New used SC-901... no sound

Post by **Volvo4251** » 29 Feb 2012, 12:16

Hi all,

Today I received the SC-901 radio I just bought off of eBay. I plugged it in (external amp cord and all), yet there is ZERO sound. It is picking up FM fine (the ST light is on), reading the song names and everything.

Again to reiterate, I do have the external amp (it's an 850 Platinum) so I know the radio is compatible. Is there something I've done wrong or some setting the radio is in that is preventing it from producing sound? Maybe the radio I bought is bad (even though it was advertised as completely working)?

Please, any help is much appreciated. Thank you!

Post by **rspi** » 29 Feb 2012, 13:34

Unplug the amp. The radio itself has 100 watts so it will sound good without the amp. If you hear no sound ofter that, return it.

Post by **Volvo4251** » 29 Feb 2012, 13:42

Unplugged the amp cord, still no sound... What could be wrong?

Post by **JRL** » 29 Feb 2012, 15:58

You have to stop listening to this guy, he constantly posts bad and incorrect info
An SC900 and 901 has NO internal amp and must use an external amp
It was designed to use the underseat 4 x 50 w amp I'm not sure if the 850R amp that goes behind the dash is compatable or not (or the amp or the radio just may be bad)
Did you try a CD?

Post by **BEJinFbk** » 29 Feb 2012, 18:47

There are several things to consider here.
As stated, the SC-900/901's do NOT have internal amplication
for the 4 corners and must be used with an external amplifier.
( They do have a 1 x 25w amp for the Dolby center channel, but
if you haven't got the center speaker or Dolby module, no biggie ).

The unit should work with any of the various factory optional 4 channel
OEM amps in 800 and 70 series Volvos using the 6 pin DIN cable ( that plugs
into the connector on the back of the HU marked AMP ) and the correct
speaker bypass adapter cable. Just because it says PREMIUM on the radio,
there's no guarantee that you have an external amp.

If you are hooked up with the OEM amp, you'll have the 6 pin DIN
cable and the "B" connector at the HU will only have one lead and many
empty contact spaces. Should look like this:

: SC-901 rear - while connected sm.jpg (35.47 KiB) Viewed 4657 times

This is the AMP connection:

: SC-901 AMP Connector.jpg (46.89 KiB) Viewed 4657 times

Post by **Volvo4251** » 29 Feb 2012, 20:30

I have all of those plugs except for the middle "Dolby" one and the green socket. Again, the Platinum's did come with the external amp! I do have it!

Post by **BEJinFbk** » 29 Feb 2012, 23:24

Just checking -
Ya never know what those crazy Swedes will build!
So, if you're confirming that the "B" plug only has the
one lead, that tells us that the speaker bypass cable is there.

Next troubleshooting step - Double check the amp.
What was the original HU and does it still work in this car?
Swap it back in and confirm everything works.

Post by **Volvo4251** » 01 Mar 2012, 02:47

The old HU was an SC-816. I replaced it because it lost its FM reception. However the old HU works fine (AM, Cassette, and CD) once I plug it back in. The amp is definitely working. I'm starting to think I just bought a heap of junk off of eBay...

Post by **Volvo4251** » 01 Mar 2012, 11:16

--UPDATE--

I took my car into the dealership for it's regular oil change this morning, and asked them to look at the radio as well. They worked their magic and now everything works brilliantly! Case closed.

Post by **matthew1** » 01 Mar 2012, 13:57

What did they do?