Power but no sound from radio

lumbercis

Moderator
As the title states, my (system10) radio doesnt make any sound. Head unit has power and buttons seem to operate normally. Antenna goes up when you turn it on, but nothing comes out of the speakers, not even static.

What are some likely areas to check?
 

Andy

Member
Check the Amp under the passengers seat, make sure it has has power. All sound goes through it.

Andy
 

TEAMFaint

New member
Did you use the harness with the rca's for sound? or the wired ones?
gotta use the harness with the rca's.
also make sure to hook up your remote turn on wire (blue white on the harness) to blue on the back of the harness of the deck.
remote turn on actually physically turns on your amp.

(this is all assuming you used a metra harness or along that sorts to hook up your after market deck)
 

lumbercis

Moderator
This is a completely stock system we are talking about. I havent had a chance to check the amp yet but will do in the next couple of days and update the thread.

Thanks for the ideas so far guys.
J
 

lumbercis

Moderator
Okay guys, I finally got around to actually getting a voltage tester and testing both plugs with it. Since I've never done electronics troubleshooting before, I could use some help interpreting these results:

X=no red or blue reading at all.

Larger plug:
Top Row:
Wire color: Blue/Y Blue/R G/B Blk Red Pink Aqua
Result: Red X X X X X X
Bottom Row:
Wire color: Blue/Blk Blue/Wht G Brn/W Brn Yel Wht Purple Blue
Result: Red X X Blue Bl X X X X

Smaller plug:
Top row:
Wire Color: Blk Blue Brn Red Pink/blue
Result: Bl Bl Bl Bl wBl (weak, about half as light as normal blue)
Bottom Row:
Wire Color: Grn Yel Red Wht Wht/blk Blue/Red Grey
Result: wBl wBl X Bl Bl Bl Red

Anybody see any problems here?

Thanks
J.
 

lumbercis

Moderator
So the little instruction sheet I got with my voltage tester says that Red=+12V power and Blue=-12V ground, but doesn't mention anything about the weak blue readings I got. Is that maybe the source of the problem? Does that mean it's a wiring issue? Or something to do with the head unit? Anything else I should check?

Thanks
J.
 

alltracst185

New member
First thing i would check and change out is the factory amp under passenger seat..i have one i'm not using if you want ot just pay shipping and it's yours :wink:
 

lumbercis

Moderator
Thanks man! Yeah, PM your paypal and I'll try it out!

I did make one mistake in my initial description. I do get static on some channels. Basically, channels that don't seem to have a radio signal will give me static. If I hit "scan" and wait for it to stop it will stop on a channel and the display will look like it's getting signal (FM1 light will turn on etc.) but there will be no static or sound.

I pulled the head unit out of the console and checked all the connections were tight and checked the connections on the antenna as well.

I did the voltage test on the plug into the head unit as well and got the following:

Top Row
Wire color/voltage light
Pink/Bl Blue
Green Blue
Blue/Red Red
Red Blue
Brn Blue
Blue weakBlue
Black weak Blue

Bottom Row
Blk/red Blue
Wht/Grn Blue
Wht/blk Blue
Wht weakBlue
Red X (no light at all)
Yel weakBlue
Grn weakBlue

Should I be worried about that Red wire with no voltage?
 

Andy

Member
From what I see in the wiring diagram between the head and the amp there are two "red" wires.

One is the +B (12v power to the amp).

The second is labeled "Beep", through which the head triggers the "Beep" sound.
I would not expect to see voltage on this one all the time. (only when the head wants to generate a beep).

From what I see the connector(s) at the head and amp look like

01.**.03.__.__.04.05.06
07.**09.10.11.12.13.14

Where:
"**"'s are not used.
and "__" are not used, due to connector clip.
Color code is in parens.

03 = (Red), +B power
04 = (BR) Mute
05 = (L) FL
06 = (B) FR
09 = (L-R) ACC
11 = (W) SGnd
12 = (Red) Beep
13 = (Y) RL
14 = (G) RR

07 = (B-R) Ant note: 07 and 01 go to the antenna
01 = (P-Y) AMP

10 = (W-B) Gnd (sealed)


I believe the "ACC" is the "low power" trigger to turn the amp on.
And, then it then draws it's "working" power from the +B

So, I think, both of these should have +12 going into the Amp.
Also, make sure both grounds have connectivity to ground.

Note: the amp will have another connector to go to the speakers...
It should be the larger connector.

Hope this helps...

Andy
 
Actually I think the radio gets power from the amp and the beep line might be signal from head unit to amp looking for power? Its been awhile since I have played around with the stereo and the setup in my blue trac isnt working either
 

Andy

Member
the radio gets power from the amp
Appears to be correct, thanks Tim.

The diagram is showing the power coming from the "Cig & Radio" fuse into the Amp on
pin 7 of the connector as "Acc". I would suggest checking the fuse, but the head works, and they appear to be on the same fuse.

I'm was thinking of it working like my Pioneer Head/Amp. Where, the Amp has power to it all the time through a direct wire (a "+B") to the battery (fused). It also has a second wire (an "Acc")from the Head, but the Amp doesn't actually "power up" until it sees voltage on the "Acc" wire from the head. When it does, it then draws its power through the "+B" wire. So, that's why I'm thinking that the "Acc" acts as the trigger to power up the amp.


Studying the diagram some more, maybe the "Acc" just passes through the Amp to the Head and then the "+B" in their diagram is the trigger for the Amp to draw it's power from A 7 & 16 on the Dome fused line (w/a 20 amp fuse vs the 15 amp cig & radio fuse).


