Atari Middle Earth issues

thebman80

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I'm having some issues with my Atari Middle Earth. I have the game working down to the flippers and the displays. All 4 flippers just wont work I have checked the fuse and the main drive transistor and they're both good. I even checked the drive transistor twice. I cant find any information about what the correct readings are for a working Atari flipper coil. I'm doubting that all 4 are bad but who knows with this pin? Is there any way this could be caused by a logic issue or is that just not possible?
 
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Set the meter to 200 ohm and this is what I got for each flipper coil.

Left bottom: left and middle 5.5, right and middle 152.2, two outside prongs 160.6

Right bottom: left and middle 5.4, right and middle (no reading), two outside prongs (no reading)

Top left: left and middle 6.0, right and middle 160.9, two outside prongs 166.9

Top right: left and middle 5.2, right and middle 154.4, two outside prongs 159.3
 
Yes the side flipper buttons. Even if 1 coil was open the other 3 should fire.
 
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Yeah I tested the side buttons with my meter. They make contact when the buttons are pressed.

I'd say you have a problem with the bottom right coil.

Rodger Kilgore

Yeah I was thinking that one was probably bad but all of what I'm guessing is the thin side of the coil measured quite high. The 160 range seems quite high to me most coils I have seen usually don't go above 50 to 60 ohms. I just need conformation with the measurements not sure how many people have Atari pins here.

Here is a picture of the only labeled flipper coil, this was the top left coil in my game.

bf9ef3c633160caafea93875ff9171b8128e654b.jpg
 
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Ah finally I found the coil values for the flippers. Looks like all but one is good.

Atari # A020470-01 (25/790) is the flipper coil. Has two diodes installed. The high current pull-in winding is 4.5 ohms dc resistance. The total resistance of the pull-in and hold windings is approximately 150 ohms. The coil has 1/4" quick connect terminals, so no soldering is needed. Uses Atari coil sleeve # 006791-01.

This is Gen 2 Atari games like Superman looks like I'm going to have to take a look at the PCB as well. There has to be something similar going on here.


6.2.1 Power Driver Issues

Pertains to Atari Superman and Hercules pinball (Atari Gen2 Circuit Boards)
If all playfield coils except for the flippers do not work, the likely suspect would be the chip enable circuit that is based around the CDN4013 chip located at B4/5, and also utilizes the MPS-A06 transistors at Q65, Q66, Q81, Q106 and the SJU783 transitor at Q103.
Other than the chip-enable circuitry, the solenoid driver section on the Gen2 Atari driver board is a very simple circuit layout. A single MC14514B line decoder controls each of the individual solenoid circuits. Each solenoid circuit consists of only an MPS-A06 pre-driver transistor, which drives the SJE783 driver transistor.
There is some confusion regarding driver transistors, as the schematic lists the driver transistor to be an SJE783, while the board layout lists a 2N6041, but most boards used an RCA8203B. The SJE783 is essentially impossible to find any information about, and the RCA8203B has been unavailable for quite some time. While the 2N6041 is available, a cheaper and more robust alternative would be the TIP107. Note that this applies only to Superman and Hercules boards, earlier machines used different components.
The MPS-A06 is still a commonly available part through most large electronics houses.
 
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Going on that information this is what I found in the manual on Pages 39 and 43. Looks like I will have to take a look at the logic. I believe I got that right says latch bit 6 1088 and the diagram on page 39 shows 1088 latch 6. So will have to take a look at the chips at locations D16 (page 43), C14 (page 39).

Atari%20Middle%20earth%20Flipper%20%20IC%20path.jpg
 
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I have to look at my space riders. I could swear there is a relay for the flippers. It would be very odd to directly enable the flippers from the logic alone.
 
Well there is a Relay on the main power brick I can see it latch on when the game is turned on and the other playfield coils reset. I was getting continuity through the wires all the way from the fuse to that relay. Tested continuity through the fuse into the PCB through the transistor up to where is goes into some resistors then into an IC which all seemed good as far as the electrical path in concerned.
 
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I don't know why or how but the flippers started working on their own. 2 are dead so I have replacements on the way.

I do have another issue anyone have a middle earth or similar Atari Pin? I need a picture of the Aux power PCB especially the J14 tiny connector with 3 wires that powers the displays. I think someone might have swapped the top and bottom wires and need to confirm this with someones game. from what I gather from the schematics it looks wrong but I have already dealt with wrongly labeled stuff before in the manual with this game.

I finally got 90v into the Aux PCB from the power supply Just haven't been able to get it back out to the displays yet. I have replaced a lot of the stuff in the 90v section and still nothing off the AUX PCB.
 
When repairing most display power supplies your better off replacing everything in that circuit, replacing part of it usually causes other parts to fail.

Rodger Kilgore
 
Well so far so good I got the flipper coils today still need one of the flipper arm assemblies since mine is hacked. Now on to debugging the score displays.

 
This gives me hope. I bought a project space riders we are planning on doing a full restore on, including the playfield. I am slowly storing all these atari posts to the computer, so I can go back and look once we get down to the actual work of putting it back together and testing.

They are such unique and beautiful widebodies......I just couldn't pass up the chance to have one.

Good luck with yours as you move forward, and thanks for sharing all this!!!
 
I have a Space Rider, I love that pin... well it's my ONLY pin so... But I have display "laziness" When I power on the game it usually takes a bit to get the displays to do much but after a bit they work ok.
 
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