Author Topic: Board AS-2979-1 (Read 2723 times)

filounet · « **on:** June 01, 2018, 10:15:34 AM »

Hi,

I have two machines that do not work because of AS-2979-1 cards
I tested with a card that works and machines work
I also tested the memories and are ok

I rang all the points of both cards and it works
Do you have any idea of the problem?

In advance thank you for you help and have a nice day
:thank_you:Philippe

filounet · « **Reply #1 on:** June 01, 2018, 10:28:47 AM »

Precision by plugging the cards this indicates as code 1 or 7 on the slot machine

Amechanic · « **Reply #2 on:** June 01, 2018, 11:13:30 AM »

Ok let me get this straight.. You have two machines that will work if you install a known good Ram board.. You have tested the Ram chips from the bad boards and they all work.. That pretty much narrows it down to the 3 soldered on ICâ€™s U3, U4, U5 on the Ram Board.

filounet · « **Reply #3 on:** June 01, 2018, 11:54:45 AM »

Ok so how can I test the 3 ICs?

Amechanic · « **Reply #4 on:** June 01, 2018, 12:55:22 PM »

That Iâ€™m not sure.. Badbaud might know how, but he has a board tester too. I donâ€™t think all three of these IC are still available for sale. I know that Badbaud works at K-Lar and I think he has all the parts to repair them there.

Jim · « **Reply #5 on:** June 01, 2018, 01:26:16 PM »

I'm going to step out on a limb here, I think your two connectors are defective, replace them, and I think you will be in business. the only problems I have ever seen with that board were the connectors.

Jim

filounet · « **Reply #6 on:** June 01, 2018, 01:54:38 PM »

Ok thanks for your return
Are you talking about J1 / J2 or U1 / U2?

Amechanic · « **Reply #7 on:** June 01, 2018, 02:06:06 PM »

Heâ€™s referring to the edge board connectors. See the yellow arrows on my pic.

Trisail · « **Reply #8 on:** June 01, 2018, 02:56:22 PM »

If you have tested the Ram chips from the bad boards in the good board and they work. The connectors may be hard to find. The other 3 IC's are available. If you can solder, hit the pins on the J1 & J2 connectors and possibly some of the other devices. If soldering is not something you do, I can replace the 3 chips on both the PCB's. I can test them to see if they are good 1st. I won't be able to test the complete board. I did not see any of the PCB's on eBay. Good luck.

Amechanic · « **Reply #9 on:** June 01, 2018, 04:35:36 PM »

The edge connectors are available on EBay. I never could find all three of the soldered on IC Chips. Do you have any information on where to buy them??

Badbaud · « **Reply #10 on:** June 01, 2018, 04:58:37 PM »

I have the connectors, IC's, plus the header pins for the MPU board.The OP contacted me about buying a working RAM board then never emailed me back after I replied.
Mouse drop, I'm outta here.

Trisail · « **Reply #11 on:** June 01, 2018, 05:09:51 PM »

Amechanic. If I read the chip numbers right from the pic, U3 74LS30 U4 74166 and U5 74LS27 then they are at Mouser and most other vendors like that. eBay has them too. The 74166 is harder to find (TTL) but the 74LS166 (LS) is out there a lot.
74LS30 8 Input Nand Gate
74166 8 Bit Parrallel In/Serial Out Register
74LS27 Triple 3 Input Nor Gate

Any idea on the manufacturer on the headers?

GOS · « **Reply #12 on:** June 02, 2018, 06:10:14 AM »

ebay 162789762379

filounet · « **Reply #13 on:** June 03, 2018, 03:16:25 AM »

Hi,

The connectors are changed but the card still does not work so it must be one of the 3 ICs that is dead
Have a nice day.

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Badbaud · « **Reply #14 on:** June 03, 2018, 06:19:31 AM »

It could be bad RAM sockets.

Amechanic · « **Reply #15 on:** June 03, 2018, 07:15:45 AM »

Quote from: Badbaud on June 03, 2018, 06:19:31 AM

It could be bad RAM sockets.

So true 🤔 I forgot that Bally used those cheap sockets in there slots and pinballs.

filounet · « **Reply #16 on:** June 03, 2018, 09:36:49 AM »

I warmed the welds before changing the ram sockets and one of the two cards works perfectly so thanks to your advice I have two machines out of 4 that work again

A big thank-you
Philippe

:

Amechanic · « **Reply #17 on:** June 03, 2018, 09:59:02 AM »

Itâ€™s not just the solder joint, but the inside connections of the sockets that fail. They loose the spring pressure on the legs of the ram chips. The old style socket only make contact on one side. The newer style is on both sides of the legs.

Badbaud · « **Reply #18 on:** June 03, 2018, 02:03:00 PM »

If you pull out RAM chip and the legs look dull and not shiny then the DC current of the battery has caused a electro-chemical reaction between the IC and the socket.The socket must be replaced.With those old, original, Bally sockets you can pry the plastic housing off of the socket to expose all of the pins.Then desolder the pins, clean the holes out, buy a AMP double wipe IC socket to replace the corroded ones.

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Author Topic: Board AS-2979-1 (Read 2723 times)