Re: Star Wars Power Supply

Try some freeze spray and see if you can get a reaction from any of the
components.

jwelser@ccwf.cc.utexas.edu wrote:
>
> Hey all,
>
> Here's one from the Twilight Zone.....
>
> My Star Wars power supply has died twice in the past week or so,
> both times with the same symptom....
>
> That Symptom: No +5V. The continuity of all fuses (and
> fuse holders) is good. Tracing back uncovers wierdness with the
> +10.6 VDC unreg. With the connector unplugged from the RA/II board, the
> +10.6 VDC unreg will SLOWLY climb to around +10.6 VDC. When I say SLOWLY,
> I mean over the period of time of about a minute or two. It climbs more
> or less linearly from 0. When I plug the RA/II board in, the +10.6 VDC
> unreg line doesn't get above a volt or so.
>
> This sounded like a leaky cap, so I replaced the big blue cap in
> the power supply. That fixed it....for a little while at least. Now I
> have the same problem again. My only guess would be the bridge rectifier.
> It, however, tests out OK using the "standard" diode test. I suppose a
> possible explanation would be a weak bridge rectifier that can't deliver
> the necessary current to charge up the big blue cap. I also thought it
> might be a problem with some of the connectors, but they look clean and
> check out with good continuity.
>
> So, has anyone run across a "weak" bridge rectifier before? It
> seems to be an odd failure mode. Usually these things either open up or
> short out, but I guess every once in a while they could do something in
> between....
>
> Joe
Received on Mon Aug 16 22:15:57 1999