Photo: pinballphotos
  1. » Forum
  2. » Tech
  3. » Tech: Alpha-numeric
  4. » Data East Blanking question
(Topic ID: 150976)

Data East Blanking question

By johnwartjr

8 years ago



Topic Stats

You

Linked Games

No games have been linked to this topic.

    0
    0
    0
    #1 8 years ago
    OP
     
    JWJ

    johnwartjr

    That Pinball Place

    US Columbus, IN

    12y 77,400 6,479 14

    I am working on a DE CPU that has what I believe is a blanking problem.

    Specifically, when you power the game down, it sends a pulse through every solenoid, lamp and the displays show a little garbage.

    It operates fine, and plays fine. It appears to have taken a hit to the blanking circuit at some point.

    It would not boot initially, I found a bad 7406, 7408 and 7402 and replaced all 3. Now, it boots and everything functions correctly during game play.

    I've gone through the blanking circuit using a logic probe on the ICs and made sure they operate according to the appropriate truth table for the IC. But haven't found the problem yet.

    Anyone seen this before?

    2 weeks later
    0
    0
    0
    #2 8 years ago
     
    EOJ

    silverball0

    Inactive member

    CA Deroche, BC

    10y 39,150 436 10 8

    Hi John, seems I have the exact opposite on my game, upon turning on the playfield flashers, laserkick coming on and stay on along with the last digits of both displays with all segments at full brightness until the game boots up. Not sure yet whats causing this.

    3 weeks later
    0
    0
    0
    #3 8 years ago
     
    EOJ

    silverball0

    Inactive member

    CA Deroche, BC

    10y 39,150 436 10 8

    Hi John, well I finally solved my blanking issue, found that the problem in the blanking generator section of the board. I found the 2n-4437 and the lm 555 bad.

    Reply

    Wanna join the discussion? Please sign in to reply to this topic.

    Hey there! Welcome to Pinside!

    Donate to Pinside

    Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!

    This page was printed from https://pinside.com/pinball/forum/topic/data-east-blanking-question and we tried optimising it for printing. Some page elements may have been deliberately hidden.

    Scan the QR code on the left to jump to the URL this document was printed from.