Granny and the Gators Repair Log and Info

Azure Oz2

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Donor 6 years: 2020-2025
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I am documenting the repairs on the Granny and the Gators I am repairing (not mine). This game needed quite a bit of work and in my searching I found a lack of general info and some incorrect information. I have almost finished and don't really have any before pics for reference.

This is a rare game so I want to document as much as I can while it is here for repair. Hopefully this will help others in the future.

I will try and break down the work in separate posts for each section of the game as well as pics. If you want to see larger pics, just click on them to enlarge the thumbnails.

Here is the now working machine. Side view shows some of my parts drawers in the background :)

Front Cabinet.jpg Side Cabinet.jpg

In the background is also a side view of a Baby Pacman (water damaged cabinet base) that is also in for repair. This is initially to be used as a donor for any needed parts on the Granny and the Gators. It will be repaired later.
 
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First work was to remove the Monitor, PCB's and Power Module to check everything out. Doing this reveled battery leakage corrosion to some harness connector plugs and two pcb's. There was also corrosion on the control panel plug, possible from a spillage. Several parts were missing and broken.

The monitor was rebuild in a separate thread. I have more info that I will post there later.

Here is the monitor (M) in the cabinet. The parts list and setup is for a Wells Gardner 13" but there was a schematic of the Electrohome G07-FBO, model G07-902 in the online pdf I was able to find.
Monitor.jpg

The PCB's used are:
AS-2518-132 Power Module (A2)
AS-2518-133 Pinball MPU ( (A4) this machine has a AS-2518-35 converted to a -133
AS-2518-107 Lamp/Solenoid Combo (also MPU 5 Volt regulator) (A3)
AS-2518-121 Vidiot Deluxe (V)
A080-91603 Cheap Squeak (A8)

A2 Power Module pcb is in the bottom. It is part of the Power Transformer Module AS-3071-12
Rear Power Supply.jpg

V Vidiot Deluxe pcb is on the left side with the A8 Cheap Squeak below it
Rear left pcbs.jpg

A8 MPU pcb is at the back above the A3 Lamp/Solenoid Combo pcb.
Rear centre pcbs.jpg
 
Here are some harness, coin door, control panel wiring pics and one of the playfield.

Coin Door wiring
Coin Door wiring.jpg

Control panel wiring
Control Panel wiring.jpg

Rear inside left harness
Rear left pcbs.jpg

Rear inside right harness
Rear right wiring.jpg

Playfield in attract mode. Most GI lamp are dead, which is why it is so dark. Three LED's fitted for testing: top middle rollover white LED, 2nd rollover Green LED and top GI green LED.
Playfield feature lamps.jpg
 
This machine is in Australia, which is amusing since we have Crocodiles not Alligators.

Changing Mains Input Voltage and Testing the Power Transformer Module

I will refer to the US line voltage as the generic (old school) 110V - like the machine.

It was setup for US 110V. Luckily the Power Transformer Module supports 240V. Here are the steps to convert it to 240V.
1. 110V Power lead removed and replaced with 240V plug and lead.
2. Power connector wiring changed to configure Transformer for 240V input.

Connector plug wiring changed from:
3 Jumpers linking pins 2-8, 3-6 and 7-10 for 115V
These were removed and changed to:
2 Jumpers linking pins 4-8, 7-11.

Voltage Selection wiring. 110V on left (pic from BP), 240V on right.
Voltage selection 110V (BP).jpgVoltage Selection 240V.jpg

3. There was no Varistor on the mains input so nothing had to be done there. If you are converting a machines input voltage you will need to check and change or remove the 110V Varistor if changing the wiring to one suitable for 240V. You will know about it if you don't and there is one there.

4. Sourced missing fuse cover, clips and screws from donor unit. Gave the PCB and fuse cover a wash with simple green, rinse and dry with compressed air.

