Interesting Noise problem...

My Mk2 is having an electrical noise, kind of a buzzing through the speakers. It only happens in the car, so I was thinking a bad ground somewhere. Because it doesn't change pitch as I hit the gas, I know it's not alternator whine. The buzz gets louder as I turn the empeg volume up (but gets masked out as the music gets louder). Oddly enough, the buzzing stops once I put the player into pause. During play and during pause, the drive activity meter is at "white" for both modes.

What changes between play and pause that would make the buzz only happen during play? The drives spin? But wouldn't that make the drive meter change? Could it be the fan causing this? Is the fan smart enough to know if the player is paused or playing? But if the cause is the player itself, why does the buzz only happen in the car and not in my mlord dock?

2 drives, 64mb ram card, led's, fan controller.

VERIFIED: It's the player, not the car. I just popped my backup into the car and had no noise. But why would it only happen in car?

My friend had a similar problem recently, although not the same as yours. You could hear a ton of faint noise through the rear channels at bootup and when music was playing low, but you wouldn't be able to hear when loud.

I took the harness off the sled and noted that the ground pin for the rear channels wasn't clicked all the way into the harness adapter. Clicked it back in and there has been no noise ever since.

Perhaps the same thing is happening to you, but on the empeg's harness plug?

I had the same identical problem in one of my cars. Noisy on bootup and rear channel buzz/static at low volume. Never chased it down because I assumed it was in my wiring. However, I recently sold the car and when I removed my Empeg and replaced it with an Alpine head unit, the noise dissapeared completely, even though the wiring was the same. Basically, I used the same power, ground, memory and RCA connectors on the Empeg and the replacement Alpine. I'll check the sled wiring on the removed Empeg and reply here if I find a faulty ground.

Good idea...

I'm looking at my connector on the empeg, and I see some of the pins don't "stick out" as much as the others.. maybe spending so much time in a dock has some of the "barbs" losing their elastisity? I tried playing with a paperclip to see if I could get them to stick out more, but wasn't having any luck. Do I pull from the back side? Maybe the paperclip needs to be replaced with a better tool...

If any of the pins are having a poor contact with the wires inside, do I need a special crimping tool? Can I just "push" the wires towards the back of the case? I don't want to break this thing.

I doubt it's the connector on the back of the empeg.

What is more likely is that there is an electrical fault in the box: bad sound like you are describing implies a poor earth somewhere. You seem to have a lot of problems with this player: is this the one that had all the mods done to it? I am beginning to question the quality of the work you have had done.

I would suggest you dismantle the unit and remove the main board. I would then make sure your memory board is 100% insulated from the case. Clean the case screw studs and the points where they come in contact with the board on the main board. When you re-assemble it, make sure that the screws are properly tensioned/torqued to ensure good contact to the case. You should tighten the screws until they first resist turning ("finger tight") and then turn them just 1/6th of a turn further.

I found that the screw at the rear of the board near the RCA connectors can occasionally come loose, and has caused odd sound problems (alternator whine, crackle, etc.). This one is either lathered with thread lock (can eventually cause a poor contact) or has none at all (comes loose and a bad contact occurs).

There is also a resistor near the RCAs which occasionally goes bad leading to crackle on the front channels, which just needs re-soldering to restore the sound. It's either R73 or R74, which are 0 ohm links to ground, mounted near the RCA turrets at the back of the board.

Wow! That's great information.
These kind of 'tid-bits' would be great to have compiled into one 'tune-up' thread for easy access/reference.

I love (the people on) this BBS!

Thanks so much Rob! I'll pop this thing open and take a look when I have time not to rush it. You have a PM too..

Have I?

Can you give more detail on where to find R73/R74? I have the problem that *only* the front sled RCA connection has a problem; the rear sled and empeg-internal connnections are fine.

The front left crackles in and out quietly but the left sounds normal. I'm picking that R73, R74 are left and right channels and i have only one with a problem?

With the case open, the drives removed, and looking at the rear connector to the rear left (display closest to you), You will see the two white headers for the wiring to the main connector.

In front of the left connector (nearest the case wall), there are three rows of resistors.

R73 (left channel ground link) is the second in from the left, on the row closest to the white connector. It is marked "000".

R74 (right channel ground link) is the last resistor of five on the right, next to a capacitor, on the third row from the white connector. It is also marked "000".

I have no way to photograph these, sorry. I would recommend you measure the resistance between the ground sheath on the RCAs and the case first, and if you dive in with the soldering iron, then BEWARE that you have identified the problem AND the correct components.

Thanks for your information, guys ToolPeg is back in business! I inspected and found that it was actually some of the other resistors close to those ones. 3 of the 4 (sled) channels had this issue, the inbuild ones had no problems. After resoldering the surface mounts down it is all good again. I have taken a photo and added the components that died on mine incase its useful for anyone else, with markers to the R73/R74 as talked about above.

[image]
http://empegbbs.com/ubbthreads/download.php?Number=285130
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How did you determine that those 3 resistors had a problem? Was it physically obvious(detached solder, etc) or did you run some kind of test on them?

thanks

I actually got a pair of headphones with the ground line grounded, and went testing with the 'live' wire around the resistor network in that area. with some line tracing i traced back the signal to the point the signal sounded crackly, and then just replaced the surface mount resistors! Thankfully it was the final stage output resistors, cause otherwise it woulda been too complex for me to fix probably.

Wasn't visibly obvious, tho the solder did look a little 'dry' didn't check the actual resistors cause the work lab has a stack of replacements (thanks www.energyintellect.com) so I just replaced em.