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Dr who expander Not working

carl lawrence

carl lawrence

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10 Years
Joined
Jul 31, 2011
Messages
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Location
Sandbach
switched on dr who after it has been stood for about 6 months and was greeted with the factory reset . Batteries are mounted off the board and was using lithium batteries ,so I have no battery leakage. So installed new batteries and setting etc and started play game for a test and that’s when I noticed the expander not working , so put it in test and it still didn’t work . I disconnect the motor,which was nice an easy as it is connected with scotch block , so I then lashed up 12v to the motor to see if it moves and yes it does . The gearbox and motor are working perfectly. Looking at the Bi directional board on the machine and J2-1 and pin 4 are both reading 20v with the game switched on , that can’t be right ? .Tip 107s and 102s read ok ,so now i am a bit stumped !
 
20V are strange indeed as the board should be supplied with 12V. If the drivers are Ok it should be U1. you can check pins 5-4 and 7-6, they should be driven inverse, i.e. 5 more positive then 4 and 6 more positive than 7. That should create either +12V or -12V to the motor.
 
drhex said:
20V are strange indeed as the board should be supplied with 12V. If the drivers are Ok it should be U1. you can check pins 5-4 and 7-6, they should be driven inverse, i.e. 5 more positive then 4 and 6 more positive than 7. That should create either +12V or -12V to the motor.
Click to expand...
Yep I agree as 20v is strange but IMG_1886.jpeg
The wording says 20v but the drawing says 12v :hmm:
 
This dr who does have a Rottendog cpu unfortunately .
So had the driver board out and checked the tip 102s and they check Ok so will check the U1 @drhex !
So I turn my attention to the motor board pinwik says it could be diode D8 or D9 so unsolder one leg off to check and there are Ok ,next up the cap at C2 so unsolder that and wipe under the cap and refitted and the expander moved up and down and back up and then stopped working again . So unsolder it again and noticed one of the trace is missing so I am need to order a new cap and do some type of repair for the missing trace .
 
Keep in mind (what has not been mentioned) - you can not test the time expander without:
a: the glass being on
b: the door closed.
c: the balls in the trough (I could be wrong on this one!)

Did you take out your CPU board?

I seem to remember that the switch on the glass on the top left needs to be jammed with some cardboard if you want to test the motor (see point A).

I once had a call out for this very thing not working and all it was the microswitches metal part popped off.....
 
Pick Holder said:
Keep in mind (what has not been mentioned) - you can not test the time expander without:
a: the glass being on
b: the door closed.
c: the balls in the trough (I could be wrong on this one!)

Did you take out your CPU board?

I seem to remember that the switch on the glass on the top left needs to be jammed with some cardboard if you want to test the motor (see point A).

I once had a call out for this very thing not working and all it was the microswitches metal part popped off.....
Click to expand...
I fitted mirror side blades a good few years ago and I didn’t want to drill the blades so that switch is taped up .that was my first port of call to check that the switch was still closed :thumbs:
 
Pick Holder said:
Keep in mind (what has not been mentioned) - you can not test the time expander without:
a: the glass being on
b: the door closed.
c: the balls in the trough (I could be wrong on this one!)

Did you take out your CPU board?

I seem to remember that the switch on the glass on the top left needs to be jammed with some cardboard if you want to test the motor (see point A).

I once had a call out for this very thing not working and all it was the microswitches metal part popped off.....
Click to expand...
Or with the glass off put the game in expander test, pull the coin door switch to enable power and put both hands on the flippers (no need to worry about glass being on, the coin door being closed or having balls in the game). It will then cycle through the expander test. As previously stated, leaving the playfield in an upright position will confirm if the issue is with the gearbox. They can be a bit intermittent when they first fail but having the playfield in the upright position takes the weight off the gearbox allowing it to operate without slipping.

carl lawrence said:
I disconnect the wires from the motor and added 12v straight to the motor and it moves up and perfectly
Click to expand...
Was the playfield in the down position or left upright to give you access to the motor?
 
Moonraker said:
Or with the glass off put the game in expander test, pull the coin door switch to enable power and put both hands on the flippers (no need to worry about glass being on, the coin door being closed or having balls in the game). It will then cycle through the expander test. As previously stated, leaving the playfield in an upright position will confirm if the issue is with the gearbox. They can be a bit intermittent when they first fail but having the playfield in the upright position takes the weight off the gearbox allowing it to operate without slipping.


Was the playfield in the down position or left upright to give you access to the motor?
Click to expand...
When I temporarily put 12v to the motor , yes the playfield was up ,and it indeed it moved very quickly with no weight to slow it down . Looking at my the motor and gearbox it does look that it has been repaired in the past as it is not a sealed unit anymore .
I have ordered a new cap so hopefully that will arrive in a few days and when it does I will sort out the missing trace on the boardimage.jpg
As it should look like this pi takes from pinwik

IMG_1888.png
 
I read that it just smooths the voltage out and wasn’t needed put I wasn’t shore .I will do this tomorrow now after work and see what happens :thumbs:
 
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