I still think the 'Beep" wire is to trigger the "Beep" sound which the System 10 generates. That is a generated tone. If the head generated it, there would be no need for a "Beep" wire.

OK, scanned the diagrams.



This morning I was looking mostly at the connection between "S-8" and "r 5" connectors.

Notice in the "Service Hints", it shows:

A-7, A16 -Ground, Always Approx. 12 volts.
B7 - Ground, Approx 12 volts with ignition on (or ACC position)

The first one is going through the "Dome" fuse. Does your Dome light work?
My want to verify: "A-7, A16 -Ground, Always Approx. 12 volts."
And, the 12 & 13 pins have ground continuity.

Since they show A-7 and A16 as "Always Approx. 12 volts", and the other as "12 volts with ignition on (or ACC position)" this would seem to fit into how I "Think" it works. I don't actually know for certain.


Andy
 

lumbercis

Moderator
Good discussion! I think this the kind of thread that will help others troubleshooting their system 10's in the future.

I'll check the dome light when I get home tonight.

alltracst185 is sending me his spare amp, so we'll see if it may just be a bad amp. It may be because I noticed that on the channels where I get static, even if I turn the volume all the way up, the static itself isn't very loud. So it wouldn't surprise me if it's not being amplified.

One other newb question... where do I look to check/replace fuses for the system 10 and other interior stuff?

Thanks!
J.
 

YerRandO

Member
Not sure if you've seen this old post but it might be relevant, mine fell victim to this.

The system 10 and other Toyota double din head units all suffered from a common
flaw in the past. Toyota cheaped out on the capacitors used in the deck, the caps
went bad slowly, and things like left channel playing softer than right channel
or CD playing softer than tuner started to occur. The fix is not tough, nor does
it have to be expensive. However, if you've never worked with electronics before,
make sure you find an A/V repair place that can do it. The parts cost a matter of
a few bucks, the labor shouldn't be more than $25 or $35. And FWIW, the System 10,
when working right sounds pretty good. It certainly sounds better than spending
$300 on a headunit you don't need. Especially when for $300 you could buy a new
Aussie Dp....but that's another story.

++++++

Perform this at your own risk. You need to get the entire head unit out of
the dash and CAREFULLY open up the CD player. You'll have to take the
entire contents out of the metal shell because the circuit board is on the
bottom. CAREFULLY (there are lots of delicate wires to pop off) remove the
circuit board from the unit - you'll need to unplug several plugs (look at
the way they separate so you'll know how they're supposed to go back on)
and unscrew a heat dissipator at the back right corner (be sure there's
enough thermal compound the back of that dissipator).

The capacitors in question are in a loose group at the back left of the
board. They are red 4.7 mF, 25v capacitors about 3/16 inch in length,
maybe 1/8 in diameter, and there are six of them. It is safe (as I'm sure
the electricity-savvy know - I didn't) to use a larger voltage capacitor (I
used 50v), as long as you can make all six of them fit. I would bother
asking for them at Radio Shack - try a more industrial-type electronics
store, like Shields.
 

lumbercis

Moderator
Bump!

Tried out a known good system 10 amp but unfortunately that wasn't the culprit. Thinking about trying to source an OEM head unit.

I saw a thread on MR2OC about putting later Toyota OEM head units in earlier cars. Has anyone here ever successfully done that? I'd actually love to replace the double din unit with a single din.

J.
 

Brad_91

New member
Hey, I have been having very similar problems. Does yours work on any output? My CD player will only play through the front tweeters, and FM does not work very well at all. From what I remember a few speakers work but not all of them. The cassette player does not work from what I remember. In the next few weeks I am going to try and install another head unit that I have (with an average aftermarket deck) and if that won't work I'm going to try bringing my stock one in to get repaired.
I'll continue to check these posts out, and if I figure anything out I will let you know as well!
 

lumbercis

Moderator
Just to update this thread, I took the car to a local car audio place and the guy there said he thought the head unit was bad... One thing I neglected to test was playing CDs. It actually will play CDs but very softly. You have to crank the volume almost all the way up to get much sound. Didn't really check each speaker in detail, but he said he didn't think it was likely a wiring issue or an issue with the antenna, and since I'd already tried another amp...

This is thread on MR2Oc I mentioned before: http://www.mr2oc.com/showthread.php?t=240774

It looks like our cars use the 15-pin connectors. Anyone know what other Toyota head units use that connector?

Thanks
J.
 

Brad_91

New member
lumbercis":1xy09fpb said:
Just to update this thread, I took the car to a local car audio place and the guy there said he thought the head unit was bad... One thing I neglected to test was playing CDs. It actually will play CDs but very softly. You have to crank the volume almost all the way up to get much sound. Didn't really check each speaker in detail, but he said he didn't think it was likely a wiring issue or an issue with the antenna, and since I'd already tried another amp...
J.

Was he able to repair it or did you just get a new one?? If it is an easy fix I would get it repaired..
 

lumbercis

Moderator
I'm looking for a replacement... he didn't seem inclined to want to repair a stock system.. probably not much money in it for him.

J.
 
The low volume from CD player is a known problem. There are some bad capacitors on the boards in the radio. There was a writeup on which ones, locations and sizes at one point on the board. Dont know if it exists anymore. I just took mine in to an audio repair place and shelled out 300 to have mine fixed (several years ago)
 
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