That has got to be the funniest System 80 hack I've ever seen.

Steve

Here's a simple BH mod I did a while back for those that never saw it.

Steve

LOL, I'm glad I don't know the answer to that Gerry.

Steve

I always liked the way the tube lit up on BBB so that was my version of it for BH. To light the tube, I used one of my LED post mod boards and installed super bright blue LED's on it. It's mounted to the cut out part of the playfield near to the upkicker tube edge so the light will travel through the tube to the end and light the tube up. I used the open gate light to power it. The only problem I ran into was the tube itself, it wouldn't carry the light through it very well because the plastic was old and beat up. My solution was to make a new upkicker tube, worked much better after that. You need pics too?

Steve

I remember your beautiful restoration Chris.

Steve

I have the stock part on the tube. I solved my cannon ball upkicker problem by converting to a A-20095 flipper coil and adding a EOS switch to it. That way, I can adjust the strength of the hit to the ball thus making it travel at what ever speed I want it to up to the main playfield. EOS opens late = cannonball, opens early = trickle onto the playfield. Also, this mod helps save the coil should a ground issue occur and locking on the coil. if that should happen, it's no worse than holding a flipper button on for a long time. It worked so well, I talked Cliffy into stocking the bracket and switch. Here's the PinWiki article on doing this mod.

http://www.pinwiki.com/wiki/index.php?title=Gottlieb_System_80#Black_Hole_Ball_Lift_Kicker_Mod

Gerry, it looks like the ball is hitting the edge of the playfield, there's an adjustment to correct this.

Steve

Here's a pic of my upkicker gate shield for pezpunk. Not sure why it came out dark with the flash on.

Steve

upkicker gate shield.jpg

HSTD is L11, this is controlled by Q11 on the driver board (MPS-A13).

Steve

My high score so far on this particular game.

Steve

BH high score 3-30-12.jpg

The easiest way I know of t get high scores quickly on BH (with the glass on ) in 5 ball play is to set the game up for multi-ball, get both G forces lit, go downstairs and knock down at least one the drop target and then trap the ball in the saucer. Then trap the second ball in the main playfield saucer. 3rd ball goes downstairs and try to knock down the remaining 2 targets so the gate opens and let one ball go so you only have to control one ball. Then you keep shooting the saucer in the upper left corner. When you hit it, the saucer is worth 12,000 points because of both G forces (6000 with one G force). Then you hold the left flipper up when the saucer releases the ball and it'll set up on the right flipper so you can do it again. Rinse and repeat a bunch of times, throw in 5 loops, maybe knock down the other four DT's and before you know it, you've got 350,000 in bonus X 5 and a EB. Do it twice in one game and you flip it a few. I had over 5 mill on my other BH, that's what got me thinking about changing to 7 digit displays.

Steve

Here ya go. I have the 6 to 7 ROM file, no more 6 second delay at start up, also has a dip switch free play option. So far, I've converted 4 games to 7 digit basically making a System 80 into 80A.

Steve

http://pinside.com/pinball/forum/topic/converting-any-system-80-6-digit-gottlieb-to-80a-7-digit

Too far away for me.

Steve

I don't like playing any game that's easy, to me, easy equals boring. I like 5 ball play on most early SS games, because the games won't hold back, they "bring it". So I have to as well.

Steve

DS 17, 3 ball play on, 5 ball play off. DS 20 is novelty mode, off is normal play.

Steve

Welcome to the club, another good addition.

Steve

That'll teach you to let your BH listen to whatever music it wants.

Steve

I'll never have to worry about rolling my game over.

Steve

I enjoy the torture so it's a 5 ball only game for me.

Steve

Most display issues in pair displays are usually at the CPU display connectors or on the CPU board (in your case with segment h, it would be bonus and status displays). If the problem only shows on one display, the problem is usually at that display, either connector related or on the display board itself. If I were a betting man and the problem is on one display only, I'd say the problem is in the punch pin type crimps Gottlieb used. ***With the power off***, if you jiggle the connector, does the segment come back after powered back on? If it does, it should be fine for a little while but the problem will come back. Only replacing the crimp will correct the problem (if it's in the connector).

