Sega SST Boot issue

Hello everyone

I have an issue with SST. It was running normally and suddenly it started to reset itself. After I turned it off and on again, it wouldn't boot up anymore (only GI lights are on, nothing on the DMD and no sound).
The led lights on the MPU board are not turning on at all anymore. The led lights on the power board however are on except the L2 (5v) and L204. I left the pinball off for more than a week and turned it on again. It started to work again and started to reset after awhile (2-5 minutes). After turning off, it didn't boot up anymore The boards have been serviced and should be working but I am still not able to boot it up. Does someone maybe have a tip where I could start looking for faults? Thanks for your help!

#2 4 years ago

RJG

vintageclub

Pinside member

Rapid City, SD

11y 36,650 241

OP
Quoted from Code:
Hello everyone
I have an issue with SST. It was running normally and suddenly it started to reset itself. After I turned it off and on again, it wouldn't boot up anymore (only GI lights are on, nothing on the DMD and no sound).
The led lights on the MPU board are not turning on at all anymore. The led lights on the power board however are on except the L2 (5v) and L204. I left the pinball off for more than a week and turned it on again. It started to work again and started to reset after awhile (2-5 minutes). After turning off, it didn't boot up anymore The boards have been serviced and should be working but I am still not able to boot it up. Does someone maybe have a tip where I could start looking for faults? Thanks for your help!

Those IDC connectors on the board start to get warm and won't allow current to flow efficiently as they warm up during a game. If I were you, I'd turn the game on and wait until it goes into that reset/dead status. Then go into the backbox and jostle each 5v connectors 1 at a time, or turn it off and try unplugging/replugging each one and turning back on. If you find one thats suspect then replace the IDC connectors with a molex-style connector and pins.

#3 4 years ago

TOX

ChrisHibler

Let's see some pictures.
What did the service man do to the boards?
We need the details.
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#4 4 years ago

???

Code

Pinside member

The MPU had a battery leakage. This was however repaired over a year ago and has been working since this issue.
The power board was also checked. Capacitors and a transistor have been changed.
Both were working fine during the service mans test. I am certain that the boards are working as the service man repaired another whitestar board and has been working without any flaws.
IMG_8847 (resized).JPGIMG_8848 (resized).JPGIMG_8849 (resized).JPG

#5 4 years ago

???

Code

Pinside member

I will test the boards in my other Sega pinball. Then we can know for sure if the boards are working correctly

#6 4 years ago

TOX

ChrisHibler

Alkaline corrosion abatement wasn't performed correctly on the board.
Above the battery holder location, you can see where corrosion has invaded the ground trace solder mask. If this wasn't cleaned up properly, I'd have little faith that the rest of the job was done properly.

The switch rows connector should have been removed and replaced and corrosion under it abated.
U213 and U214 were not removed for, at the very least, inspection underneath. Those chips are critical to MPU operation.
SW200 should be removed and inspected.
U206 and U207 are sometimes hit. They communicate with the power/driver board.
The dual row header that connects to the driver board is always a suspect in alkaline corrosion cases. The corrosion drips down on the connector, gets under it, and corrodes the connections, severing the communications with the power/driver board. The game won't boot unless it can talk to the power/driver board.
And finally, the bare copper should either be "tinned" with solder or conformal coated to prevent oxidation and possible further corrosion.

Sorry to be the bearer of bad news. The good news is that the board is entirely repairable still, with the proper expertise.
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#7 4 years ago

TOX

ChrisHibler

At about 30 seconds into this video, you'll see what a proper repair looks like.

--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#8 4 years ago

???

Code

Pinside member

Hey Chris
Thank you very much for the valuable input.
In your opinion, shall I test the board on a different Sega Pinball to determine if it's a definite board fault or shall I get the board repaired again?

#9 4 years ago

TOX

ChrisHibler