Author Topic: Bally S5500 No Sound (Read 5176 times)

mateo107 · « **on:** February 20, 2017, 05:27:33 PM »

Hi Guys,

Thanks for helping tremendously during my "bought sight-unseen" repair process on my 199x Bally S5500 slot machine. I've managed to get it about 95% there. I've struggled through battery issues, grounding out issues, a bad switch, some broken trace wires, but with some patience I've made it almost to the finish line.

Anyway,

This machine had sound, I think, but now it is not playing anything. I've tried turning the potentiometer on the board all the way up and all the way down, still no sound.

I took the potentiometer off the board and tested it with my meter, seems to be working just fine. Re-soldered it back on, and still nothing. I checked the speaker itself and it does work quite well (used another audio source).

I'm trying to chase the speaker wire, but I lose it. Does anyone know where the wire(s) plug into. Are they into the door and then in the main bundle from the door to the backplane? Could there be a chip that's bad on the board, that's causing this?

Thanks kindly for any and all suggestions - at the moment - I'm stumped.

-Matt

Badbaud · « **Reply #1 on:** February 20, 2017, 08:37:17 PM »

The speaker is located on the door, near the bottom left hinge. It should read 8 Ohms with a Ohm meter with one lead removed from the speaker. It could also be the amplifier chip on the board or one of the output capacitors could be broken off of the board.

mateo107 · « **Reply #2 on:** February 21, 2017, 12:03:13 AM »

Thanks. Speaker is good. Any help on which chip is the amplifier chip and or which caps are for sound output?

rokgpsman · « **Reply #3 on:** February 21, 2017, 06:57:46 AM »

The sound amp chips on the mpu board are U61 and U62. The sound circuit output coupling capacitor is C13. Do a good inspection in that area of the mpu board looking for broken parts. If possible, before you start replacing parts on the mpu board I'd confirm the mpu board is where the sound problem is, there are lots of other things that could be causing no sound. Does your machine have a Door I/O board? If so that could be the problem. Also there can be a broken or disconnected wire.

I think the sound goes from the mpu thru the backplane board and out backplane connector J14 pin 12 over to the door i/o if there is one. Maybe the speaker wires get connected to the door i/o, or they may go directly to the backplane board. I'd follow them back and see where they connect. If you have or can get another mpu board to plug into the machine you can find out if it is good or bad.

Badbaud · « **Reply #4 on:** February 21, 2017, 08:51:52 AM »

One other thing I have found fixing sound problems is the center leg of the volume control is broken off of the board.
The long plastic knob on the volume control gets bumped and rips out the center contact.
The volume works sometimes when the leg makes contact, then stops when the center leg is not making contact.

mateo107 · « **Reply #5 on:** February 21, 2017, 11:29:42 AM »

So, more tests, more results.

Tested the speaker with separate input - works fine.
Used a tone generator, unplugged the speaker and traced the wires back to J14 on the backplane. Seems fine. Reseated the whole connector at J14 for good measure.

With the board powered off, tested continuity and resistance on the potentiometer, U61, U62 and C13 and all seem to be within normal levels.

Not sure where to go from here. Would it be worth bypassing the potentiometer as my next step? Replacing the capacitor? Everything "checks out" good, at least, from what I can tell.

rokgpsman · « **Reply #6 on:** February 21, 2017, 12:11:15 PM »

Looks like you have proven it good all the way from the speaker to the backplane board, so maybe the mpu board is the problem. Because it is difficult to inject a signal onto the installed mpu board to figure out where the signal is lost you could try replacing the output audio amp U61 or output cap C13 on the mpu board.

Also, make sure the backplane board does not have any bent or broken pins on the connectors that connect to the mpu board. The sound will enter the backplane board at one of the mpu connector pins, then travel over a board trace to the J14 connector on the backplane board.

And just in case, is there a silly jumper or dipswitch or menu setting somewhere that shuts off the sound? Did the machine ever have sound since you've had it?

rokgpsman · « **Reply #7 on:** February 21, 2017, 01:54:39 PM »

Not entirely sure but I think the sound signal leaves the mpu board at connector P1 pin C3. That mpu connector mates with the Backplane board connector P1-C3. From there the sound travels over a Backplane board trace to J14-12. So you might make sure the backplane is ok between those 2 places. If you inject a tone signal into Backplane P1-C3 you should get sound at the speaker. (don't forget to reconnect the speaker cable to J14)

So, does your machine have a Door I/O board? If so does the speaker connect to it?