Steve

Yep, that would create more push against the plunger returning to rest position. Good catch, I couldn't understand why more than one bracket would become magnetized, now I know why.

Steve

Probably a bad DS. One sure way is to solder a jumper to the back of the switch. I do that all the time to DS25 on all MGoW's to keep the switch in the on position, if off, the game never finishes the "game over" sounds and keeps playing background sounds after it's finished a game. The only way to clear the background sound with DS25 off is to turn off the game, then back on.

Steve

The drop targets coils are in A9J8/P8-7 & 8. Wire colors are red-brown-brown and red-orange-orange, check continuity through the connector. Also check connector A3J4-6 & 12 (same color wires) for continuity through the wires to the driver board.

By "ball through switch", I assume you mean the track switch (#53), for it to not work, either the tube kicker (#43) or roll under gate switch (#52) should also be dead for it to be a connector issue. If not, the problem is at the track switch itself. If the roll under gate switch is also dead, check A9J7/P7-2 for continuity through the connector. Wire color is yellow-green-green.

If the tube kicker switch is also dead, check connector A9J7/P7-8 for continuity through the connector. Wire color is blue-orange-orange.

I put the assigned numbers in this post so you can reference them when you test these 3 switches in switch test 18. If they show up as working when you touch the trigger wire with your finger, they are probably out of adjustment or dirty. Always clean or adjust switches with the power off, then re-test.

Steve

LOL, my favorite way to play a Black Hole but I really don't have the time tonight to join in the fun. My average scores are usually over a million on my game anyway, I know it too well.

Steve

Nope, glass on. Like I said before, rolling the game over was the main reason I had to convert it to 7 digit.

Steve

Knew you would. Knowledge is a wonderful motivator. Pretty soon, we'll have to convert your game to 7 digit so I can put a score on it for you to shoot for. The first time you roll the score, you'll be sad that you didn't convert it sooner.

Steve

Great score, somehow, I missed your post (until now). If you convert your game to 7 digit scoring, you won't have to keep looking for that score sheet. Here's the conversion thread:

http://pinside.com/pinball/forum/topic/converting-any-system-80-6-digit-gottlieb-to-80a-7-digit

Step it up to the next level and play it in 5 ball mode.

Steve

HA, all I see there is 221,610, you are no threat to my high score. A prediction for mof ... I see a 7 digit conversion in your future.

Steve

It's really not that hard to do the conversion (you don't really need the displays ... but it looks better), it's more time consuming than anything else re-working the display connectors. And, a ROM needs to be burned (PM for more info). The bummer for this right now is that I just talked with Ed at GPE and he said he's out of the U2/3 modules at the moment and he's been real busy so he hasn't made more. I told him that when he gets them back it stock, I'm ordering 3. If others contact him and get in line, he may get on it sooner.

Steve

Thanks Ed, forgot you frequent this site. Didn't mean to overload you ... well, maybe a little.

Steve

Yep, here ya go.

tn[3].jpg

As far as tube thickness goes, my replacement tube is the same thickness as original, had to special order it. If you need a new tube, I have a few extras made up that I sometimes sell at PAGG. PM me if you're interested in one.

Never thought of putting a red LED there, didn't even come into my mind.

Steve

(BHTFT) Black Hole tip for today: I was just telling mof last night that I went to replace the foam grommets (a couple of days ago) on the Black Hole and a Spirit I have in the shop/gameroom. I thought I had bought a bunch of them from The Pinball Resource a while back but I couldn't for the life of me find them anywhere. So ... I improvised and used some black "small mini post rubber" instead figuring I could replace them later if the rubber didn't work or hold up. I was surprised as to how well they worked at leveling out the plastic. I liked using them so much for leveling the plastic that I'm never going to use the foam grommets again. I'm sure that if someone else tries it, they'd say the same thing

Steve

The rubber crushed down real easy. Because it was more stiff than the foam, I was able to get the plastic/playfield adjustment real close to perfect and the screws are flush to the plastic.

Steve

Yay! Thanks Ed.

