[TechAssist] Re: Fisher AMP CA-9025 No power
- From: "adam miller" <adamt123@xxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Wed, 19 Sep 2001 11:21:25 -0400
jeff,
i wouldnt recomend jumping this relay just yet. first, do you have a 12Vdc
voltage drop on the coil of the relay? if you do have this drop, then
voltage is at leasted being 'sourced' to it, but not nessasarily 'sinking'
any current, usually there are two ways to activate the relay, one is to
'sink' it by putting it in series with a transisitor(usually on the coll of
NPN) and other side of coil is going to b+, or one side of coil is going to
gnd and other side to collector of PNP or to collector of normal on NPN.
anyway it is very simple to test relay, if u suspect that it is bad, i would
pull it out and just apply voltage, some relays are polarity sensitive, so
be sure to watch out for that and also some have diodes on the
coil.........also check for breaks bettween the solder pads and the big
traces on the power transformers... it is a common problem on fisher
amps.....also you can do another check to see if any kind of protection is
going on, remove the fuses that supply the +/- voltage to the output section
and try to power up, if it works after that then you have a problem in the
output section.......let me know next time about do you have all standby
voltages?
good luck
troy
>From: "Jeff Dougherty" <jeff@xxxxxxxxxxxxxxxxxx>
>Reply-To: techassist@xxxxxxxxxxxxx
>To: "Techsonline" <techassist@xxxxxxxxxxxxx>
>Subject: [TechAssist] Fisher AMP CA-9025 No power
>Date: Tue, 18 Sep 2001 22:19:34 -0400
>
>
>When I press power, the power LED does not light, but power standby does.
>There is no output.
>Q413, Q414 have low resistance, in circuit..there are next to power
>transistors on large heat sink.
>Before I pull these, is this normal? It seems if they were leaky, the fuse
>should open.
>I have no relay click when I press power.
>110vac on relay even when I press power..12vdc on other side.
>Can I jump this relay to confirm the relay is bad?
>Jeff www.9-11-2001tragedy.com
>Help those affected by the NY/PA tragedy:
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>
>
>
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