Xenon no sound....help appreciated.

TDA2002 is obsolete. You will have better luck looking for TDA2003 which is a replacement but still obsolete from STM. A lot of the STM parts you see on eBay are counterfeit but still work. I have read people say the counterfeit TDA2003 lack short circuit protection like the real ones do but otherwise ok. Not sure what to expect from TDA2002 marked stuff from eBay tho.

There is still a company in Taiwan that make legit good TDA2003 which is a drop in replacement. I have used plenty of them.
http://www.unisonic.com.tw/datasheet/TDA2003.pdf

Have you checked TP4? When sound is triggered and should be playing noise TP4 should start to pulse and be flat 0v when no sound. If you get action on TP4 the CPU is probably running OK.

Then check TP6. When sound is playing you should see ~1 VAC there when sound in progress. If nothing there but you get action at TP4 replace the sound chip.

It is normal to get some display noise to come out the speaker when volume is adjusted high. That means the amplifier and volume control is probably working fine.

TP4 is the VMA. It should be flat 0v when no sound, that is normal. If you get pulsing there when sound would be playing the sound board CPU is running. I don't think it should ever be solid high / 5v.

For TP6 set DMM for lowest range AC volts. Repair book says it should be 0.35vac +/- 1vac when sound is playing and 0vac when no sound. If it never changes from 0v then the sound chip is never making sound. Since the VMA is active when sound should be playing I'd suspect the sound chip or maybe the PIA. With a logic probe you can watch the PIA ports connected to the sound chip (labeled DA0). They should go active when sound should be playing.

The speech board complicates things. An issue on the speech card could mess up the sound board. I don't know what to expect from the software if the speech board is not connected, but I'd assume it would work, so maybe try with the speech card ribbon cable off.

The bally repair book is pretty good for this board. It doesn't talk about the speech board tho. Around page 75.
http://arcarc.xmission.com/Pinball/PDF%20Pinball%20Misc/Pin%20Repair.pdf

AY-3-8910 is obsolete so you may be looking at a donor board or the gray market. Some clones/alternatives where manufactured later and may be easier to find. File made KC89C72 which is drop in replacement until like 2012. Winbond WF19054 is another drop in ready clone. Yamaha YM2149F should work too.

ebay.com link » 3pcs New Kc89c72

REMARK! but at 400+ pcs sold they are probably ok.
ebay.com link » 1pcs Ay 3 8910a Programmable Sound Generator Ic Dip40 New

http://www.arcadechips.com/product_info.php?products_id=154

If you have a donor board with a 6821 PIA on it, maybe try that too in your sound board.

That is nice Marco sells them but that does not change the obsolete status of the part. Obsolete = no longer manufacture . I would guess GI discontinued production 10+ years ago. $14 @ marco vs a used pull for a $1.... I'd rather get 10 used pulls from eBay and take my chances that there that most to all I get will be working.... buts that is me. No gaurantee listed the that Marco will send you a new part. Since you mention the chip was stacked two tall is a common way they are packed in bulk coming Chiina. They might be reselling used pulls too with a 1000% markup.

https://www.aliexpress.com/item/32889808983.html
$6.20 shipped for the 10pcs of the File slot machine clone part. Drop in replacement.