Bizhub 423 - Constant hissing / static from fax speaker

[Fritzy]

The Bizhub 423 I'm working on has a constant hissing / static noise coming from the fax speaker. The noise starts as soon as the system boots up and the initial 'Ready to copy' screen comes up. The noise is very faint, but is audible from 15 feet away in a quiet room. If I put my finger on the speaker it gets quieter, so it is definitely the source of the noise.

I have the Line Monitor Sound Fax setting turned OFF, and the send and receive volumes set to zero (see attached photo). The noise also persists even when the sub power switch on the control panel is turned OFF.

Any thoughts on what I can do to quiet the speaker? I'm considering unplugging it, but if there is a better option, please let me know.

Thanks!

[Hansoon]

Re: Bizhub 423 - Constant hissing / static from fax speaker

I had once one doing this and only replacing the faxboard cured the problem.

Hans

[emujo2]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Put the machine into fax mode and touch the off hook button. Does the hissing noise change to what you would expect with a audible dial tone, or is it the same. Does the fax work? What happens if you deinstall or isolate the fax? E

[Fritzy]

Re: Bizhub 423 - Constant hissing / static from fax speaker

I had once one doing this and only replacing the faxboard cured the problem.

Hans

Good idea - I forgot I had another fax board to try. However, even with this new board I hear the same noise.

Put the machine into fax mode and touch the off hook button. Does the hissing noise change to what you would expect with a audible dial tone, or is it the same. Does the fax work? What happens if you deinstall or isolate the fax? E

I tried off-hook and on-hook, makes a click sound but then the same noise is present. The fax does work, but has send/receive errors about 10% of the time. I also tried unplugging the phone line, but the noise remains.

I disconnected the USB cable and gray multi-wire cable from the fax board and the sound goes away! (but so does the fax capability ).

[emujo2]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Not sure if you were aware of this, but KM made a special 2 wire fax line for this. The 4 wire caused some issues. Also, are you 100% sure this is an analog fax line and not digital or VOIP? E

[Fritzy]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Not sure if you were aware of this, but KM made a special 2 wire fax line for this. The 4 wire caused some issues. Also, are you 100% sure this is an analog fax line and not digital or VOIP? E

Thanks for the additional information. The noise is present even when there is no fax line attached. However, out of curiosity, I did try attaching a 2-wire fax line and it still makes the same noise.

I am using a VOIP line. An analog POTS line isn't an option here, so I'm aware that there will be faxing challenges due to this.

[allan]

Re: Bizhub 423 - Constant hissing / static from fax speaker

What happens if you initialize the fax function?

[femaster]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Is the ferrite choke attached to the wire harness for the fax board? Not sure if this would help with static noise, as the chokes are designed to help eliminate RF noise, but who knows.

[Synthohol]

Re: Bizhub 423 - Constant hissing / static from fax speaker

fwiw, check the neutral to ground at the wall socket. if more than half a volt id find another power source.
also is it right under a fluorescent light or wireless repeater?
ive seen cell phones when in use near the machine cause speaker noise. that was a ricoh but still.

[blackcat4866]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Me? I'd just unplug the speaker and call it a day. =^..^=

[allan]

Re: Bizhub 423 - Constant hissing / static from fax speaker

There should be a soft switch for the monitor function.

[KeviM]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Me? I'd just unplug the speaker and call it a day. =^..^=

If all else failed that's what I would do as well 😁

[KeviM]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Sounds like 1 of 3 things

1) try a firmware update and hope it corrects it
2) replaced the fax/line board or repair it. Might have a damaged solenoid
3) maybe try a POTS filter on the fax line before replacing the board

All the best friend

[Fritzy]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Thanks for all the additional replies! I took a bit of a Bizhub-break over the holidays so I'm just seeing these now. Here are a some responses to your suggestions:

What happens if you initialize the fax function?

I haven't tried that yet. I just recently got the fax function to mostly-work. I'm hesitant to reset everything now since I'm not 100% sure what settings I changed and I suspect initializing will un-do everything I've done so far.

Is the ferrite choke attached to the wire harness for the fax board? Not sure if this would help with static noise, as the chokes are designed to help eliminate RF noise, but who knows.

Good suggestion. Yes, the ferrite choke is attached to the wire harness for the fax board. I had a couple clip-on ferrite chokes, so I tried adding one to the USB cable as well, but it made no difference. Still the same noise

fwiw, check the neutral to ground at the wall socket. if more than half a volt id find another power source.
also is it right under a fluorescent light or wireless repeater?
ive seen cell phones when in use near the machine cause speaker noise. that was a ricoh but still.

I will check the line voltage - another good suggestion. Lights are LED. I unplugged everything else in the room - including a WiFi access point that I thought might be the culprit, but no difference. same static noise.

Sounds like 1 of 3 things

1) try a firmware update and hope it corrects it
2) replaced the fax/line board or repair it. Might have a damaged solenoid
3) maybe try a POTS filter on the fax line before replacing the board

All the best friend

1. I'm at the most current firmware (as far as I know). I don't have access to all the KM support documentation/firmwares website, so I can't research every firmware patch that might be related to fax.
2. I tried another fax board I purchased on eBay - exactly same result with the noise.
3. Will need to try to find a filter. I used to have some DSL-line filters, maybe I'll dig one of those up and see if there is any change.

Me? I'd just unplug the speaker and call it a day. =^..^=

If all else failed that's what I would do as well 😁

Yup. That's where I'm at. While it irks me that I can't figure out what is causing the noise and solve it, I decided to punt and added a 'Fax Monitor' button that connects/disconnects the speaker. Works great for those times when you want to monitor the FAX tones, and eliminates all static noise when disengaged (see attached).

There should be a soft switch for the monitor function.

I'll look into this, but for now the fax monitor button I added is achieving the needed result.

Thanks again to you all for taking the time to address the issue. If I make any additional discoveries as to the root cause of the issue (and resolution), I will let you know!

[blackcat4866]

Re: Bizhub 423 - Constant hissing / static from fax speaker

Nice touch. Even a label. =^..^=