Power Module pcb before cleaning (pcb from BP).
Power pcb before (BP).jpg

5. The A2 Power Transformer Module was powered up on the bench. All voltage outputs were correct. During this test while bypassing the on/off and interlock switches I found that the schematic does not correctly show the mains input wiring. I will post a correct power wiring schematic later, when I draw up my messy notes.

Finished Power Block back in machine.
Power Block finshed.jpg
 
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Control Panel Repair

The control panel had some issues. when the game was running it felt like the paddles were not responding properly or possibly it was my woeful game playing. In switch test mode it also felt like they were not responding quickly.

A quick note about test mode: In switch test the playfield switches once activated are slow to appear on the screen. The control panel switches seem quick to appear once activated.

Looking at the microswitches the button activation felt very weak, no clicking sound. I desoldered the terminals and removed all three.

Old microswitches.
Control Panel microswitches.jpg

All three were replaced, new diodes fitted and spade terminals added to the wiring to make future servicing easier. Make sure to fit the diodes and wire them in the correct way. Not all diodes are shown on the wiring diagram pdf I found. They were on the switches so I replaced them.

One of the new microswitches with spade terminals added.
New microswitches with spades.jpg

After assembly the switches were now responding much more consistently in play and test mode. The buttons still felt a little slow in the return so I removed the button housing and gave them a minor, careful, clean with Simple Green. I was careful not to let any liquid get into the switch caps in fear of damaging the labels in there. The button sides and body were quite dirty. After cleaning the buttons felt much more responsive as well. I did not want to risk breaking the button caps but it would have been nice to open them up and clean under the button caps.

While working on the control panel I did remove it to do the rewiring on the workbench. It was at this time I noticed the connector halves were stuck together and it looked like some pins were burnt. I thought that was strange as it only carried switch signals and powered 3 wedge globes. It turns out there must have been a spillage that leaked onto the connector and caused corrosion on the pins.

Control Panel plug with corrosion and the bad pins replaced. Hard to see but worst corrosion is at the contact mounting point not the mating area.
Control Panel Connector.jpgCorroded control connector contacts.jpg

There is a Bally Midway Service Bulletin dated 14th October 1983. It mentions a 1N4148 may be wired into the Powed button lamp on the control panel. This needs to be replaced with a 1N4004.

Diode replaced with 1N4007 (I have plenty of these in stock. It is the same 1A version with a higher voltage rating than 1N4004).
Power lamp diode mod.jpg

Completed Control Panel. The Power Button Lamp is a feature lamp, managed to get it while on for the pic.
Control panel.jpg

The owner is sourcing a new overlay as this panel has been painted solid green.
 
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Coin Door Repair.

The Coin Door has the test switch and volume control mounted on it. The test switch was very intermittent, quite noticeable as you stepped though the test modes. It was replaced. The leads on the volume pot were also all bent, they were able to be straightened back up.

The ground strap to the front door was also broken on one end. It was still long enough to reattach. A new hole was drilled on one end and the strap screwed back in on both ends.

Old Test switch and new Test switch fitted with heat shrink over leads.
Test button.jpgNew test button wired in.jpg
 
Vidiot Deluxe Repair. This post is a bit long. I hope it contains some useful info for others in the future.

On first inspection there were two blown up Tantalums. These were removed and replaced. They are part of the input filtering and do not need to be tantalums so electrolytics were used. Pics of original Tantalums, one not so happy, the other is shorted. New electrolytics fitted.
Vidiot Deluxe faulty tantalums.jpgVidiot Deluxe caps replaced.jpg

There was no corrosion. This pcb is not close to where MPU battery leakage occurs and no wires had corroded on the connectors for the Vidiot Deluxe. A clean of the pcb connector pins was done.

There are several pots for video output and sync levels. The video game uses two TMS9928 VDP controller IC's and the outputs from these are Y, R-Y and B-Y. The VDP outputs are converted and combined in the output stage to RGB, where the pots are. The switching between the VDP outputs is also done by one of these pots. These were left as is for now.

