Slow DMD

[paddythegreek]

Ever since I bought my TOM 10 yrs ago the dmd takes around 10 secs to work. I ve swooped the display,the driver board but it's still around 10 secs with swopped boards. I've put the dmd in other machines and it comes straight on. I got a guy interested in it but the long warm up time is putting him off.
Any ideas. I think the machine came from Portugal before i bought it. Ken

 

[Spandangler]

I don't know Ken but if I wanted a TOM and it took 10 seconds to come on but worked flawlessly and had done the same to you for 10 years I'd buy it anyway. But that's just me

 

[Cryptkeeper]

my roadshow is the same.

 

[Moonraker]

Sounds like it could be slightly low voltage supply to the DMD at switch on. Possibly caused by a little resistance in a fuse holder or an electronic component (just a few to choose from!).

I suppose you could check the switch on voltages as given here:
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Testing_DMD_Controller_Power

 

[paddythegreek]

I Will check it,thanks but it's academic now as the gits changed his mind. Bloody pinballs are like women, you can't live with them and can't live without em. Now sits back and waits for abuse from female members.

 

[*paulb*]

Could it be a grey import blanking circuit (as described in section 4.21.6 of the pinwiki page in Moonraker's post):

4.21.6 Display is "delayed" after turn on
There are cases of import machines incorporating an aftermarket circuit that delays the DMD display from appearing for a fixed amount of time after the game is booted. This was done by some operators so that serial number and location information could not be ween when the machine is powered on, thereby preventing identification of a game and potential sales/operation outside a given geographic area. This circuit will not damage anything but is not standard. More information about this can be found in a rec.games.pinball discussion.

 

[pinballmania]

Agreed. Can't remember what it looks like, but look for non standard circuitry on the cabinet. It isolates the Ac to the dmd psu for a short time until the serial number info has passed.

 

[paddythegreek]

Thanks for the info. I'll look over the weekend

 

[paddythegreek]

I make no apologies for the long post as i figured the more info i give it may well help someone else with the same problem.
This morning i raised the playfield and started looking for anything that didn't look original (as suggested by Andy). I found 2 green wires and 3 different coloured thinner wires coming out of a corner on the Universal power interface assy where the metal had been bent to allow a gap for the wires to project through. I traced the green wires up into the backbox and found the brown wire from J604-8 which runs from the dot matrix controller board to the dmd display had been cut and each end of the green wires was soldered to one end of the cut brown wires.
I unsoldered the green wires and resoldered the brown wire back together then used shrink tubing to secure it.
After making sure each green wire was safe i switched on and Voila, instant dmd.
Switch off and remove securing screws on power interface assy (silver box) then removed base and found a green unit and small beige square assy inside (see pics).The 3 thinner wires are from the beige thingy and were spliced into wires running down the l/h side of the cabinet feeding the coin interface board.I just cut these off as close to the joint as i could. Removed both unwanted bits and put the power interface assy back.
So problem solved and thanks to all for their input. Ken

 

[ronnie63]

Well done on sorting that! Jeez what a length to go to suppress the dmd starting lol

 

[J.C.Rox]

Now @Cryptkeeper can see if RS has the same!