Noob did a dumb thing

[gashog]

I accidentally reversed polarity to a Uniden 510 pro xl and fried it.
I had just picked up a couple radios and antennas from an old guy for $20 and was bench testing it.
I had determined that the mic cable needed to be resoldered to the connector. I was checking my repair and zapped my radio.

Can it be repaired or did I melt the whole board?
I feel pretty bad because it would have been good to go if I hadn't had a brain **Censored** at the most critical point in the diag.
I'm an idiot!

On the bright side, I did get a 29 Classic circa 1993 in the deal...and I was able to power it up and transmit without ruining it!

[pabxone]

It's most likely only a blown protection diode.

I'll guess the power lead didn't have a fuse in it ?

Have a look on the circuit board near where the power lead is soldered onto the PCB , there will be a diode there (D18) and it's probably blown short circuit.

Unsolder it and replace it with a 1N4003 diode.

It should hopefully be working again after that

[gashog]

I suspect that there is a 20 or 30 amp fuse in the holder. The wires got warm within a second or two.
The 12v power source was a half dead car battery which is probably pushing 10v and wouldn't start a car.
I really feel like an **Censored** and I'm sick over it. Kinda stupid because the radio prolly cost me $5 if you did the math.
The point is, I made such an idiotic mistake!
I'm compelled to try to correct it.

[Deleted User 14541]

Alot of times it is repairable. I fixed a cobra 29 that a fried twice. Replaced the protection diode, a capacitor and repaired a burned trace. He was using those good fuses wrapped in aluminum foil. I guess the thin traces in new radios are good for something

[gashog]

It's most likely only a blown protection diode.

I'll guess the power lead didn't have a fuse in it ?

Have a look on the circuit board near where the power lead is soldered onto the PCB , there will be a diode there (D18) and it's probably blown short circuit.

Unsolder it and replace it with a 1N4003 diode.

It should hopefully be working again after that

Really hope that's all it is.
I probably have one of those "in stock" in have a box of miscellaneous parts left over from two Megasquirt builds I did about 15 years ago.
I'm taking lunch now, but I'll have time to look at it this evening.

-- Saturday, 14 May 2016, 16:52 PM --

I replaced the diode. It was dead shorted.
The radio powers on but there is only very faint static through the speaker. It isn't transmitting or receiving.

[Grinder74]

Pa working?

[MDYoungblood]

The protective diode should have shorted before the radio was turned on so my guess is there was something already wrong with the radio to begin with. The next most likely shorted component is the voltage regulator.

3's

Greg

[gashog]

This little radio doesn't have PA.

It was receiving and transmitting until I killed it.
The only thing wrong was the mic wire. I cut and resoldered it and tested it on the 29.
Works fine now.
My 510 powers up but that's it. Something else must have gotten cooked. I tried the mic off the 29....still nothing.

-- Monday, 16 May 2016, 16:41 PM --

Would anyone here be able to walk me through diaging my broken radio?
Or tell me where I could ask?
I know a 510 Pro xl is hardly worth the effort but I'd really like to give it a shot.

[pabxone]

IC6 ( LM7808 voltage regulator) is worth checking It's likely to have been destroyed in the reversal.

Pin 1 should be 13.8 volts
Pin 3 should be 8 volts.

If pin 3 is NOT 8 volts replace the 7808

[gashog]

$0.44 voltage regulator en route.
Will update.

-- Thursday, 16 June 2016, 16:53 PM --

Replaced voltage regulator.
No change....She's dead Jim!

[47bw022]

Hi gashog

Yes you are just as much an idiot as I am. I trashed a 12volt spectrum analyzer, by reverse polarity the leads I did feel pretty bad about it for a couple of days. Still need to repair it.

I take it, that it did toast after you turned on the radio on the volume/power, right ?

Just trying to be a pain.. have you measured the voltage regulator, or have you just changed it ?
What exactly is the radio capable of right now. Does the display come on ? Hiss in the speaker ? Does it transmit ? How much amps does it draw from the powersupply ?
Does it have burned traces on the solder side of the board ? Any bulky electrolytic caps ?
Need to know. Could you upload a picture of both the solder side of the pcb and the component side, in good quality ?
It might be a bit hard to try to get it back on its feet long distance

Best regards
47bw022 / OZ2DA
Dennis Andersen
Denmark, Europe.