This is going to be a little difficult to explain so bare with me. I'm working on a Stern Wild Fyre. I've replaced all the headers and connectors. All displays work except one. I've moved it from player 2 to player 4 and the problem remains on the display.

The display works fine except two segments come on when they shouldn't. Looks like when segment G lights segments D and E also come on (but not as bright). This occurs on all digits. But the real strange thing is when it lights "4" segments D and E don't light.

1 and 2 light fine
3 lights but segments D and E glow.
4 light fine (and D and E don't glow???)
5 lights but segment E glows
6 lights fine
7 lights fine
8 lights fine
9 light but segment E glows

Could this be a short in the glass or somewhere on the board?

If something is shorted on segment G then why wouldn't the 4 not glow segments D and E?

Anyone ever seen this problem?

segment (resized).PNG

The segments work - just work too much

Thanks

Segment G seems to work OK. The transistor wouldn't cause the other transistors to energize would it?

Perhaps I change Q16 and Q17 for segments D and E.

I'll let you know how it turns out.

Thanks

Bob

I found something interesting - Trying to decide which transistors to change I checked continuity from the transistors to the decoder. I found the base of Q16 and Q17 are shorted. Therefore decoder pins 12 and 13 are also showing short.

Could the problem be in the decoder rather than a transistor?

Thanks

Bob

I just pulled up the base of Q17 and decoder pins 12 and 13 still show a short. I think the decoder is shorted.

I just replaced the decoder with a new chip socket. But I think you're right - I'll replace the transistors as well. Better safe than sorry.

It's getting late so I'll finish tomorrow. I'll let you know how it turns out.

Thanks for your help.

Bob

Thanks zacaj, I followed your advise and replaced the transistors, plugged in a new decoder and it tests fine now.

All displays are working great.

Thanks for your help.

Bob