"JR" wrote in message
ups.com...

JR wrote:
Arfa Daily wrote:
wrote in message
oups.com...
Hello, i have a problem with a 3801 denon receiver, ..I bought this
receiver from a guy on the internet, said to be in exellent shape,
when
it arrived, i plugged it in and it will not do anything, no display,
no
standby light, no click when you hit power switch nothing. I have
checked all 7 fuses on the receiver with an ohm meter, they are all
ok.
checked voltage where power cord plugs into board, shows 120 volts,
if
you unplug receiver and checked switched outlet on back of receiver,
the outles show open with ohm meter, unplug yellow and white wire on
transformer to board and now switched outlets are no longer reading
open....does this sound like a power transformer, any way to test?


I don't understand your assertion that the switched outlet reads "open"
with
an ohm meter, then doesn't when the white / yellow lead is unplugged.
Are
you sure you don't mean that you read a short, or at least a low
reading,
when the plug is in, and then an open when it is unplugged ? That
situation
works, as the back panel socket, will be connected in parallel with the
power transformer primary, which is itself switched via a relay. The
fact
that you do read this low value ( I believe ) would indicate that the
primary of the main tx is ok. As the seller said that the unit was ok,
I
would suspect that it might have taken a knock in transport, and you
should
be looking for fractured print on the power input board, particularly
where
any pins from the transformers are connected. I have seen this many
times.
Examine all print around the power input and transformers very
carefully
with a magnifying glass if necessary. I'm willing to bet you will find
your
problem quickly, if you know what you are looking for.






well i have looked it over some more...still havent found much...looked
for fractured print, no luck yet. I did get the dmm back out, to check
voltages...not getting volatge anywhere on the board exept where the
power cord it plugging into board, checked for voltage at the 2 main
fuses..nothing, checked for voltage on every wire on power transformer,
nothing there either

Thanks in advance
Arfa


if i unplug the yellow and white wires from transformer, i then have
voltage at main fuses, plug the connector back in, no voltage at fuses,
also there is 2 red and 1 black wires on transformer...checking between
the red and black shows shorted, the guy i bought it from said he heard
a pop when it quit, and he supposedly replaced fuses....


Ah, then it's not quite as straightforward as you originally implied. I got
the impression that the guy who sold it was saying that it was working when
it left him. I am not liking the sound of popping coming from it. I can make
no sense of the voltage readings you appear to be getting. The system is
straightforward enough if it's the model I think it is. As far as I
remember, there is a standby supply which powers the system micro, and
provides a supply for a relay, which is driven by a power on signal from
said micro. The relay switches power to the primary of the main power
transformer. It is quite common for the thermal fuse in the primary of the
main power transformer to fail, but the symptoms of that are that the unit
powers on, in as much as the relay will click, but nothing else happens, no
display, no sound, nothing. You need to determine if the standby supply is
established, and if not, why not. The incoming power lead should be
connected almost directly to the standby tx primary.

Arfa