Subaru Outback Forums banner

1 - 11 of 11 Posts

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #1
McIntosh stereo doesn't work... ***Solved***

I've thought this issue was multiple things in the past so I need to start from scratch. 2002 H6 with McIntosh - no sound at all.

How many things are plugged into the back of a McIntosh stereo - i think three: antenna, amp cable, and normal Subaru connector.

Swapped in 3 different McIntosh stereos and none have any sound.
Swapped in another amp and rear speakers (I already know the fronts work). Fuses are good.

I guess I need to test for power to the amp - It's supposed to get 12 volts I assume?

Can I test for an output signal from the headunit to the amp....what kind of voltages are those unamplified signals? Is there any access to the metal pins, those are some tiny round DIN connectors or whatever they're called, not sure I can get a multimeter pin on the pinouts?

Or any other way to test a McIntosh stereo besides plugging it into a car (which I'm not sure is properly functioning to begin with).
 

·
Registered
Joined
·
18,172 Posts
If you've swapped in known working head units and amplifiers, and they didn't work, it would pretty well come down to power or wiring.

The head units all use the same pair of fuses whether regular or McIntosh, but with the McIntosh, the external amplifier is powered through a third 12 V source. Did you check this third supply?

See the fourth page of the attached wiring diagram. Power for the amp is from SBF-8 to a 20 Amp fuse in the relay block (connector B225). That's the relay block under the dash, to the left of the steering column -- it should have six relay sockets and four fuses (see attached relay block diagram). The amp fuse should be the top one of the four.

If the fuse is good (and you can measure 12 V at the socket), then I'd check for the 12 V at the large harness connector (R110) at the amplifier; there should be 12 V at pins 1 and 7.
 

Attachments

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #3
More updated/complete information below...
 

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #4
I can't find anything wrong. At the amp:
Pins 1 & 7 both have 11.20 volts.
Pins 10 & 11 both have continuity to ground.

THREE different McIntosh stereos all act identically.
TWO different amps, using all three stereos with each one, no change.
Any other Subaru stereo and I get sound out of the front two speakers.

I can't verify the amps are coming on or doing anything though. They have power and ground but there are no lights or anything at them.

So - how to test the amps?

When I first install each headunit the LCD flashes "SYS"...I assume just because it was plugged in. Push the ON button and they all operate the same.

* But maybe this SYS message indicates something else?

So:

1. I'm missing something
2. Both amps are bad
3. All three headunits are bad

Amps seem most likely....so how to test/verify they're doing anything....I'm going to pull one apart and see if I can find a fuse in it...
 

·
Registered
Lawn ornament XT
Joined
·
14,366 Posts
AFAIK the McIntosh is making line level signals (1v) for the amp input. You ought to be able to temporarily adapt this to feed a household amp for testing.

Conversely, any line level source (cd player, smartphone, ipod) could be adapted into the amp for tests.

Does the amp get warm when turned on for an hour?
 

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #6
*Solved* finally! Thanks guys for the tips and pin outs! High five!

I disassembled the amp and there's a 25 amp fuse soldered to the board. I assume the other amp will reveal the same.

I'm going to solder wire to it and mount a fuse holder externally on the case.

Questions:
1. Any tips for soldering wire/mounting the external fuse?
2. There's one crusty diode - can I test that via continuity - in one direction right?
3. Should I spray the board down with anything...cleaner...etc?

I'm not fixing the board only to have the fuse blow immediately and have to disassemble it all over again. I'll mount the fuse externally on the side of the case.

It is obvious that being under the seat it not ideal. There is dust and debris galore and one of the diodes appears crusty on each side. I've got kids so he back seat area gets well used.

Owners with amps (and kids LOL) may want to be sure to keep it clean, dry, and dust free under the passengers seat.

Thanks for the help guys, I'm not good with electronics and particularly deficient in audio. Looks like I may finally have this McIntosh system up and running soon finally.
 

·
Registered
Joined
·
18,172 Posts
Was the internal fuse blown? If it was, does that mean that the fuse in the other, replacement amp, is probably blown as well? In other words, was it not a known good amp when it was tried, or could the fuse have blown in it when it was connected to your car?

