(Topic ID: 141667)

Data East LW3 F7 fuse DMD issue

By jjnascar

5 years ago


Topic Heartbeat

Topic Stats

  • 11 posts
  • 4 Pinsiders participating
  • Latest reply 6 months ago by trueno92
  • Topic is favorited by 1 Pinsider

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#1 5 years ago

Hey everyone,

I'm going through an issue with a LW3 pin.

I just rebuilt the HV section, CN1 and the GI connector and keep it consistently shorts the F7 fuse when connected to the DMD display.

Any help on this one is appreciated.

Thanks
John

#2 5 years ago

Can you post a picture of the front and back of the power supply board?
Also, can you post all the part locations that you had replaced?
Do you know what voltages were missing before you rebuilt the power supply?

#3 5 years ago

Thanks for responding, I'll post some photos tonight, but I wanted to give a little background info on the issue.

When I received this unit the DMD did not power, half of the backbox was lit, and the lights on the playfield were pulsing.

After opening the backbox, I noticed the GI cable was burned, The CN1 connector was burned and had pin 12 cut and they soldered the ground to the back of the power supply.

I have since pinned new connectors and replaced the cn1 wafer on the PS.

Here's a list of all of the items I've replaced on the PS:

C9
C6
C1
C4
D2
C3
D3
D7
C2
C8
C10
C11
C6
C7
R17
D10
D9
D11
TR1
TR2
D6
TR3
TR4
C14
C15
R16

I'll test the DMD connector tonight and will post my voltages.

When the DMD displays go bad do they typically short out the PS?

#4 5 years ago

Not normally. Usually something on the power supply just gives out.

#5 5 years ago

Mainly looking for pictures to see if I can help notice any part in the wrong direction and if there is something else to look at that you may have not noticed.

If you leave the DMD unplugged and the fuse still blows out, then for sure the problem is only on the power supply.

#6 5 years ago

As a datapoint. I was also having issues with F7 on my Data East JP machine. I was not seeing proper HV levels at the DMD or at CN1. I chose to simply replace the PS board vs rebuild. I swapped out the board today and successfully revived my machine's DMD. Seemed to be a cheap solution - $97 from Rottendog.

https://pinside.com/pinball/forum/topic/jurassic-park-dmd-repair-suggestions#post-2745988

Good luck!

#7 5 years ago

Sorry for the delay guys,

I managed to repair the fuse blowing issue by reseating all connections and soldering all header pins on the PS.

I also tested the DMD connector;

1 - -160
2 - -148
3 - Key
4 - Ground
5 - Ground
6 - 5V
7 - 12V
8 - 68V

Before, I wasn't getting any power on pin 8, I changed R15 and power came back on that end.

I still have no DMD power; but the pin 8 voltage is restored.

I've read that pin 1 should be -110 and 2 should be -98...with a 12v separation between the two.

I'm not sure if my voltages are too low.

any help is appreciated.

#8 5 years ago

-160 and -148 volts are too far out of spec.

#9 5 years ago

Thanks for the advice --

I just finished checking:

TR4
TR2
D10
D8
D7
R9
R10
R13
C11

I changed R10, because it had an erratic reading...when I pulled it off the board, it read fine.

I put a new resistor in and metered it and it was jumping all over the place.

The other components tested well, except for the zener diodes (D10,D8) as i'm not really sure how to test those diodes.

Thanks,
John

2 months later
#10 5 years ago

Hey John, not sure where you ended up this issue.

I revisited my old DE PS board today (I had replaced with a Rottendog board). My DMD was out, with F7 fuse blowing immediately at start-up.

Turned out my issue was with D5. It was cracked in half. I replaced the 1N4004 and popped the old board back into my machine. Fired right up without a hiccup!

I noticed D5 was not on your list of devices checked or replaced.

5 years later
#11 6 months ago

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