(Topic ID: 193192)

Doctor Who Light Matrix Problem

By Boozter

2 years ago

Topic Stats

  • 9 posts
  • 4 Pinsiders participating
  • Latest reply 2 years ago by Boozter
  • Topic is favorited by 1 Pinsider


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lamp_matrix (resized).JPG

#1 2 years ago


My doctor Who has a problem with a light in the speaker panel. The light of doctor 2 is blinking constantly. I don't know what is causing this problem and would really like to fix it.

I made a short youtube clip which shows the problem: http://tinyurl.com/ydhpr238

Hope someone can help!

Thanks in advance!

#2 2 years ago

Is that an LED in that socket or an incandescent? Could be ghosting.

Move the lamp to another socket. See if it travels.

#3 2 years ago

Its an incandescent. It makes no difference if i move the light. It stays at the 2nd doctor.

#4 2 years ago

Darn... this is one of those transistor things. Sorry, my electronics kung-fu is weak <head in shame>.


#5 2 years ago

go into lamp test, and see I found any other bulbs light up when that bulb is selected, OR it lights up when other bulbs are selected. Could be a diode issue.

#6 2 years ago

Went to test it. Turned the machine on and now doctor 2 isnt working anymore. Speakerpanel and playfield. Both stopped working.

Yesterday i fixed a GI row that had its fuse blown. J120 & J121 where mixed and that was causing the problem for my GI it seemed.

But after that i recorded the video with the doctor 2. And over night it stopped working...

When testing lamps on the playfield the hang on insert also lights up with the extra ball outlane. I wonder if this problem is connected with the doctor 2 problem

#7 2 years ago

Okay, so i tested some more and there must be a issue with a diode or a problem with the board. Doctor 2 on the speakerpanel was working again playfield doctor 2 is not.

On every single lamp there is another one blinking. I checked everything under the playfield and it all looks fine. No broken wires or diodes.

I checked it the lamp matrix and attached image is what i found out. Row 2 was perfect. Every other row had double lights. Row 4 and 5 where exeptions to this.

Row 4 No.14 lighted No.84
Row 5 No.15 lighted No.25 after this every other lighted column 3.

So i think my problem lies in column 3 but i don't have a clue where too look next. I disconnected the 5x3 but the problem stays.

Does this mean i now have to desolder and check the diodes in column 3? What about the 5x3 board. How can i test that?

I hope someone can point me in the right direction.

Thanks in advance!

lamp_matrix (resized).JPG

#8 2 years ago

Those are controlled lamps not GI looks like a possible transistor problem (had this on a a Saga Batman) or matrix chip on the CPU.

#9 2 years ago

Thanks all! For your help and tips. I measured the transistors and one gave me nothing. Since repairing boards is out of my league. Im taking my board to the pinball repair store and have it looked after.

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