Cabinet speaker hum?
Anyone ever run into this?
Don't seam to get any sound out of the speaker outside of a bad hum. I can unplug but the speakers up top really have a thin sound with out having this larger speaker working.
Have 13.5 VDC going to speaker. You think it is just a bad speaker? This is for #The Walking Dead Premium. #Stern S.A.M audio board.
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Do you know what the normal voltage is going to the speaker?
I think the ohms reading of the speaker was 63 ohms but I can double check, do you know normal ohms for the speaker?
And the Blocking capacitor You were referring to I am assuming this is on the Power Driver PCB board And if so can you just replace cap or is it more the practice to replace the board?

I couldn’t find a voltage chart for the speaker and since I was seeing a positive and negative symbol on the speaker I set me meter to measure DC voltage. I just checked it again with my meter set to AC voltage and I have 29VAC ( unless I reverse my meter leads at which point nothing) So polarity must be in play to get this voltage.

Is 29VAC About right you think?

Also OHMs on the speaker was 10 ohms on low and 4 ohms on high. It is a upgraded speaker the previous owner put on. Was wired for the high setting, so 4 ohms. the manual that comes with the unit states factory speaker is 8” 4 ohm speaker
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Would you say that 29VAC going to the speaker is the problem. Meaning a board problem?

Hey not resolved yet but I do have it diagnosed. I have dug into the manual and identified what voltages should be where and have done some voltage readings. The CPU sound board is suppose to have -12VDC and a +12VDC along with one +5VDC power coming in from the main power control, which I do have. The CPU sound board then sends the signal to the speakers, two channels one the two top speakers and one for the lower speaker giving me the issue.

Two top speakers work, and when testing for voltage going to those two speakers I get nothing, if there is a constant voltage supply then it most be a lower scale and something that is not of concern. However when testing for DC voltage to bottom speaker I have 13VDC constant and the speaker cone immediately pops out when you plug the wire into the speaker and when you unplug while live you can see a arc, which no speaker I have ever owned, for say a stereo, would do that and I am assuming neither should this.

So the CPU sound board is the culprit and like Wayout was saying probably a capacitor or something in the board. I did get a factory speaker before going through all the tests above for $16 in hopes of a simple repair just to try it out and of course same issue because I am never that lucky

I also, as a back up, ordered a couple of capacitors for the CPU sound board, they were less than a $1 from the place I ordered the speaker from, and was going to get a ESR meter which allows you to test capacitors while in circuit instead of unsoldering to test but after closer inspection of the board the solder joints are so small and the board looks so delicate that I am afraid to attempt.

Talked to two local repair shows, and when they run into problems with these newer boards they send out to Stern for rebuild attempts or possibly have to get a new board all together.

Sent a message to Stern support and they responded saying it does sound bad and to either purchase the board from a local distributor or have them send the board to them. Just messaged them back asking if I can send directly to them or purchase (not sure if they even rebuild) waiting on a response..

Hopefully they can repair the board, if not looks like the board would be $600, although Macro Specialties only seems to have this board for ACDC and Star Trek and I do not see it anywhere else when searching internet. So after this long story I am in a holding pattern and hopefully stern does not make me go through a middle man.

Does he specialize in rebuilding/fixing boards?

I am trying to get an answer from Stern if they can rebuild, they replied back a few minutes ago and said they will not allow me to send the board directly to them or purchase through them, still waiting to hear if they will likely repair my board or just say I need new

Awesome and with out getting weird I love you man!!! LOL

How did you get such a clear pic of the inner works of the board? My manual on this section is not legible and the on line version was no improvement. And you are right it is that chip!!! Take a look at the pics, the good U50 and the bad U51 you just pointed out. The caps didn't look bad (which I know you can still have bad ones that look good) and didn't feel confident that was my problem and hated to de solder and check or try getting an ESR meter that I have never used before but I feel a lot better about this now

I have a factory speaker new that I only plugged in for a second to see if I would get lucky, I probably won't reinstall the Flipper fidelity speaker even though I still show it is good at 4ohms and no short to ground, plus I am wondering if the additional boost you get from the speaker may stress the system.

I am gonna order a few of the chips today and I will solder in, I will give you a update. Its been awhile since I have done this type of soldering so I will get one of the practice boards just to play first before do this.

Can't thank you enough!!

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Oh bye the way the cabinet speaker has been working, I have had this pin for a little over a year, I am 3rd owner and so far this is the only problem I have had with this pin. The guy I bought it from or the original purchaser upgraded this speaker, but the two up top in the back box were factory. Like I said I will just use the factory one.

Thanks again and I will post an update when I finish

I think it could have been the speaker, not familiar with this upgrade but if a speaker is going to make it louder yet run off the factory circuit it has to stress that circuit. I always had kind of a thump sound when I would power this pin up but since unplugging this speaker it does not make that sound. I will be curious when I get the new parts if that sound will remain or if it will be like it is now with that speaker not hooked up. My other pin is silent as it powers up. I always thought that bump or thump when I powered it up was from a transformer but I am thinking it was not and just in the beginning stages of failure.

Should know by Monday when I get the part in. Thanks again for everyone’s help!

Update. All fixed Thanks PinWoofer !! & way out

I bought a practice board to do some soldering first, since I have not done anything this small before: https://www.amazon.com/gp/product/B07MRJKHCQ/ref=ppx_yo_dt_b_asin_title_o02_s00

Was able to get a 10 pack of the amplifier chips for less then $10:https://www.amazon.com/gp/product/B07WSX33DQ/ref=ppx_yo_dt_b_asin_title_o02_s01

Already had a soldering iron but here is the same one I used:https://www.amazon.com/gp/product/B01712N5C4/ref=ppx_yo_dt_b_asin_title_o01_s00

Ordered a no clean solder wick to help remove solder from the holes so I can install the new chip: https://www.amazon.com/gp/product/B0195UVWJ8/ref=ppx_yo_dt_b_asin_title_o01_s00

And now I am up and running. below are some of the final pics. I also notice a huge difference when I power this up now, no to very little noise using the factory speaker (like I said the upgraded one may have been going bad but use to make a very loud thump when I would first power on the pin...I didn't want to risk having the upgraded speaker cause my issue again)

If you are looking to upgrade a speaker use PinWoofer His systems are isolated and wont tax your factory control boards IMO

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