Steve

Kind of an odd issue. This problem is with D2 on all 3 displays and they're all driven by the same IC (Z17) on the CPU board. The odd thing is that the 3rd player display went out first, and then the other two started acting up. If this were connector (A1J3) or IC related, I would think that all 3 would have exhibited the same action at the same time. So instead, I gotta think that the first display to show the issue might be the one taking out the others. I'd try reseating the 3rd player connector or swap the display to a working display to see if it's bad, see if that helps (for starters). If that does help, you may have to re-crimp those punch pin connectors.

Steve

I may have them mof, call me later.

Steve

Here is the card that came in my NOS Black Hole card set. It tells the recommended cards Gottlieb wanted you to use.

Steve

Gottlieb BH recommended score cards.jpg

Glad you got it going and it wasn't a huge problem. Yeah, I see a afternoon of crimping in your future.

Steve

Okay, now what?

Steve

card back.jpg

The instruction card tells you that you can set your game from this.

score card front.jpg

To this by flipping it over.

score card back.jpg

Steve

You don't see it Gerry? The one's column on the right is active now and not a dead zero, what you actually are seeing is 999,990 but the score is slid to the right one digit to allow for the start of a 7 digit Black Hole (minus the four 7 digit displays, the next step).

Steve

LOL, sorry about that, I was just too excited to see another 7 digit Black Hole out there.

Steve

LOL, yeah, I think that happens a lot with a 7 digit conversion game. nudge nudge

Steve

I predicted this would happen 5 years ago, just took a little longer than I thought.

Steve

I've seen used 7 digit displays go for as low as $25.00 each but that was a while back when I first started doing the conversion. A long time ago, I bought a pallet of new 7 digit display tubes at $3.00 each so I went looking for display boards that had broken tubes on them. The cheapest I could find them was around $5-10.00 each. Now I'm out of the displays and will need to search for them too if I want to convert anymore games, I'm searching along with everyone else. I'd like to find a good deal on a bunch of those new tubes again since they seemed a lot brighter and more evenly lit when I used them.

Steve

I think I'd start with the lightest blue and work to the darkest just like they did originally with the screens.

Steve

Yeah, I know mine plays mean and nasty real well, it's dialed in too.

Steve

That's a mod I used to do but I came up with something I like even better Chris. You install 6VDC cool white LED's in the sockets, then add a 1K ohm 1/2 watt resistor between each of the 24VDC power leads to the sockets, shrink wrap the resistors and be done with that problem (bulb filaments vibrating and breaking prematurely).

Steve

Aack! Yep, I/2 watt. that's what I get for trying to type out tech stuff and get to work on time too. I thought it looked wrong when I proof read it but it didn't sink in, thanks for the catch Chris. Post corrected.

Steve

I don't get it either. Silly, useless sham-wow type fluff salesmanship that fails in very little time. Some people try to push junk to make a buck.

Steve

Glad you like the mod.

Steve

Good luck woz, I'm here if you need me by PM.

Steve

If any of your display tubes don't have a protector cap on them, you can put it in that player position, it should clear the screw then. Or you can take a little time and countersink the screw into the board (what I ended up doing so it would never bother me if I swapped them around). I used a 3/8" paddle bit for the countersink and slowly let it cut the depth less than 1/8".

Steve

That looks like a game that most of us wouldn't have touched or would part out, I know I would've walked away from it. Good for you Ib45 for taking on such a project, I assume that a Black Hole isn't something you come across every day where you live. The Pascal's System 80 four in one board is a work of art by itself. What do you plan to do to clean the rusty parts? I look forward to seeing your progress.

Steve

That CPU board (alkaline damage field) doesn't look as bad as I thought it would given the other parts I see in the pics, it can be repaired. I know I've repaired much worse than that.

Steve

That's a sign that your dip switch for 3 to 5 ball is dirty. Yep, 7 digit is needed. The cool part is that the conversion also gives you a free play option and gets rid of the 6 second wait for the game to boot to attract mode, it comes up right away instead. You can do the conversion in two stages too. Start with the U2/3 swap and do the displays as you pick them up. Your BH will be an 80A from then on. If you keep the 6 digit displays in the game, the one's digit will be activated as the 10's digit. Basically, it'll be the score you see X10.

