My future spa just suddenly stopped playing sounds.

I've only had it a couple of weeks and don't really know what it's had done to it, but looking at the boards:

There's a new MPU board (no brand name on it anywhere)
all of the caps on the sound board have been replaced.
Solenoid board and lamp driver (and aux lamp driver) look untouched -and test ok
rectifier board is a new replacement board
Displays are LED displays.

It was playing fine and then the sound just went.
The u4 ROM on the soundboard looked very corroded so I have replaced that.
Initally there was no sound after I installed it - so I did the usual thing of reseating all of the connectors:
Firstly I fiddled a bit with J1 on the sound board and the sound came back, but when I closed the headbox up and put the back glass back in, of course there was no sound.
Then I fiddled with J4 on the MPU and the sound came back, So i assumed it was a connector issue at J$ on the MPU, but I only had sound back for 1 game, and the next time I turned it on - no sound.

TP 1 and TP2 on the sound board have the correct voltages.

I'm not sure if the connectors are original or have been repinned.

I reflowed the solder to the headers on the sound board J1 and the mpu J4 but no change - still no sound.

My next plan of attack is to repin the MPU J4 connector and the Sound board J1 connector.

The MPU J4 is end of cable so I'll just do the standard molex pins (I haven't repinned before but it looks fairly straight forward). I've ordered the pins and connectors from Big Daddy as I couldn't find them in Australia (didn't know where to look). Hopefully they will turn up soon.

What I need help from the Pinsiders with is the J1 connector on the soundboard. It's a pass through style connector and I can't find any information on how to repin these. Can someone walk me through it?

668F11A4-E49F-44BB-9A4E-F5EC55EB5EE1 (resized).jpeg

7F7FB372-1934-45E5-BBB4-2ECE813E510F (resized).jpeg

9FAFAB0A-C81F-4233-B3B6-6900C56EACCB (resized).jpeg

Sorry, I should have been clearer. Yes new U4 socket and New U4 Rom chip.

Hi, thanks for the advice. I have done all the simple stuff, voltages are correct, speaker is fine, can hear the humming as the displays cycle. Volume control on the board works fine, there is no volume pot on the door. Board header pins have been resoldered and I have checked continuity of all cables going to the board from their source at the mpu and sdb ( from the outside of the connector pin )

So I have narrowed it down to:
Problem with the sound board
Problem with the MPU
Problem with the Solenoid driver board
Or a poor contact in one of the many connectors that are involved in the sound board.

I plan to swap out each of the boards for a known working one first to rule out a board issue before I attack the repinning of connectors. I’m just waiting on the new sound board to arrive.

However, the advice I have found online is that all header pins and connector pins should be replaced when you are restoring a machine, so I expect that it’s going to be there. I hope it’s not though and swapping out the sound board fixes it. I’ll keep you all posted.

An update, and still haven’t found the problem.

Swapped the as 2518-51 out for a new multi rom board (@barakandl) and the J1 connector seemed to be the issue. The position of the wires made a huge difference and just a small wiggle and the 5v disappeared. ( the onboard LED was very helpful in showing this). So I repinned the J1 connector and it seemed solid. No amount of wiggling of the wires caused any issue.

I put the original soundboard back in, and tried the wiggle test. It seemed fine. Sounded great.

However, after leaving the game on for 10 minutes the sounds stopped.

So what on the board could cause the sounds go after “warming up”.

The pins have been reflowed, it has new caps, and a new eprom.

I’m at a loss, the only similar problem I found on pinside was due to cold solder joints on the pins, but that’s not my problem.

Could any of the chips work when cold but fail when warm?

So I just put the original board back in, as I hadn’t tried it cold after it stopped making sounds last week. But now it’s not working at all. It’s definitely a board issue, but I’m not sure where to look. As I’ve said, new caps, new eprom, new flowed pins. And it was working up until last week, there was definitely an issue with the J1 connector, I wonder if the power cutting in and out to the board has damaged a component.

Any pointers on where to look would be great. Any components on the board you would check/replace.

I’m guessing I’ll have to swap out some of the chips next. Hopefully it’s one of the socketed ones.

There’s no led on the original board.

Yup, I’ve just changed the PIA and it seems to be working now.