[Kenwood] ASTRON RS-35M

[Tim Billingsley]

On Oct 29, 2016 15:22, "Tim Billingsley" <kd5ckp at gmail.com> wrote:
>
> Is anyone aware of a good "for dummies" troubleshooting guide for Astron
or just power supplies in general? I would prefer something specific to
Astron.
>
> "For dummies" may be taking it a bit far, but step by step would be good.
Symptom/probable cause/probable solution would be best. I have only
repaired one supply in my time and it was pretty straight forward, the
TIP29 was bad and one PASS transistor. So I just replaced all and the TIP29.
>
> Suggestions or links appreciated.

Thank you all for your suggestions  and encouragement.  At this point I am
lost. The symptoms are as such. After acquiring and installing the new
power switch I read through
http://www.repeater-builder.com/astron/astron-repair/astron-repair.html and
tried to deduce what the problem is, but from what I have gleaned from this
information I still have not resolved the isse. What is happening is that I
am showing a solid 13.8vdc +/- on the Voltmeter but as soon as you apply
even nominal load (in this case an 8W LED array) the voltage drops to zero.
>From what I gathered from the aforementioned document I would think the
main filter cap would be the issue but it seems to test fine. I have out of
complete loss for an answer replaced the LM723 and all four 2N3771s...no
go. I am open to suggestions. I probably overlooked something in my reading
or this particular situation was just not addressed.

Several of you offered to help me diagnose this PSU and I had hoped to do
this alone, but so far it hasn't happened. While it has been a good
learning experience I obviously have a ways to go yet and i would
appreciate any assistance ant of you care to offer.

If you would like to help please email me directly so we don't tie up the
lists.
kd5ckp gmail com <kd5ckp at gmail.com> see the QRZ link below if needed

Thank you all again and the list moderators for the off topic bandwidth.

Tim KD5CKP
http://www.qrz.com/db/kd5ckp