MP Chassis' 82/70 Rev. C (Smack Down)

[Loneliness]

Problem: I have a MP Chassis on an 82/70 Rev. C machine that when you turn the machine on you get nothing "Black out". So I hit the Chassis with a Pin Fork, Bam! Power, so it runs Scores Etc Correctly then when the Games over, Shutdown is Normal, now when you reissue the Said lane, Same Deal You have to Whack it with a Pin Fork (or Other Object Foot, pin, Wrench whatever)
... So I’m looking for Ideas, Comments and Such on what you did to Fix Said Problem

I have an Answer; I’m just curious what the others have done…

Marshall - Colorado

[TheGMan143]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Just to state the obvious, it's probably going to be a sticking contact in a relay, or a bad solder joint / broken wire (open circuit) somewhere in the chassis.

Checking the connectors leading to the chassis would be the first logical move.

Swapping the board (and cleaning the connector) to see if the problem moves (to isolate it to the board or the chassis itself) would be the second logical move.

Not knowing much about the MP, I would probably start looking at the cardedge connector first, then work outward across the mother board to see if there are any broken / cold solder joints that may have cracked.

If the problem moves with the board, follow the above procedure above on the card to see if there's anything loose... not highly likely, but it's worth a look anyway.

[felix]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

If shutdown is normal..I'd rule out b.e. relay

When wacking the chassis with a motor crank ( I like to hit it gentley behind the two oll's

[Andrew]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

If it just shows it's problem when it's trying to turn on, then I would suspect a bad M relay with a weak coil.

Whacking could cause it to click on (and it stays there because even a very weak magnetic field will hold the armature on).

??
Andrew.

[JimDorsin]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

I agree with Andrew....probably the M relay.

[Lafarge..]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Yep bad M relay or socket.

[Loneliness]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Not the M Relay in this Case, But Nice Guess... Keep Guessing... Will Post the Answer in the Next Couple of Days...

[Lafarge..]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Did you check the socket that M relay plugs into. If it is not the problem I would again check for somthing in the c1 c2 plgs as to somthing not making a good connection. When you Hit this with a pin do you see any sparks like somthing is loose or a a stuck relay. if not can you do it in the dark and see if you see anything light up when this happens.

[AMFDOCTOR]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Bad connection in one of the C-1 pins.

AMF DOCTOR
The doctor makes house calls.

[JimDorsin]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Could also be C2-A.

[8270_Wang]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

T4 transformer supplies voltage for BE relay and M1 relay in the MP chassi.

Wang

[Andrew]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

And if that T4 tranny was not outputing high engough voltage, I guess it could be not quite enough to pull the relays on without a 'kick'. Nice theory Wang.

[cabber]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Does the chassis also start on impact of a bowlingball ? That way the bowlers can turn on the lane themselves, quite handy ! [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[Loneliness]

Re: MP Chassis' 82/70 Rev. C (Smack Down)

Alot of Good Ideas, but the Winner was AC Lines H, AA, KK were the Cause. Changed the Pins and Thats all she Wrote... No more Stress Release at least on this Machine