Almost sounds like blown pass transistors. Measure the output. If it's around 13.6 VDC or so, then it's your pass transistors which have blown. If they're what I think they are (2N3772), they're relatively cheap to replace.The power was flickering and then went out....today I turned on my radio and the ps does not have the poop to run it....any ideas what is wrong?
Almost sounds like blown pass transistors. Measure the output. If it's around 13.6 VDC or so, then it's your pass transistors which have blown. If they're what I think they are (2N3772), they're relatively cheap to replace.
Almost sounds like blown pass transistors. Measure the output. If it's around 13.6 VDC or so, then it's your pass transistors which have blown. If they're what I think they are (2N3772), they're relatively cheap to replace.
So, how do you know it's the PS and not the radio? Did you try another power source?
Check the numbers on those transistors. They're probably either 2N3771, or 2N3772. but check to make sure what you've got.
They're probably easy to remove and mounted on sockets. If you know how to check transistors, check to see if they're shorted (or open, but more likely shorted).
If not... get a qualified technician to help you.
Astron's are notorious for certain failure modes. Generally, if your voltage is OK at the output, but you can't get current, it's the pass transistors. Occasionally, a component on the regulator board will fail and produce the same result. Check the pass transistors first. If they are good, I would Google "Astron power supply failure modes".Yeah...they look like plug n play....and not expensive....hope that fixes it....would be a major bummer if it is ruined by that power outage.
Astron's are notorious for certain failure modes. Generally, if your voltage is OK at the output, but you can't get current, it's the pass transistors. Occasionally, a component on the regulator board will fail and produce the same result. Check the pass transistors first. If they are good, I would Google "Astron power supply failure modes".
In 99% of cases when a pass transistor fails it will either short, or open. Having 13.6 volts of output with little to no current is an indication neither has happened to the pass transistors. The lack of current is coming from the IC regulator on the board with part number LM-723. Astron mounts this part in a socket since it's prone to failure. Nearly every Astron with these symptoms comes back to life after changing this $1 part.
Very good point, though I have seen shorted pass transistors that passed the 13.8. So, if the pass transistors show good, next step is replacement of the LM-723. I can't think of any other passive components that would fail under a power glitch.In 99% of cases when a pass transistor fails it will either short, or open. Having 13.6 volts of output with little to no current is an indication neither has happened to the pass transistors. The lack of current is coming from the IC regulator on the board with part number LM-723. Astron mounts this part in a socket since it's prone to failure. Nearly every Astron with these symptoms comes back to life after changing this $1 part.