data east power supply

drwicket

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So I have looked at everything that I can think of and everything looks fine but I am still not able to get any power to the MPU board. I am beginning to think that my power supply is bad. Is there any way for me to check this to make sure this is the cause before I decide to replace it. Also does anyone of anyone in Nebraska that does pinball repair. I think it might be something simple that I am missing but I think I need a fresh set of eyes on it.

If anyone can help me out that would be great.


THANKS!
 
If you have a meter, the board is marked. See if you have power going to the board and off.

If power to the board but not off, easy to pull fuses and check with a meter, be sure the fuse holders have plenty of tension and are soldered on tight. Easy to check the bridge rectifier if it is shorted or open between two legs.
LTG :)
 
I took the power supply board off and inspected the back and don't see any cold saulder points. I also checked all the fuse clips and all of them look good. I checked the bridge rectifier and am getting 26.9 DC and 21 AC. Is it possible that some of the connectors are bad and that's why I'm not getting any power to that board?

Also 5W130VRJ resistor gets very hot when the game is on. Any idea what that means?

This thing is really starting to piss me off :p
 
If you've covered this, sorry I missed it, but I'm not clear if you have measured for 5v at the test points on the CPU. If you get nothing there, have you measured for 5v at the actual connectors coming into the CPU and going out of the power supply?
 
I checked the voltages coming out of the power supply at CN1 and all the voltages are correct based off of what they are saying in the repair guide.

I checked the loops next to the battery pack and I am not getting 5V I am getting 594 on a DC meter.

On CN17 the 3 gray hot wires I am also getting 594 on a DC meter.
On our other LW3 we are getting 4.8 DC volts on these gray wires.

I just need to know if I need to replace something so I can get this thing running. I have had it for several weeks now and I am dieing to get to the restoration of the playfield and the rest of the cabinet but dont want to touch anything until it is at least running.

Desperately need some help. I found a few people in town here that do pinball repair but they are charging upwards of $55 - $75 an hour to do it so I want to only use that as a last resort.
 
Okay, let's try to narrow this down further.

On the PS, CN1 is the power in, so it sounds like you are getting power into the PS and it is correct.

Here's what I'm interpreting you are reading:

-At CN17 on the CPU, pins 4-6, you are reading 594.

-At the 5v test point on the CPU you are reading 594.

Additional info we need:

-What are you reading for the +5v out of the PS at CN6, pins 7-10 (grey wires)?

-What are you reading at the 5v test point on the PS?

-When you are getting readings of 594, what range is your meter set? Or is it an autoranging meter?

-Test everything under load, i.e. with the connectors connected.
 
At the 5v test on the PS I am getting - eratic readings all over the place. It won't stay still.

At CN6 pins 7-10 I am getting - eratic readings nothing staying consistent all high voltage dc readings.

I am using an auto ranging digital multi meter.
I am testing everything under load with the connecters connected.
 
Okay, sounds like the problem is on the PS and not a connector since you are seeing the same goofy readings at the test point. As long as you are getting normal readings for the other voltages (12v and high voltages), it may only be a component on the 5v side.

I don't remember, are the display and sound working correctly? Have you verified the other voltages on the PS?
 
Nothing is working. All I am getting is general illumination. No sound.
 
Okay, if +5v is out, sound and display won't work either because they need it.

Check the following:
- Output from the bridge rectifier in the backbox that is connected to the big capacitor.
- The +12v output at the PS test point.

If these are fine, you then need to test the 2N6057 transistor on the PS that is located on the big heatsink (using the diode test mode on your DMM).

It would also be a good idea to use your DMM in diode mode and check the bridge rectifier on the PS.
 
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When I had checked the bridge rectifier I was getting 26.9 dc and 21 ac. I will check the 2n6057 transistor tonight and see what it says.
 
When I had checked the bridge rectifier I was getting 26.9 dc and 21 ac. I will check the 2n6057 transistor tonight and see what it says.

I take it that is the rectifier on the PS? If so, I think that sounds about right.

Have you checked the rectifier in the backbox by the big blue cap?
 
There are 2 down there by the big blue capacitor and on those I got 17.9 dc / 14.2 ac on one and on the other i got 40.7dc and 29 ac on the other.
 
There are 2 down there by the big blue capacitor and on those I got 17.9 dc / 14.2 ac on one and on the other i got 40.7dc and 29 ac on the other.

Off the top of my head, that sounds right. I think all indications are pointing towards the 2N6057 (or something else in the 5v circuit.)
 
Ok when I took off the 2N6057 underneath there were 3 wires (c) gray (e) white (b) yellow here is what I got when I tested them

cb - -13.04 DC
ec - 13.04 DC
eb - 9.44 DC
 
I don't know where my brain has been. The most likely problem is capacitor C2, the little 100 uF 25v cap below and right of the big heat sink. This little guy gets hot from the heatsink and fails.

But you also should check the 2N6057 with the power off and use the diode test mode on your meter. You'll put one lead on the metal part of the transistor (C) and the other end on one of the two pins (B and E). You should read between .4 and .6 on your meter (it may be between 400 and 600 depending on your meter.)

Some testing info here:
http://www.elexp.com/t_test.htm
http://www.kpsec.freeuk.com/components/tran.htm

If the 6057 checks okay, then you need to check the capacitors, specifically C2.
 
First off I want to thank you so much for helping me trouble shoot!! I had to go out and buy a multi meter that could test a diode so I will be checking all of this tonight. I will post results as soon as I take them.
 
Took as many readings as I could think of. Let me know what you think. THANKS!!!!

Capacitors

C1 - 77 UF
C2 - 128 UF
C3 - 1226 - 1763 UF (jumped around)
C4 - 1 - 4056 UF
- 2 - 5614 UF
- 3 - 4013 UF
- 4 - 5042 UF
C8 - 154 UF
C10 - 247 UF
C11 - 269 UF
C7 - 459 UF
C15 - 558 UF
C14 - 1676 UF

Transistors
B - .41
E - .40

Resistors
5W0.12 - (ohm)J - 0
5W2KJ - 192(ohm)
5W130 - (ohm)J - 137
 
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