value in buying them from a dealer that specializes in used radios as some of them will realign the radio and guarantee them for you.

 

[Jeremiahsipes]

does anyone have pictures. i looked and i cant find a diode between +power and ground

 

[msj23195]

Jeremiah - if repair doesn’t turn out I do have a 790 I’m no longer using, happy to part ways with it. Full function head and external speaker. Feel free to send me a message if you’d like to chat further.

 

[Jeremiahsipes]

Jeremiah - if repair doesn’t turn out I do have a 790 I’m no longer using, happy to part ways with it. Full function head and external speaker. Feel free to send me a message if you’d like to chat further.

that would be awsome thank you