Can I fix this receiver?

Guest
My friend gave me a Technics SA-GX700 receiver. I wanted it to drive
some fairly cheap outdoor speakers on the deck.

She assured me it worked the last time they used it, but when I set it
up, I get no sound, wither through speakers or headphones.

I can see the graphic EQ responding to the tuner and the CD input.

When I turn the unit on, I get a click (relay?), then about 2 seconds
later another click.

There is a cooling fan on the back that is not running. I'm not sure
if this fan is supposed to run all the time, or just when needed.

I took off the cover, and checked the three fuses I could find.
They're good.

I also disconnected the fan and checked the voltage of the pins that
supply power to the fan: .2 V.
 
I noticed that the second "click" is coming from a component marked
"Type DH2SU 24VDC."

Is this a protection relay?
If so, where do I look upstream for what's tripping it?

I don't have any speakers connected...just headphones.
If I turn the volume to maximum, I can hear a tiny signal in the left
headphone; nothing in the right.
 
Mitch:
Before you tear anything apart you might want to confirm that you have not
inadvertently left a tape monitor switch on.....
or if you only have one set of speakers hooked up make certain that you only
have that one set turned on with the buttons on the front...... if both
sets of speaker ( A & B ) jacks are turned on with only one set hooked up
you will not get any sound.....
and check on the back panel, if there are jacks on the back for PREAMP OUT
and MAIN IN, then you must jumper the outputs to the inputs or there might
be a switch near the jacks that will accomplish that task.
If non of these suggestions help..... try plugging in some headphones.....
sound?
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
-----------------------


<Mitch@hotmail.com> wrote in message
news:dshtvvggpdbtfjs8e7k195an4chl84n662@4ax.com...
My friend gave me a Technics SA-GX700 receiver. I wanted it to drive
some fairly cheap outdoor speakers on the deck.

She assured me it worked the last time they used it, but when I set it
up, I get no sound, wither through speakers or headphones.

I can see the graphic EQ responding to the tuner and the CD input.

When I turn the unit on, I get a click (relay?), then about 2 seconds
later another click.

There is a cooling fan on the back that is not running. I'm not sure
if this fan is supposed to run all the time, or just when needed.

I took off the cover, and checked the three fuses I could find.
They're good.

I also disconnected the fan and checked the voltage of the pins that
supply power to the fan: .2 V.
Click to expand...
 
Mitch:
Yes... this is a protection relay and it is suppose to click to turn on the
speakers a few seconds after power on. I would guess that either a tape
monitor switch has been left on or jumpers are missing on the back if this
receiver has jacks for preamp out and main amp in.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------


<Mitch@hotmail.com> wrote in message
news:mgitvvg8ia3qh7q5mmkmjicf62c27joj5k@4ax.com...
I noticed that the second "click" is coming from a component marked
"Type DH2SU 24VDC."

Is this a protection relay?
If so, where do I look upstream for what's tripping it?

I don't have any speakers connected...just headphones.
If I turn the volume to maximum, I can hear a tiny signal in the left
headphone; nothing in the right.
Click to expand...
 
On Fri, 9 Jan 2004 07:39:26 -0800, "Sofie" <sofie@olypen.com> wrote:


If non of these suggestions help..... try plugging in some headphones.....
sound?
Click to expand...

It's definitely not Tape Monitor, as I switched this off and on
several times.

But there ARE Pre Out / Main In jacks on the back...with no jumpers!

Can I jumper these with plain RCA cables?

I'm waiting eagerly for your reply!
 
Yes, RCA cables are fine.

--
Jammy Harbin
J & J Electronics, Inc
227 S. 4Th St.
Selmer, TN 38375
731-645-3311
<Mitch@hotmail.com> wrote in message
news:gtjtvvcb3cusq41p2n38a91jt0885geotm@4ax.com...
On Fri, 9 Jan 2004 07:39:26 -0800, "Sofie" <sofie@olypen.com> wrote:


If non of these suggestions help..... try plugging in some
headphones.....
sound?


It's definitely not Tape Monitor, as I switched this off and on
several times.

But there ARE Pre Out / Main In jacks on the back...with no jumpers!

Can I jumper these with plain RCA cables?

I'm waiting eagerly for your reply!
Click to expand...
 
YES.... jumper with cables.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
---------------------



<Mitch@hotmail.com> wrote in message
news:gtjtvvcb3cusq41p2n38a91jt0885geotm@4ax.com...
On Fri, 9 Jan 2004 07:39:26 -0800, "Sofie" <sofie@olypen.com> wrote:


If non of these suggestions help..... try plugging in some
headphones.....
sound?


It's definitely not Tape Monitor, as I switched this off and on
several times.

But there ARE Pre Out / Main In jacks on the back...with no jumpers!

Can I jumper these with plain RCA cables?

I'm waiting eagerly for your reply!
Click to expand...
 
FIXED!

Well, wasn't broken. :)
In any case, THANK YOU a thousand times.
 
Good deal, Mitch. BTW...the jumpers usually supplied with receivers like
this are simply a piece of bare wire bent into a 'U' shape which connects
'only' the center pins of the RCA connectors. If--like me--you dislike
'cable clutter' or you need your cables for connecting components; you can
fashion jumpers from a couple of chunks of ten gauge wire. Make sure you
get the bend and spacing accurate, or you will short the signal to ground
(or damage the jacks)...no damage possible, but one or both channels will
not work. It should push straight in with a bit of resistance, but not
short against the outside of the jack.

jak

<Mitch@hotmail.com> wrote in message
news:afntvvofh84dnj07pds8rtaflf0qm7g2so@4ax.com...
FIXED!