If you mount an external fuse and it blows, i would imagine you'll have to go inside in any event, unless it's already confirmed that the amp works fine with a new fuse.

Would have to see the board, case, and location of the fuse to address your first question. Can you take photos (including close ups) of the board and post them so we can have a closer look?

Is it the diode itself that's crusty, or just where its wires are soldered to the printed circuit board? If it's the solder, it has to be removed and the diode re-soldered to the board. (The printed circuit under the solder might be corroded.) The diode can be checked for continuity (conduction) or shorts. If you have a digital multi-meter, it probably has a diode check range.

These amps do suffer from moisture, spills etc, and I've seen some that had large areas of the printed circuit board eaten away by salt and soft drink solutions. (Some of these leave conductive material that can short circuits and blow fuses.) If the traces are all intact, the board can be cleaned with a 99+% alcohol -- spray the board liberally flush away any deposits and let it dry. If necessary, a soft(!) brush can be used to loosen dirt/deposits.
 

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #8
It was not a confirmed good amp so I don't know if the car "caused" both or not.

Car was wrecked and I bought it as a totaled salvage vehicle 70,000 miles ago. I rebuilt it, drivers side door needed replaced so could be that the wreck caused it to blow.

The diode is so tiny I can barely tell what's going on, just some fluffy stuff around the ends that connect to the circuit board.

I did solder an external fuse yesterday and got nothing...but I did it rather quick.

I'm going to disassemble the second amp. I'll post pictures of any questions I have, never repaired a board before. My soldering iron doesn't actually de-solder the solder on a circuit board...but it works fine for the solder I have.
 

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #9
Okay - so it's not solved now...GRRRRR

I disassembled the second amp and the fuse was FINE. tested continuity and it's golden.

So - I either have two bad amps or something else is wrong.

How do I test an amp...or proceed to verify it is the amp?

Is there a way to verify that signals are coming from the Headunit (keeping in mind I'm not well versed in electronics)
 

·
Registered
Joined
·
18,172 Posts
Before going into the amp, are you sure there's continuity between the 14 pin amplifier connector (R110) and the speakers?

Based on the wiring diagram, the connections that go from the head unit to the speakers when using a regular radio are different than the connections from the McIntosh amplifier. I wonder if the wiring from the amp to the speakers isn't hooked up. That's why a regular (non-McIntosh) radio seems to work (at least to the front door speakers) but not when a McIntosh is used and the amp is involved.

Page 4 of the wiring diagram shows connector R110. Pins 2 and 8, and pins 3 and 9 connect to the two front door speaker networks. If you have a digital multi-meter, measure the resistance between each pair of pins; there should be continuity, somewhere around 4 Ohms. (What you are looking for is continuity with a fairly low resistance -- if it's hundreds of Ohms or more, the speakers aren't going to work.)

Let's make sure the speakers are being connected back to the amplifier. Then we'll see if there's some way to deal with the amplifier itself and signals from the head unit to the amp.
 

·
Registered
OBW H6 VDC, Tribeca, XT6
Joined
·
12,391 Posts
Discussion Starter #11
Page 4 of the wiring diagram shows connector R110. Pins 2 and 8, and pins 3 and 9 connect to the two front door speaker networks. If you have a digital multi-meter, measure the resistance between each pair of pins; there should be continuity, somewhere around 4 Ohms. (What you are looking for is continuity with a fairly low resistance -- if it's hundreds of Ohms or more, the speakers aren't going to work.)

Let's make sure the speakers are being connected back to the amplifier. Then we'll see if there's some way to deal with the amplifier itself and signals from the head unit to the amp.
copy that. i'll get those checked.

I wonder if the wiring from the amp to the speakers isn't hooked up. That's why a regular (non-McIntosh) radio seems to work (at least to the front door speakers) but not when a McIntosh is used and the amp is involved.
Someone on USMB figured out why the non-McIntosh stereo works fine via scouring the FSM:

There are 4 other outputs from the head unit it appears, and they aren't labeled as speaker outputs but two of the connector codes match up to the front door cords. This could be why the front speakers work.
There are two outputs that appear to end in the dash, perhaps this could be the rear channel and the wiring to the back was not put in at the factory?
 
1 - 11 of 11 Posts
Top