A9/Systems 9000 control head dead?

[AR15Ron]

I have a UHF Spectra in my car (along with a VHF high power and a X9000 low band). I broke the car so it sat for about 6 months and both batteries died (trunk battery just powers the radios). The few times I jumped it and moved it the radios still worked fine. Yesterday I fix the car and drive it around, finally got around to turning the radios on, NOTHING! Now the UHF Spectra control head has a DEK on it, I am using an output from the DEK to trigger a relay the powers the orange/green wires to the control heads for the all the other radios plus my scanner. So nothing turned on at all.

So I noticed the fuse that goes to the wire I use to power the control heads was blown, I put a new one in, hit the switch, blew again. Could not find any shorts or anything wrong anywhere. So I unplugged the UHF radio, swapped the cable with VHF one, tried it again, blew the fuse.

Next I jumped the relay and the low band radio came on, plugged the VHF back in nothing... swapped control heads and it worked fine. Swapped the control cable on the UHF radio, now that one works. Problem is in testing the UHF radio with the control head from the VHF radio I somehow blew up the control head. Even though the UHF one still works... I came to the conclusion the control cable on the UHF radio was bad but it cost me the head from the VHF.

So I'm wondering if there is any kind of internal fuse in the control head I can check? I can't find anything burned in there. I know there is a common capacitor problem and maybe that is what went wrong, no idea. I should probably just throw it out but I can't bring myself to do it without first seeing if I can fix it

I still have no clue why that cable would suddenly be bad either. All the other fuses are fine and swapping the cable fixes everything.. I'll probably cut all the casing off it someday when I have another cable to replace it with but it makes no sense at all to me right now.

Anyone has any insight I'd appreciate it

Ron

[kf4sqb]

No insight, but I do have a .pdf format service manual for the Syntor X9000. I know you are dealing with Spectras, but this manual has schematics and board layouts for the Systems 9000 control head, which is common to both the Syntor and Spectra series. If you think it'll be helpful, give me an email addy, and I'll be glad to send it to you.

[Mike B]

I know there is a common capacitor problem and maybe that is what went wrong, no idea.

There is no problem I'm aware of with leaking control head electrolytic capacitors that would take out a fuse. At the worst, a leaky cap might eat through and break some traces preventing current flow through the fuse. Some heads have a tantalum in the display high voltage power supply that maybe/might cause a high current condition if it shorts????

If the bad Spectra UHF cable took out the low band control head, then why didn't the bad cable also take out the UHF control head? Maybe the low band control head already had its own problem before you tried it on the Spectra.

Normally I would suspect a bad electrolytic capacitor in the low band control head watchdog timer circuit that can cause the watchdog to reset the radio and control head so quickly, that they appear to be dead. However, the blown fuse thing kind of messes with that normal assumption unless they are two separate problems.

Here is some information on the Syntor X 9000 control heads capacitor problem:

http://www.onfreq.com/syntorx/syntorx9k ... ml#ch_trbl

[AR15Ron]

I'm not sure if it's the fuse yet, all I know is it's dead. Totally dead.

The fact that the UHF head still works does make me think that the VHF one was borderline ready to go anyway... Not sure even what would have caused the cable to fail either. All the car did was sit there and the batteries both died. Really strange. Of course the last time I moved the car a few months ago everything worked fine. Now my radios are dead, air conditioning no longer works either. I havent had time to check it any further, hopefully this weekend. Maybe my replacement cable will show up and I can get it all up and running again. Still have not tested my pro-2096 scanner either. I removed it when I found the other problems, hope that is still ok, most expensive thing in the car

Ron

[kf4sqb]

You know, now that I think about it, from your symptoms, I'll bet that you've had a small, furry visitor in your car. What do you think the odds are that you'll find a few wires chewed in two, or at least the insulation chewed off of them, and the bare spots touching something they shouldn't be?

[racerman1cars]

I'll second that idea. that was my first thought, but thought a varmit might have gotten more stuff [wires]
Steve