The board was powered up one the bench. There are supposedly 14 flashes when in a working machines. The test LED is shared with the Cheap Squeak, which normally does the first 2 flashes, the Vidiot Deluxe waits a few seconds for those before starting it's self test. With 12 LED flashes on the workbench all was good to test the video output.
Vidioit Deluxe on workbench.jpg

I remembered while servicing the monitor the video connector was wired for positive sync. I still had lots to do on this machine, I went and repaired the lamp/solenoid combo driver board next. I did this because the wiring seemed to go through it. Jumping ahead after that was done, checking voltages to the Vidiot Deluxe were ok, I connected and powered the Vidiot Deluxe up in the cabinet. I got no video output and I know the monitor works.

According to the manual if the boards are not working there will be no video output. This is correct, you will get a blank raster after the Vidiot Deluxe initializes until it gets a command to do something from the MPU. You can get video output with just the Vidiot Deluxe running. After the Vidiot Deluxe passes the self test LED flashes, press the test button on the Vidiot Deluxe pcb. the first press gives you the communications screen the second press gives the video test pattern.

I still had no picture, so I carefully adjusted some of the pots and started getting an image. The pots are very finicky and some were glitchy. I removed the board and on further inspection the Luma pot had limited physical movement. I noticed the black gunk, I suspect this was added after the pots were originally set to lock them in place. All had been moved. Since some were glitchy I replaced them. Some had been worked on before.

PCB with original pots and pots replaced.
Vidiot Deluxe old pots.jpgVidiot Deluxe new pots.jpg

Now I was able to get the video test pattern back and start adjusting them until I managed to get good foreground text colors (slave VDP) and nice background color bars (master VDP).

After passing self tests there is no video. 1st press of Video Deluxe self test gives communication screen (icons on screen are blown out in pic but look fine in person), 2nd press gives test pattern.
Vidiot Deluxe comms test.jpgVidiot Deluxe video test pattern.jpg

Here is where the pcb mounts in the cabinet and the pcb back in place. Finally the game powered up in attract mode and looking good (MPU also fixed).
Vidiot Deluxe pcb location.jpgVidiot Deluxe pcb fitted.jpgAttract mode.jpg
 
Lamp/Solenoid Combo Repair. This post is much shorter.

There was severe corrosion on this board and the Baby Pacman donor. I chose the donor board as the lesser of two evils. The pcb in the machine has had some not so good previous repair work done on it. They are mounted in different places relative to the MPU, the battery leakage point, in each machine creating the corrosion in different places.

Some connectors had bad corrosion so I swapped them with the other pcb to get one repaired.
Corroded Combo Connectors.jpg

The solenoid Transistors had some corrosion and on closer inspection it was on all of the legs. To save having any problems I removed and replaced them all with new ones.
Corroded Combo Solenoid Drivers.jpg

The last repair was when the game was running and I was able to do a lamp test. It took me two passes as it also involved fixing some playfield issues that I will cover later but there ended up being 4 faulty lamp driver Thyristors.
Faulty Combo Lamp Drivers.jpg

Here is the board all repaired and back in the cabinet. The voltage regulator was checked and ok.
Repaired Combo.jpg

An interesting side note. These and some later Bally pinballs use 1 Thyristor to drive 2 lamps. The 2 lamps are connected to opposite phases of the supply and the Thyristor is switched on during the appropriate phase for each lamp. Earlier machines only used 1 per lamp, requiring twice as many lamp drivers as this new method which lowered costs.
 
MPU Repair. The MPU in the machine and in the donor were both AS-2518-35, not the original AS-2518-133 pcbs.

There is only 1 difference between the -133 and the -35. The -35 needs resistor R113 change to a 1N4148 diode. Here is the resistor changed on another pcb (not done by me), it is in the middle of the pic.
MPU -35 Mod.jpg

There was corrosion on both the candidate pcbs. The one in the machine was missing the 6800 CPU and both 6821's. While I was deciding which one was better to repair I checked the ROM numbers from the one in the machine..... they are ROMs for a Six Million Dollar Man pinball! how was that ever going to work. Given it was strapped for the wrong ROM type and size and there were chips missing and corrosion damage to fix I went with the donor MPU.

