Spectra Power Up Problems

[fire-medic8104]

I have a Spectra Low Power connected to the Motorola Power Supply on my desk at our office. Came to the office and the breaker had tripped in the office shutting everything off. Turned the breaker back on and everything works except my radio. Checked with voltmeter getting 13 1/2 volts on power plug and 13 1/2 on accessory plug. Radio lights turn on like it is going to do the self check and then just go off. Doesn't happen everytime I push the power button, just about every 5th time.

Any suggestions?

[Bill_G]

Check the power supply with the radio connected, and verify you have steady 13.5 during power up. I suspect the pwr sup got bit by whatever tripped the breaker, and now goes soft as the radio pulls current.

[fire-medic8104]

It is actually 14.3 and never moves during power up.

[Bill_G]

Got a second pwr supply to swap in as an A-B test? Your option is to look at diagnosing the radio, and I find it highly coincidental that something tripped the breaker and something in the radio broke on the same evening. Not impossible, but I suspect the power supply has a failure, and swapping in another would help fill in the decision tree.

[Zack08]

It is actually 14.3 and never moves during power up.

Are you scoping that, or is that just a multimeter reading? I've had a spectra do the exact same thing because it was receiving brief power fluctuations during the self test. It took me a while to determine that the radio wasn't at fault....

[Bill_G]

It is actually 14.3 and never moves during power up.

Are you scoping that, or is that just a multimeter reading? I've had a spectra do the exact same thing because it was receiving brief power fluctuations during the self test. It took me a while to determine that the radio wasn't at fault....

Same. I've found the AC and Freq sections of modern VOMs very helpful in spotting noise on a DC line before firing up a scope. Max and min hold are great for finding fast changes you can't see in rolling digits.

[fire-medic8104]

Yeah that is just from a Fluke DVM. I am bringing my Astron power supply to work tomorrow and a power cable to see if that fixes it to isolate the radio or the power supply.

[Lake Effect]

Have you tried to push the Dim button after turning on the radio? If it lost power on the main plug and jumpers in the control head are standard, it will default to no display. I had it happen once and your description sounds exactly like what I saw.

L.E.

[fire-medic8104]

Finally got around to getting the other power supply and have it powering up 2 radios. The one I was having problems with is the same thing. I also tried the original power supply on another spectra and it works. Is there a fuse inside that could have blown? I am not sure what else it could be without doing a little bit more detailed check, which I am not capable of doing. I have replaced the fuses in the maxtracs that is why I am asking.

Thanks

[jackhackett]

there is a fuse inside, but I believe when it blows you will still get a display, you'll just get the fail 01/90. It's on the control board near the front of the radio, you can check for continuity or A+ on both sides when power connected.

see if the radio will key up or make any beeps when buttons pressed, could be a display problem

[fire-medic8104]

No, I get no sound, no beeps, no transmit, nothing. The transmit and recieve light come on and then fade off. I think you are right about the fuse, I think you just get 01/90, but I will check it as soon as I have time. Thanks

[Will]

The fuse would not be the problem from what you say.

Change the control head, an A5 or A7, an try again. The control can do this.

Also MAKE SURE that you have the correct fuses in the cables.

[fire-medic8104]

I think I have a few spare control heads I will give that a try.