tk-830 will not power on

beaujo_fire · Post by **beaujo_fire** » Sun Sep 17, 2006 7:19 pm

I have a tk-830 35w radio. I just received the radio so I do not know if it was working before hand or not, though I was assured that it was when it was purchased.

Currently the radio will not power up. There is a small chance that the radio was miswired for power and accidently reversed the polarity.

The first thing I wish to check is for a reverse polarity diode or other such protection device. Does the 830 series of radio have a diode for polarity protection? If so, can someone tell me which one it is. I have noticed a diode near the power connector. Is this for protection?

I do not have a manual obviously, so if someone on the board here can point me in the right direction I would be greatful.

Thanks,

Dave

Meatball · Post by **Meatball** » Mon Sep 18, 2006 8:14 pm

It does have a reverse-protection diode, but I don't have the manual in front of me so I can't tell you off the top of my head what the markings are. Typically it's a pretty good sized diode sitting across the main power leads where they first enter the radio.

The radio may also be configured for switched ignition. There's a jumper on the upper right-hand side of the top board (J802?) that is cut when the radio is configured for switched ignition. If you carefully push the two cut halves together, you should be able to get the radio to power up.

The idea of the reverse protection diode is that if the radio is connected backwards, the diode will conduct and blow the fuse. The only time the diode will sustain damage is if somebody reverse-connects the radio with no fuse in the main power leads (and you can usually tell if this has happened by smell).

k2hz · Post by **k2hz** » Tue Sep 19, 2006 8:52 am

Meatball wrote:The idea of the reverse protection diode is that if the radio is connected backwards, the diode will conduct and blow the fuse. The only time the diode will sustain damage is if somebody reverse-connects the radio with no fuse in the main power leads (and you can usually tell if this has happened by smell).

As Meatball suggested, I would suspect your problem is the ignition switch control.

It is very unlikely the reverse protection diode is the problem unless it is shorted. If this is the case, the radio would blow fuses, not fail to power up.

The diode is in parallel with the input so if it had burned open it would not affect powering up the radio, it would only mean loss of further reverse protection.

If the radio was connected to reverse polarity and not fused so that the diode burned open, it is likely that the radio suffered extensive additional damage like the microprocessor, regulators and RF power amp destroyed.

Meatball · Post by **Meatball** » Tue Sep 19, 2006 9:05 am

Reverse protection diode= D5 on the final amplifier board.

Switched ignition jumper=W101 on the control unit board (top).

Switched ignition pin=Pin 3 of the 15 pin plug (P4) on the back of the radio. Fuse for 3 amps (fuse and holder included in the KCT-18 Ignition Sense Cable).

beaujo_fire · Post by **beaujo_fire** » Wed Sep 20, 2006 6:14 am

The ignition wire was the problem. Once I hooked that up everything lit up just fine. Thanks for the responses and the help.

Dave

Meatball · Post by **Meatball** » Wed Sep 20, 2006 5:58 pm

We aim to please

Glad it works!