It was strapped for the correct size EPROMs. I tested the 6800 and 6821's in a Back-Bit Chip Tester Pro and they passed. This MPU had already been repaired (by someone else). I scraped away at the corrosion areas to make sure they were ok. I may add some resist mask if I get the urge later.

MPU Jumpers.
Jumpers for AS-2518-35 MPU to use 2732 EPROMs in position U2 and U6. Ensure you remove any other links.
E4 - E13A (jumper wire)
E7 - E8 (link)
E10 - E11 (link)
E12 - Gnd (jumper wire)
E16A - E29 (link
E31 - E32 (link)
E33 - E35 (link)

I programmed a set of Granny and the Gators MPU EPROMs, U2 and U6 into 2732's and put some labels on them.
MPY new EPROMs.jpg

Next was the Battery Backup RAM, a 5101 and it's missing battery. I decided to build and test one of my FRAM replacements. If it worked it would not require any battery, a big plus in fixing these damaged MPU's. I assembled it and tested in the Back-Bit Chip Tester and in the RCT Pro, it passed in both. It was placed on the MPU. It is a nice compact pcb size (only a little wider than a 5101) that does the full 2 pin select decoding.
MPU with FRAM.jpg

It was time to work on any repairs needed so I powered it up on the workbench. I got the required LED flashes. It was time to fit it into the machine.

Before fitting it I checked the harness MPU plugs. The right side connectors had corrosion. I do not have spares this size in stock. So I cleaned each pin contact and repaired a couple of bad wire connections. The contact Tin plating had not been damaged, only surface corrosion buildup. If the connections are not reliable I will order replacement and wire them in.
MPU back in.jpg

Powered up the machine. After the required self test flashes from all pcbs it greeted me with the game in attract mode.
 
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Cheap and Squeak. No repair, turned out it just needed an adjustment.

I checked the pcb while I had them all out and there was no visible damage or corrosion. The harness connectors were also ok.

When the game powered up into attract mode it was making no sound. Playing a game also made no sound. Pressing the test button on the pcb made no sound. I checked that during powerup the LED flashed 2 times, this made up the full 14 flashes on the Vidiot Deluxe.

Adjusting the volume control on the coin door made no change. The speaker metered ok. Checking the volume control on the pcb revealed it was turned all the way down. It was set it to a suitable level to allow the volume at full on the front door to go as loud as wanted. Then set the volume on the front door.

Here is it in the machine.
Cheap-Squeak fitted.jpg

Some test notes.
With the Vidiot Deluxe connected the LED on both pcb's flash in time. With J2 on the Vidiot Deluxe disconnected the Cheap-Squeak LED will stay on after the second flash. These flashes do not appear on the Vidiot Deluxe pcb with J2 disconnected.
The game will power on if the Cheap-Squeak is not working. So it is not needed to pass self tests and play a game, it will just play with no sound.
 
That is most of the main repair notes.

I will check my repair notes to see if I missed anything or additional useful information to post.

Playfield Repairs.

In self test and game play all solenoids worked. The new Transistors fitted to the Combo board may have helped.

Playfield parts bottom.
Playfield bottom.jpg

Most playfield switch contacts were dirty and not making consistent contact. They were cleaned with my last piece of micro-scrub that I have from back in the day to clean gold contacts and also wiped clean with fau-chami swabs moistened with some iso.

There were a couple of switch assemblies that looked like they had cold solder joints. They were resoldered to make sure there was good contact.

There were many dead feature and GI lamps. All working GI lamps were removed and used for the feature lamps. After replacing any not working lamps fault finding started under the playfield. There were a few frayed and broken wires on the wedge lamps in front of the drop targets. They are from movement reaching in to a tight space to change the lamps over the years. They were stripped, tinned and resoldered to the lamp connections.

