EDIT 9/28/2018: Replacement of the DC jack was successful and was the culprit for not powering up. Here is my explanation of the complete fix for this radio. You can simply disregard the rest of my replies.I contacted Icom about a replacement DC jack and they got back to me in a reasonable time, sending me a replacement in about a week. After soldering the new DC jack into place and powering the radio via the AC adapter, the radio made audible static and responded to squelch and volume control, but showed no readout on the screen or any other sign of life.
At this point, I tried resetting the CPU via the method of holding the FUNC button and A button while turning the radio on, but the CPU did not reset. (Nothing on the display)
After that, I concluded through some poking around with a continuity tester that the connections between the PTT board and the LOGIC board were faulty; looks simply like they broke from stress over time from pressing the button repeatedly. A reflow of the solder on the joints did the trick and restored the connection between the two boards.
I re-assembled the radio and performed a CPU reset, and the radio is now in operation.
The rotary encoder that works as the tuning knob only registers movement in one direction, but that is a seperate repair for another day.
I learned a lot about this radio, so if anyone has one and would like more information on my insight don't hesitate to contact me, I'd love to help!
Cheers! o7
OLD INFO:So I recently came across an old Icom IC-24AT Dual Band radio in a box of miscellaneous radio items won at an auction for super-duper cheap. Of course, the radio was the only thing of worth in the box. That, however, is not the point.
The version I have came with a standard 6xAA battery case so of course, I put in some batteries and tried booting it up. No avail! The status light failed to come on, and no life could be seen from the poor guy.
I had heard this particular model of Icom had a backup Panasonic VL2020 battery that was required for the radio to run, and the one already installed was far past it's prime. I ordered a replacement, soldered it in place - yet again no dice.
- the battery culprit
Now realizing there's likely a more complex (or simple, I've been known to look over obvious things before) solution, I set out to discover a solution to the fact that absolutely nothing was happening when the radio was plugged in via the battery or the supplied 13.8V wall wart.
A visual inspection led me to be more confused, I checked all caps, connections, etc. Things that would commonly be issues yet none of them seemed out of order in any way.
- (both sides of the power/main board which is likely the culprit, not the logic board)
Poking around voltages when plugged into the wall power shows that the wall wart is actually giving me roughly 15 volts, but using a bench supply with 13.8v doesn't bring it to life either. I don't have much experience with these miniaturized circuits, many things are too compacted to get a good view of, but even then nothing really seems to be out of the order. I'm at a loss!
When measuring voltages that should be the standard Vcc of the radio (15-ish Volts) when measuring them from the ground on the wall wart, they show as 15v. But even when the radio's "on", while measuring from the ground of the radio chassis/motherboard ground it shows a relatively low voltage (0.5-ish Volts).
(voltage when measured from the chassis, which is strangely not connected to the ground on the DC plug??)
It's likely that I'm tired, or stuck in a wild goose chase, but it does seem a bit odd to be behaving the way it is. I'm unsure where to start troubleshooting in a circuit like this, so any and all pointers or ideas are greatly appreciated. I'd skip fixing this guy and just buy a modern Dual Bander, but I'm short on money and I like the way this vintage Icom looks and feels.
A great service manual for my radio can be had here:
http://www.radiomanual.info/schemi/IC24_AT_ET_serv.pdf ( I presume the solution is hidden here somewhere)
If I've left out any vital information please ask and I'll fill in the gaps.
Thanks,
Dane.