If the mpu sound pot looks ok and where it solders to the board is ok I don't know if I'd bypass it. You could attach a wire just upstream from the pot, say on the U62 side/upper leg of the pot, then reinstall the mpu board and then inject the tone signal onto the wire to see if sound gets thru to the speaker. At this point it can be a small injected signal since the main audio amp is right after the volume pot. You will need to set the volume pot to midrange. If the sound does not get thru to speaker then you can move the wire downstream and try again, try to isolate where the signal is lost.

mateo107 · « **Reply #8 on:** February 23, 2017, 05:44:31 PM »

Turns out it WAS the audio amp (5 pin) TDA2002. Replaced with the current model the TDA2003 and sound works like a champ.

Thanks all for your help!

rokgpsman · « **Reply #9 on:** February 23, 2017, 09:14:52 PM »

Good Job on getting it working!

And a thumbs-up to Badbaud, he mentioned the audio amp back in reply #1, so he got there ahead of us.

Badbaud · « **Reply #10 on:** February 23, 2017, 10:38:13 PM »

There is still somebody selling TDA2003's ?
Who. please tell me.
I have been saving ones from scrapped boards because I could not find a supplier.

rokgpsman · « **Reply #11 on:** February 23, 2017, 10:56:50 PM »

Looks like they are available on ebay from many different sellers, new parts (probably old unused stock).

Here's an example:

http://www.ebay.com/itm/NEW-TDA2003-ZIP-5-10W-ST-IC-AUDIO-AMPLIFIER-AMP-INTEGRATED-CIRCUIT-3-PIECES-/222165807614?hash=item33ba1d31fe:g:MdkAAOSwuYVWpnxq

Badbaud · « **Reply #12 on:** February 23, 2017, 11:03:46 PM »

Thanks. Not my favorite store but may be a last resort.

rokgpsman · « **Reply #13 on:** February 23, 2017, 11:08:08 PM »

yep, mouser and jameco type places don't have them anymore, so you gotta go where you have to go.

mateo107 · « **Reply #14 on:** February 24, 2017, 07:49:54 AM »

Yah, was hoping Amazon would have them or a local store would... but I ended up going the eBay route too... mostly because they were close and I'd have them in a day or two. Otherwise, I would've made it to an electronics store nearby to pick some up (at least, I think they'd still have them)...

http://www.ebay.com/itm/2x-TDA2003-Digital-Power-Amplifier-ZIP-5-IC-AUDIO-RADIO-12v-10w-USA-/111130360815?hash=item19dfe2bbef:g:XEwAAOxyP4dTeD-z

rokgpsman · « **Reply #15 on:** February 24, 2017, 09:31:34 AM »

There's a lot of things wrong with ebay but there's also plenty of folks on there that provide stuff that is hard to find elsewhere. just my opinion but I'm ok buying off ebay. I guess it is sorta the walmart of the internet.

Sunrise Side · « **Reply #16 on:** February 24, 2017, 10:29:55 PM »

Can I ask where the location of the audio amp is on the board? I have a board with the same issue i wouldlike to repair . Thank You

Badbaud · « **Reply #17 on:** February 25, 2017, 03:11:02 AM »

Check everything else before you assume it is the Audio amp.

Bad speaker.
Open volume control.
Broken output cap.
Open trace.

Amp is near the lower left corner of the board.

Sunrise Side · « **Reply #18 on:** February 25, 2017, 06:13:33 AM »

Thanks for the tips on the other possible problem areas. I will definitely check those. Thank You!

rokgpsman · « **Reply #19 on:** February 25, 2017, 07:02:39 AM »

Quote from: Sunrise Side on February 24, 2017, 10:29:55 PM

Can I ask where the location of the audio amp is on the board? I have a board with the same issue i wouldlike to repair . Thank You

Look at reply #3 above.

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Author Topic: Bally S5500 No Sound (Read 5176 times)