Playfield area of broken lamp wires.
Playfield broken wires.jpg

There were also a few wedge lamp brackets not properly soldered to the bare braid. I think they like that from the factory relying on metal on metal contact. The metal tarnish has built up over the years making the contact now open or at best intermittent. Resoldering with some fresh flush fixed them.

Example of poor Playfield lamp bracket soldering.
Playfield lamp soldering.jpg

As mentioned in a post above there were some faulty lamp drivers that were replaced.

The right hand ejector solenoid bracket was catching on the control panel latch every time the playfield was lowered. The latch tab had to be lifted to properly lower the playfield. While resoldering a bad wedge bracket solder connection I noticed the solenoid mounting bracket was bent. This forced it closer to the catch than it needed to be. Straightening it up the playfield now lowers without catching on the latch.

Playfield solenoid bracket (straightened up).
Playfield bent bracket.jpg

There is some incorrect online information, there are no slingshots in this game. The two sections above the flippers are solid plastic with no switch contacts and a post rubber ring located at the top and bottom.

For reference here are some quantities for playfield parts.
Rubbers:
21 x Rubber post caps (instead of acorn nuts that go on the top of the posts to hold the plastic down)
2 x Flipper rubbers (Part A in playfield drawing, # 0017-00041-0653)
1 x 1" Diameter rubber (Part B in playfield drawing # 0017-00041-0643)
6 x 5/16" rubbers (Part C in playfield drawing # 0017-00041-0637)
3 x Post rubbers (Part D in playfield drawing # 0017-00041-0641)
5 x Mini Post rubbers (not in rubbers, playfield parts 15 & 16 mini-posts with 3 x # A360-00218-0000, 2 x # A967-00063-0000 )

Playfield layout, hopefully you can see where the rubbers are (they are not all shown in the manual).
Playfield top.jpg

Lamps are all wedge globes types:
20 x Playfield general illumination (I would recommend using white is going to colored LEDs)
2 x Coin entry lamps
3 x Buttons (I would use 3 x green and 1 x red if going to colored LEDs)
38 x Feature Lamps (If going to LED they are in the following colors)
5 x White (saucer top lamp, letters for E X I T)
17 x Green (10 rollovers, saucer middle lamp, letters for P O W E R, side gate)
6 x Orange (saucer bottom lamp, letters for G O L D, above outhole)
10 x Red (left and right lanes, letters for A M M O, number 5 10 20 50above flippers)​

Playfield Feature lamps.
Playfield feature lamps.jpg

There is a minor typo in the one sheet summary for Granny and the Gators. Canoe rollover wiring for lamps #5, #6 and #8 are mixed up. The original manual is correct. This is due to low quality pdf. It would be great if someone has an original that could post a better quality pdf.
 
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Mains Wiring.
The mains input wiring is not drawn correctly in the manual. Here is a drawing of the correct wiring.
Granny-and-the-Gators Mains Wiring.png

MPU Jumpers.
Jumpers for AS-2518-35 MPU to use 2732 EPROMs in position U2 and U6. Ensure you remove any other links.
E4 - E13A (jumper wire)
E7 - E8 (link)
E10 - E11 (link)
E12 - Gnd (jumper wire)
E16A - E29 (link
E31 - E32 (link)
E33 - E35 (link)

PCB Spacers.
Four pcbs use Nylon lock-in standoffs which may be missing or have broken locking tabs. There are 4 on Lamp Solenoid Combo, 4 on MPU, 4 on Vidiot Deluxe and 2 on Cheap-Squeak for a total of 14. The size for these appears to match Keystone part # 8815. I used donor parts to replace any missing/broken ones.
The Power Regulator pcb uses different through hole spacers which i think are like Keystone part # 9035. These are less likely to break or go missing.

After reviewing my notes that is everything I can think of. The machine has been starting up without any issues and running reliably for several days now.

I hope this information may be of use to others in their Granny and the Gators repair endeavors. Hopefully in the next few weeks I will be able to make a start on Baby Pacman.
 

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