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How can I post quicker so we can respond faster?
"Mark D. Zacharias" wrote in message ...
I'm going to digest this for a bit and will post back later.
Meanwhile, if you're posting through Google, they only add posts once or
twice a day.
Mark Z.
"ampapa" wrote in message
om...
Mark,
I spoke with my friend this afternonn and this was a refurb from the
factory his sister used to work for a Sony call center, but until
recently the receiver was working fine. He was having a on/off issue,
no lightning strike.
I mistyped earlier the 2 IC's that looked like they were replaced are
IC1205 and IC1501 as well as D1207 and D1206. I tested the diodes with
my DMM it has a diode test and they appear to be O.K. (tested one
direction then flipped leads). I'm not sure how to test the IC's?
I took some readings on the 2 IC's (IC1025 and IC1501) and was getting
.25v on leg 1 on both and 0v on the other legs. I also checked IC1206
and here is how it layed out, definitely out of wack...
8 - 1.6v
7 - 1.25v
6 - 6.76v
5 - 0
4 - .35
3 - 1.83
2 - 2.37
1 - 13.53
I wasn't sure what to test on IC1201 did you want me to look at the
reset pin 90 for 5v?
My biggest understanding issue is how do I determine the flow on the
schematic?
"This repair is going nowhere fast. It would be nice to have another
digital
board to sub."
My posts take forever to show up on the forum is there a way to speed
it up??? As far as another board I don't think I can find one? do you
know anyone selling them, cost, etc.
AJM,
"Mark D. Zacharias" wrote in message
...
P.S.
If there's any history on this that I should know, now is definitely the
time to say. For example if there was a lightning strike involved.
Mark Z.
"Mark D. Zacharias" wrote in message
...
I'd say that's close enough. You're going to have to see that the "5V"
line makes it to the microprocessor, and at this point you're going to
have to evaluate the reset line to the micro. Should toggle from ground
to
5V when you plug in the cord.
Mark Z.
"ampapa" wrote in message
m...
I've got 3 readings at the transistor Q1205, the center leg 13.53 and
the 2 other legs 6.79 and 6.21 respectively. I think this is wrong,
the schematic shows the "base" at 6.5v?
"Mark D. Zacharias" wrote in message
...
Well, you need to check the standby voltages on the digital board.
Q1205
appears to be a 5 volt source.
Mark Z.
"ampapa" wrote in message
m...
The "standby transformer" is that T902 on the schematic?
I've got 13.5V on the header that leads to the "Digital" board.
"Mark D. Zacharias" wrote in message
...
Measure from point 12V with respect to ground. I suspect your
standby
transformer is bad.
Mark Z.
"ampapa" wrote in message
om...
No click when I push the power button and I do have my voltmeter
set
to A/C.
By looking at the schematic am I correct that the transformer
should
be seeing appx. 110v? or should I be looking for some other
voltage
being delivered to the transformer?
Also, in order for the A/C board to "enable" the turn-on relay
by
the
on/off switch then I should be seeing voltage coming back from
the
"Digital" board correct? I see the header that leads to the
"Digital"
board has 4 legs, GND, 12V, P_OFF and P.RY. Are these
designations
specific to the industry as to what they represent?
Thanks for the help,
"Mark D. Zacharias" wrote in message
...
If all the fuses are OK, then the power transformer probably
isn't
getting
voltage from the turn-on relay. Does it click when you press
the
Power
button? CNV902 gets no AC voltage to speak of til this relay
fires. (I
assume your voltmeter is set to measure AC voltage)
Mark Z.
"ampapa" wrote in message
om...
Sorry if this is a double post.
Mark, are you saying there might be a fuse literaly
underneath a
circuit board and not necessarily hidden from view by a
circuit
board?
I checked about 5 or 6 fuses in this thing and all checked
fine.
My biggest problem is that when I read the schematic I can't
tell if
the transformer is supposed to be getting 110v from the A/C
board on
CNV902? If it is then I can trace it from there. That's my
real
dilema.
The schematic can be found here
(http://www.eserviceinfo.com/index.php?what=search2).
Thanks,
"Mark D. Zacharias" wrote in message
...
These models often have fuses sort of hidden under a circuit
board
attached
to the transformer. If these fuses are blown you probably
have
a
blown
amp
channel. Sometimes just the output transistors for a given
channel
are
bad,
sometimes there are other small parts bad. Occasionally a
circuit
mod
is
required to lessen the bias at startup.
Mark Z.
"ampapa" wrote in message
om...
First off I'd like to say, "Hello." to the group. I hope I
can
gain
some knowledge from the group's collective input.
I have a Sony STR-DE635 stereo receiver that will not turn
on
and
I
would like to investigate into maybe seeing if I can
repair
it. I
found a set of schematics on this site which I believe
will
definitely
help.(http://www.eserviceinfo.com/index.php?what=search2)
I'm guessing but I think that the problem is related to
the
power
supply? On p.13 of this .PDF manual it has an A/C and D/C
schematic,
this receiver has a seperate board for each. I probed the
A/C
board
and found that it has voltage out to the "Digital" board
of a
little
over 12 volts but when I try to test the pins on CNV902 I
thought
I
should be getting appx. 110 A/C but only get appx. 2?
CNV902
is a
simple 2 wire connector leading directly to a transformer.
My common sense is telling me that why would I need a
transformaer
the size of Kansas for only 2 volts A/C? So, I'm guessing
this
might
have something to do with it? I could be in left field due
to
my
lack
of knowledge and inexperience, that's why I'm hoping you
guy's/girl's
can shed some light.
Thanks for any suggestions or hints you can provide.
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