S+ won't boot

[Nurbo]

Hello,
I have an S + that won't start anymore.

The machine had been stored for a long time, the battery had exploded and acid had leaked out.

The 2 cards were cleaned with vinegar and then dried (I have already done this dozens of times).
Before and after pictures posted.

The machine worked for 2 days, then nothing.
The power supply is working, the fluorescent tubes are working and the reels are powered because there is resistance when I touch them.
However, none of the button lights come on and there is nothing on the display.
I tried by holding down the white test button for several seconds, reset the key, closing the door, absolutely nothing happened.

Here's a video of what happens on startup: https://www.youtube.com/watch?v=c7diA3FEshY

[Stayouttadabunker]

It could possibly be the fuse is burned out from shorted circuitry or the display panel is burned out....even a bad pin on the power harness going to the motherboard.

Check out those three fuses 6amp, 8amp, and 6amp from top to bottom....quick blow fuses only.

Can you try something Nurbo?

Press the small "Service Coin" button on the coin-in optics and see if the reels will spin if you press the "Spin" button on the deck.

If the reels spin, then there's a problem with corroded circuitry traces on either the MPU or motherboard of the floor from battery leakage.

[Nurbo]

Thank you for your answer

I tried and absolutely nothing happened. Not a noise, not a light, nothing ... The 3 fuses of the power supply are ok (tested with a multimeter)

On the motherboard at the bottom of the machine I redid several soldering: all the resistors, the 8-pin chip, the power supply connector.

On the MPU I also redone the soldering: power connector, large diode between the transformer and the battery, the resistors to the right of the battery...

But still nothing, and I don't have a spare mpu or motherboard, I can't test.

[Stayouttadabunker]

Hmm...too bad you can't swap parts with another cabinet nearby?

Try to find out what's bad?

Is there solder both on top and bottom of the C1 [24c04] chip on the MB?

One leg looks like it lost a lot of solder when you heated up the legs.

[Nurbo]

On the right side.

[Stayouttadabunker]

Yes...I did get a chance to see it in your video.

Can you wiggle the power connector on the MB?

Wiggle by moving the top of wire harness above the connector...don't grab the white Molex housing.

See if you can get the display lights to come on?

There could be an oxidized pin causing voltage loss.

Right now, all you have is the denomination lamp on....which is on a different fuse line.

[Nurbo]

After each soldering I checked the tracks with a multimeter. There seems to be little soldering but the continuity is there.

Ok, i'll test to move the molex connector.

I will also look on the documentation for the voltage that must supply the machine's bottom motherboard and I will check if it is ok

[Nurbo]

My last tests were to see if the mpu was receiving power.

At the power output (on the right at the bottom of the body) I measure 24v, so it's ok.

I managed to do an assembly with cable to check if the mpu transformer was functional. I have 24 vac input and 9 vac per output line
I know that the mpu has power.

I noticed that the GAME PROM seemed "floating" in its socket, can the symptom on my machine correspond to poor contact between the GAME PROM and the socket?

[Stayouttadabunker]

On your schematics, look for the pins that supply power to the display panel and check the connector for the correct power voltages other than the denom lamp.

I don't know why your display isn't lighting up the leds.
If you turn the jackpot reset key, will it show if you get into accounting mode?

[Nurbo]

Ok, I'm going to measure the voltages coming into the display panel.

Turning the reset key does absolutely nothing.

[Nurbo]

Hello,

Here we go, the machine is working again.

It was just the backplane board that had been damaged by battery acid.
I didn't find the cut track, I'll have to test track by track, something I hadn't done yet.