Jerry Wass schreef:
jan olieslagers wrote:
Recently I acquired an Icom A6 in the "Sports pack" version, i.e.
including an adapter for the car lighter plug. This adapter is called
a CP20. Through a slight mistake in my car cabling, I managed to
connect it to the battery the wrong way around, plus and minus were
inversed. Yes yes it's stupid don't tell me. The lighter plug contains
a fuse (8 Amp!) I replaced that but still the radio won't work, I
suppose something in the CP20 blew quicker than the fuse.
NB the radio itself is fine, works like a charm on 6xAA batteries.

Two questions now:
-) how to open the CP20? There seem to be four small covers over screw
heads, but they won't move for any effort I applied. Drill through them?
-) any suggestions as to the CP-20's insides? Schematics, perhaps?
What are the most obvious candidate victims?

TIA,
KA

If you're not into miniature electronics,you probably don't have tools
or parts to repair it anyhow--get friendly w/an avionics tech.

Thanks for thinking along! I do have a temperature controlled soldering
iron with a fine tip, otherwise I'd not even think of opening the damned
thing. And I do know how to use it, yes. Actually I hope to become
established as some kind of aviation electrician - though not an
avionics guru, HF is like black art to me!

As for your other suggestion: yes I hope it is a protection diode blown.
But is that likely? If it is anti-parallel to the input, it should
either be shorted and keep on blowing fuses, which it doesn't, or
completely dead in which case it shouldn't disturb normal operation. If
it is in series, it could also be shorted, still no problem, or have
infinite resistance - but that seems unlikely to me, though I'm not
complaining if it turns out to be that. Will keep you posted?

Jerry, do you agree about (carefully) drilling out the plastic screw
covers? Any other idea?