Porsche Forum Australia

996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

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3 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Leading reported evidence

Check amp - nothing much

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
I suspected a bad ground somewhere, so I pulled the CDR22 out and checked the amp - nothing much that I could detect.
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996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

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Leading evidence: 'Check amp - nothing much' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check amp - nothing much' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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1 matching discussions · 3 captured posts examined · 1 partial discussions

Compare 3 other evidence results

Replace with faders, doesn't

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Stays there with FM or CD, doesn't change with faders, doesn't change with revs.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Replace with revs

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Stays there with FM or CD, doesn't change with faders, doesn't change with revs.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Use standard rca connectors so it's a little hard

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Of course it doesn't use standard RCA connectors so it's a little hard to narrow down which one is at fault.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Frequently discussed actions (4)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check amp - nothing much

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
I suspected a bad ground somewhere, so I pulled the CDR22 out and checked the amp - nothing much that I could detect.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Replace with faders, doesn't

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Stays there with FM or CD, doesn't change with faders, doesn't change with revs.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Replace with revs

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Stays there with FM or CD, doesn't change with faders, doesn't change with revs.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

Use standard rca connectors so it's a little hard

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
Of course it doesn't use standard RCA connectors so it's a little hard to narrow down which one is at fault.
Original post Read captured discussion
996: Stereo constantly hums when on (CDR22, Hifi/Nokia amp)

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Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

3 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Porsche Forum Australia: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T135432Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

So for about a month now, when I turn on my radio (CDR22) there's a constant low humming from the speakers. Stays there with FM or CD, doesn't change with faders, doesn't change with revs. Goes away entirely if the stereo is off. I suspected a bad ground somewhere, so I pulled the CDR22 out and checked the amp - nothing much that I could detect. Of course it doesn't use standard RCA connectors so it's a little hard to narrow down which one is at fault. Don't suppose this has happened to anyone else? Or is there anyone in Melbourne who's upgraded their car and might have a spare head and/or amp that I can temporarily swap in to try and diagnose the source of the problem? I've got about 4 old head units and same amount of aftermarket amps in the shed I could install, but I kind of like the old school aesthetic of the oem unit.

POST 2Original post

I'm going through the same thing with a customers car at the moment. The problem appears to be in the head unit. James at Soundlabs is checking it out, I'll let you know how I go.

POST 3 / ORIGINAL POSTEROriginal post

Yep, was the head unit. I bought an adapter from ebay that would allow connection of RCAs to the Nokia amp, hooked up a spare ancient kenwood unit and bingo - no more humming. I did like the stock look, but the new/old unit has bluetooth and USB at least.

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