Steve

I've heard that the rocker type dip switch is a little better than the slider type, has anyone also heard this? It may be true since all the one's I remember replacing through the years were the slider type.

Steve

rocker type dip.jpg
slider type dip.jpg

Glad you like the mod, I like not being the only one with a 7 digit BH anymore, I guess the mod is catching on a little. Along with the quick boot, you do know that the 6 to 7 digit program also has free play when dip switches 15 & 16 are turned on? Good job woz! The nice part is that that mod will work on any System 80 six digit game and Gottlieb didn't change the wire color assignments between six and seven digit games. Without that, the display wiring part of the job could have been a real mess and involve two more connectors. As a side note, I now save wire from parted out System 80 games, you never know when you'll need a specific wire color.

Steve

Those are indeed hard to find. I believe they were installed on showroom display games at places (like Betson) route operators would buy them. As with anything later, occasionally, they slip out to collectors. A lot of them were thrown out. I know the place I worked for did just that. If only I had the ability to look into the future, I would have been a dumpster diver back then. There was a reproduction of that promo sign done a few years back, I have one. It just isn't the same as a real one though.

Steve

It sounds like the game thinks there's a ball down on the lower playfield, as long as the game is waiting for the ball to return, no other coils will work. It could be that you have a stuck ball tube kicker switch #43. Before starting a game, using the test button on the inside of the coin door, try going through audits 16 through 20. Switch test 18 might be of interest, just be sure there are no balls installed and all drop targets are in the up position before the test. If any numbers show up in the credit window, you'll have to inspect/adjust that switch so it works correctly.

Oh ... and congratulations on getting a Black Hole.

Steve

You'll have to do a visual and move the switches using a ball or by hand to make sure each switch opens and closes. What are the numbers you saw in the switch test? It's possible that there's more going on than meets the eye, there could be a switch matrix issue. Try running the switch test again, this time with A1J6 unplugged and report back. If you get a "99" in the credit window then the problem is switch related (on the playfields). If you still get numbers in the credit window, then you have a switch matrix issue with your CPU board.

Steve

It looks to me like the return 0 (blue-black-black wire) and return 3 (blue-orange-orange) lines are being grounded out by something, 63 & 73 aren't used in black hole. You'll have to do a visual to see if there's a solder jumper or a switch that's too close to a light ground. Trace the wire colors from the CPU to the last switch of both lines.

Steve

I think the A1J4 to A3J1 connector may need some attention to your 5VDC and grounds. With the power off, try jiggling the connector and see if things improve when you play some games.

Steve

Way to go Eric! ....... next?

Steve

I have a 7 digit MGoW. It's borderline to do a conversion on it because it's a tough game to roll over anyway. However, it is nice to see that 7th digit when you do.

Steve

Have you made sure the A1J4 connection is good from the CPU to driver board? With the power off, try re-seating it to see if the issue improves. You may have to clean, re-tin the pads and replace the connector clip to make it solid.

Steve

If you've already rebuilt the connector, all the hard work is done. I still would re-tin all the pads since they can also be a source problem.

Steve

I think they're easy, you should buy it.

Steve

LOL, right now as some of my local friends will tell ya, I'm pretty hard to locate these days. I figure the way things are going, 2015 has to be better than 2014.

Steve

The one in my game was burned, cracked and filthy so I made my own but the correct tube size is hard to find. Only a few places nation wide carry it.

Steve

tn[2].jpg

tn[4].jpg

tn[4] (2).jpg

tn[10].jpg

This was some time ago, I can't remember, but I think the tubes were special order and came in 60" lengths. I ordered 3 tubes since I thought I may need to replace more tubes in my collecting future. I have a few "cut to size" tubes finished in the shop somewhere, but at this time, I'm not going to dig for them. I started too many other projects and need to get them under control first.

Steve

LOL, yep, if I can't get it, I make it.

Steve

Yikes, someone should jump on these for a BH 7 digit conversion.

Steve

I'm waiting for you to do the conversion too so I can stop over and put the new high score on your game.