Well, wasn't broken. :)
In any case, THANK YOU a thousand times.
Click to expand...
 
On Fri, 9 Jan 2004 13:52:45 -0600, "jakdedert" <jdedert@bellsouth.net>
wrote:

; you can
fashion jumpers from a couple of chunks of ten gauge wire.
Click to expand...
Thanks, I may try that.

One more question. The cooling fan isn't on.
Should it run constantly, or does it turn on and off as needed?
 
Mitch:
The speed of the fan is temperature modulated ..... when you use the amp at
high power levels, it will come on, just make certain that you reconnected
the connector that you removed when you measured the voltage.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


<Mitch@hotmail.com> wrote in message
news:6g3uvvg5toto775g5n7or96vdkb4vggkph@4ax.com...
On Fri, 9 Jan 2004 13:52:45 -0600, "jakdedert" <jdedert@bellsouth.net
wrote:

; you can
fashion jumpers from a couple of chunks of ten gauge wire.

Thanks, I may try that.

One more question. The cooling fan isn't on.
Should it run constantly, or does it turn on and off as needed?
Click to expand...
 
The speed of the fan is temperature modulated ..... when you use the amp at
high power levels, it will come on
Click to expand...
Actually, with a lot of Technics receivers, the fan comes on in response to the
load levels of the output section. If you turn the volume up with nothing
playing through the set input, the fan won't run. But, if you play something
loud on that same input and run it at moderate volume, the fan may come on in
response to the increased demand to the ampilifer ICs. (Don't know of many
Technics receivers that actually used transistors in place of ICs for the
output sections.)

This execution of the cooling fan was a real serious problem with the Technics
SA-DX930. That receiver almost always had a tendency to overheat. - Reinhart
 
Oh, no.

The receiver was working great.
But since the main music source is my PC (CD's, MP3 collection, etc),
I wanted to use the receiver and speakers to monitor my PC audio
signal.

No problem.

However, I also wanted to be able to direct that audio signal to my PC
speakers OR the receiver. So I ran the PC audio signal to a system
selector, and ran one output to the PC speakers, and one output to the
receiver.

Again, no problem. It's been working great.

Today, however, I went to switch the selector to the receiver, and the
receiver quit on me.

I realize now that I shouldn't have been switching it back and forth
while the receiver was turned on!

Thw standby light is on, but when I turn the unit on (and I still get
the two relay clicks, about 2 seconds apart), the display only says
"CD," and all of the other info is blank. If I switch to tuner, it
just has the freq. number, and no other info.

More importantly, the red LED on the volume knob is not on.

I checked (with a multimeter) the three fuses I can see (are there
more?), and they are all good.

Did I ruin the receiver?

Stupid, stupid, stupid! It was working great until I had to put that
dang switchbox in!
 
Brand and model number of the receiver might help.

mz

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


<Mitch@hotmail.com> wrote in message
news:k91o00hordo57lkofg7i4ej5al6l5kf9c0@4ax.com...
Oh, no.

The receiver was working great.
But since the main music source is my PC (CD's, MP3 collection, etc),
I wanted to use the receiver and speakers to monitor my PC audio
signal.

No problem.

However, I also wanted to be able to direct that audio signal to my PC
speakers OR the receiver. So I ran the PC audio signal to a system
selector, and ran one output to the PC speakers, and one output to the
receiver.

Again, no problem. It's been working great.

Today, however, I went to switch the selector to the receiver, and the
receiver quit on me.

I realize now that I shouldn't have been switching it back and forth
while the receiver was turned on!

Thw standby light is on, but when I turn the unit on (and I still get
the two relay clicks, about 2 seconds apart), the display only says
"CD," and all of the other info is blank. If I switch to tuner, it
just has the freq. number, and no other info.

More importantly, the red LED on the volume knob is not on.

I checked (with a multimeter) the three fuses I can see (are there
more?), and they are all good.

Did I ruin the receiver?

Stupid, stupid, stupid! It was working great until I had to put that
dang switchbox in!
Click to expand...
 
If you're lucky, maybe just a blown fuse or other fusible device. Obviously
a part of the power supply is dead, but there is a distinct chance, given
your description, that an output IC is blown with a resulting blown fuse(or
2). Technics models generally use proprietary, expensive output devices.

Mark Z.



--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


<Mitch@hotmail.com> wrote in message
news:jm7q00pskdpm7o7q9iii8vm4hacok2uboc@4ax.com...
Brand and model number of the receiver might help.

mz


Technics SA-GX700
Click to expand...
 
There are three fuses visible near the power supply.
Would there be additional fuses under the boards?

Would shorting the CD inputs have caused this?
 
Mitch:
No, no other fuses are under the boards.
No, shorting any of the inputs will NOT cause failures.....
.....but, shorting the speaker wires or hooking up too
many speakers can cause immediate failures, most of
the time more serious and more expensive to repair
than just a blown fuse.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


<Mitch@hotmail.com> wrote in message
news:j2cq00tt1ncc57475c4og9i4p83soq8f31@4ax.com...
There are three fuses visible near the power supply.
Would there be additional fuses under the boards?

Would shorting the CD inputs have caused this?
Click to expand...
 
....but, shorting the speaker wires or hooking up too
many speakers can cause immediate failures,
Click to expand...
I'm pretty sure there was no speaker shorts.
The unit was working, then suddenly it wasn't.
 
welcome to the world ..... things break..... even new things.
------------------------


<Mitch@hotmail.com> wrote in message
....but, shorting the speaker wires or hooking up too
many speakers can cause immediate failures,
I'm pretty sure there was no speaker shorts.

The unit was working, then suddenly it wasn't.
..
Click to expand...
..
..
 
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