NX-5K Dual Deck No Power

[tweiss3]

Recently noticed problem (Sunday). NX5700 (1st Deck) and NX-5800 (2nd Deck) to a single KCH-20R head. Power is direct from a BlueSea fuse block (both positive and negative). Positive goes straight to battery, negative bus goes to chassis. Programming allowed both ignition sense or power button to turn it on/off. I had a Alberta Radio crossband remote on/off cable. I have a month window of when this stopped powering up at all since I last used it, otherwise it powers up to a single channel with unselected deck muted.

I traced power, I get 12.8V (car off) at the fuse terminals, and at the pigtail to the VHF deck. The UHF deck is buried and inaccessible without taking an interior panel off. With the UHF still powered, I also see 3.2-3.8V (can't remember exactly) at the pigtail (unplugged) from the VHF deck.

Verified power coming out of the fuse block isn't a false reading by powering up the FT-891, no problems.

First I disconnected the crossband harness. No change (trying to power on the radio with the power button).
Pulled the UHF fuse, left VHF fuse in. No change.
Replaced the UHF fuse, pulled the VHF fuse. No change.
Pulled the fuse for the ignition sense, tried 1 fuse at a time, same results as above.

Am I missing anything that would keep me from spending the hours pulling the decks and head for bench time? Any idea where the problem starts? KCH-20R and NX-5700 was used from Sunny Communications, and the NX-5800 deck was brand new from the local Kenwood dealer.

 

[tweiss3]

To clarify the 3ish volt reading. That is with 12.8V to the UHF deck, VHF deck unplugged. The 3.2V was read coming back out of the VHF deck pigtail. I had expected a 0V reading, but I think I'm seeing 3.8V on the control cables for power.

Also, I am going to pull the KCH-19 head from my truck and swap it in. If it powers up (and should show a programming mismatch error) it would indicate control head issues, if not, I should be able to rule out the control head as the problem.

 

[kd4efm]

let me know over the weekend what you come up with per our email Thomas.
Enjoy the weekend however!

 

[tweiss3]

An update. I swapped on the head from my truck to this car, no difference.
I then pulled the decks out. On the VHF deck, there was water sitting in the rubber cup at the cables into the deck.

A quick bench test, UHF boots up just fine, VHF does not.

Pulled off the KRK15B from the VHF deck and popped the top. Bluetooth/GPS board is toast, tons of rust on the KRK15B board. No evidence of water on the main board or PA, so I swapped out the KRK15B for a spare from the shelf, and now the VHF deck boots up.

So now I need to figure out how to remount these in the car differently. They won't be hidden/hard to get. Also, I will probably swap out for the KAP2 instead of using the 3.5mm out. I think that may have been the way water made its way into the deck, not totally sure though.

 

[mmckenna]

Oh, that sucks. Glad to hear the RF deck is good to go.

Where was it mounted?

I've always tried to consider things like that after my brother in laws Subaru was totaled after water got in during a flood and found the ECU mounted on the floor under the seat.

 

[tweiss3]

Oh, that sucks. Glad to hear the RF deck is good to go.

Where was it mounted?

I've always tried to consider things like that after my brother in laws Subaru was totaled after water got in during a flood and found the ECU mounted on the floor under the seat.

Next to the jack, behind the removable vented cover. I had a CS800D there for years no issue. The UHF was inaccessible without pulling the interior panel (it was the one I was more worried about). I'm sure I'm going to get yelled at wherever I put it this time.

Other than not (maybe) having GPS, or bluetooth (not an issue because its in the 20R head), any other negatives to just leaving that board alone after it dries out?

 

[mmckenna]

Next to the jack, behind the removable vented cover. I had a CS800D there for years no issue. The UHF was inaccessible without pulling the interior panel (it was the one I was more worried about). I'm sure I'm going to get yelled at wherever I put it this time.

Wondering if it was condensation off the window finding its way in there.

Other than not (maybe) having GPS, or bluetooth (not an issue because its in the 20R head), any other negatives to just leaving that board alone after it dries out?

I'd let it dry out and try it, see what happens. Maybe a good soak with contact cleaner to get rid of anything loose. I might be afraid of stuff flaking off and finding other circuit traces and giving you headaches later.

 

[tweiss3]

Wondering if it was condensation off the window finding its way in there.

That's possible. Who knows. I still intend to get things sealed up better and mounted better than they were due to this.

I'd let it dry out and try it, see what happens. Maybe a good soak with contact cleaner to get rid of anything loose. I might be afraid of stuff flaking off and finding other circuit traces and giving you headaches later.

Its sitting to dry, after I wiped the rusty areas down. It was a lot of surface rust on that one board. I'm just not itching to spend $120 for a new board. I'm still unsure if I need to swap out remote cables (KCT17) due to rust on the contacts. That cable is not cheap.