Steve

BH high score 3-30-12.jpg

I think you have to contact Todd and ask about those displays, that's what I did last time I bought some from him.

Steve

Also keep in mind that though sometimes the power supply test points show as correct, the voltage can still be lost at the solder connection around the A2J3 connector pins. Loss of 5VAC line or return power through connectors A12J4/P4 or A10J3/P3 is not all that uncommon in BH either.

Steve

For me, nice cosmetics with the game being complete and not working is all I look for. I've bought them in the past from $300 up to $800. It's been a while since I've been in the market for one so I have no clue as to the prices now.

Steve

There are a lot of techs here that can and will help you when needed so it really isn't as scary as the stories you hear.

Steve

Switch test 18 is a good thing. Put your game into this test and bang on the playfield to see if any numbers come up in the display window. If any show up, adjust accordingly.

Steve

Check the fuse F17 under the lower playfield
Check the Q5 transistor under the lower playfield
Check connector A9J8/P8-2
Check connector A3J3-22
Check transistor Q15 on the driver board

Steve

I feel he's wrong on that one and choose to make my game more solid. The mods to the A4-A1 interconnect need to be done for a better 5VDC and ground connection between the CPU and driver boards. That's why the pads are there in the first place, cost cutting by the bean counters is what I've heard for the reason they're not used. The ground mods to the driver boards need to be done to insure a stable grounding system for the coil drive transistors.

Some BH's work well with the ball lift kicker the was it was from the factory. For me, far as the ball lift kicker coil goes, a must is the pull up resistor on that under playfield transistor (and all others). The schematic calls for a A-4893 (2.1 ohms) coil for that use, this is the strongest single coil Gottlieb makes. However, I use a A-20095 flipper coil with added EOS switch since the power coil inside is around 1.55 ohms (a little stronger). That way, I can adjust the strength of the kick with the EOS switch (contacts open early = weaker, open late = stronger). It's nice to see the ball roll up that tube clean without it beating up on anything now. It also helps to keep the coil from cooking should there be a drive transistor failure lock up and the coil stay activated. It can stay on indefinitely, just like holding the flipper button in for a long time.

Keep in mind too that from the factory, the ball lift kicker coil came over fused (6 1/4A Slo-Blo) and that's why it would always burn up when locked on, might as well not bother with a fuse then. The fuse wouldn't blow to protect the coil but a lesser fuse would sometimes blow during game play. This is the problem decision with BH, protect the coil or keep the game playing, Gottlieb chose to keep the game playing figuring that the coil would never lock on, with an eventual ground failure it will. With the ball lift kicker modification, I've been able to cut the fuse down to 2 1/2A Slo-Blo without problems in game function during game play.

Steve

I think that if it were easy, it would be boring and nobody would want it. Once in a while, I sometimes have a run like that, I stick with it and "rough it up" a bit until it decides to play nice.

Steve

I don't even use the black foam spacers anymore since they fail in time. I use the small black mini post rubber and it works fine in my game. They compress down to the thickness I need and hold firm to the adjustments I set the screws to.

Steve

It depends on how the capacitor is set up. If each capacitor services a different bridge rectifier, then you'll need two capacitors. If both capacitors service one bridge rectifier and have jumpers from one to the other, then usually one larger capacitor will handle the load.

Steve

I'm out of them right now but they look like these only in black. I'd have to look at my game now to see if I cut them in half across the axis, I may have.

Steve

white mini rubber.jpg

I think the schematic calls for a A-4893 coil which is 2.1 ohms, this is the strongest single purpose coil Gottlieb makes. I'm not sure what TNT used. On my game, I did the conversion and used a A-20095 super flipper coil, the power coil is 1.55 ohms and can make the ball fly up the tube if that's what you want. The nice part is adding the end of stroke switch to protect the coil from burning up if you have a ground failure at the driver board and making the kicker strength adjustable. Open early on the switch = less strength on the kick, open late on the switch = more strength on the kick. It's been documented in the link below but it's something that not everyone wants to do or should, it's just another choice;

http://www.pinwiki.com/wiki/index.php?title=Gottlieb_System_80#Black_Hole_Ball_Lift_Kicker_Mod

While at it, if missing, don't forget to add pull-up resistors on all remote mounted transistors under the playfields;

http://www.pinwiki.com/wiki/index.php?title=Gottlieb_System_80#Solenoid_problems

Steve
System 80. not just a job, it's an adventure

That's why I said, "if missing". Most of the BH's I've repaired in the past didn't have them. They aren't shown in the BH schematic either. Yep you remembered, 4.7K ohms, 1/4 watt.

Steve
System 80, not just a job, it's an adventure

I can't remember if it keeps saying it but that's where you score all the big bonus if you have both G-Forces lit while in multi-ball. Every time you go into the saucer if set up this way, you get 12K in added bonus. I usually let one ball go so I can gain control after I knock down a set of DT's to open the gate, then slam that "captive hole" saucer over and over again. Do it enough and you'll have over 100K in bonus pretty fast, add in 5X, dropping a second set of DTs to light either extra ball upstairs and turning over the game is fairly easy. Sometimes I can flip the game in one good ball on my BH (of course the rest of my game play usually sucks but I still get a good score).

Steve

I made my own.

Steve

Z4.JPG

Yeah, you can remove the 6VDC line from those lights. Then you tie them together with a separate line and run that line over to the L relay. Add another normally open switch to the L relay stack and jumper a 6VDC line over to the other solder lug. Now, those lights will only come on when the ball is down there or when you're on multi-ball.

Steve
System 80, not just a job, it's an adventure

Check the 24VDC bridge rectifier for your issue, it's probably failing.

Steve
System 80, not just a job, it's an adventure

They look like pull up resistors to me but not everyone installs them the same way.

Steve

I like that modification, it's a good idea. Whoever thought of it was a genius.

Steve
System 80, not just a job, it's an adventure

Black Hole doesn't have ball search that I'm aware of. Which game is this a picture of? It doesn't look like a BH at all.

Steve

Did you test the 1N270 diodes for those switches yet?

Steve
System 80, not just a job, it's an adventure

There's more to that test, open doesn't mean they work. True that the CPU sees all switches open, but you still need to close each switch during the switch test so you can see that the CPU knows the switch closed as well and that it assigned it the correct switch number. If it doesn't see the switch when closed, it could be a bad 1N270 switch diode, bad contact points or they can be out of adjustment. If the CPU sees the switch and assigned the wrong number, there is a switch matrix issue on the CPU board.

Other coils fire during the light test or if you manually activate the tilt relay during the test.

Steve
System 80, not just a job, it's an adventure

Connector: https://www.greatplainselectronics.com/products.asp?cat=77 Part Number: 09-01-6191
Crimps: https://www.greatplainselectronics.com/products.asp?cat=80 Part Number: 08-52-0072

Steve
System 80, not just a job, it's an adventure

Start by checking all your tilt switches to be sure they're operating correctly, also check the ball through switch to be sure it opens. Also, since the game is booting to attract mode, I'd suggest going into the switch test and see if you can find anything out of place. Look for switches closed and then check them to be sure the CPU and the switch are both the same. If you have all drop targets in their up position and all balls removed from the game, you should see a "99" in the credit window. Then you can test the switches to be sure the CPU "sees" them when they close. Check for switches that the CPU assigns a wrong number to them too, this can lock up your CPU and mean you have a IC short in your switch matrix.

Steve
System 80, not just a job, it's an adventure.

You need to go into the audits using the switch on the inside of the coin door and into test 18 (credit window), this is the switch matrix test. If you have it set up correctly, you should see a "99" in the credit window after you go into that test. If a bunch of numbers come up other than 99, write them down and report back here with the list.

Steve
System 80, not just a job, it's an adventure

Sys_80_test_button_top.jpg

That is probably the amount of extra games you have on your game. Each time you press the credit button, it should subtract one.

Steve
System 80, not just a job, it's an adventure

#51 is on the right #2 drop target downstairs
#60 is on the left #3 drop target downstairs
#70 is on the left #4 drop target downstairs

Pease be sure the drop targets downstairs are in their up position and check the switches to be sure they open when the targets are stood up. The switches are located on the back side of the drop target assembly. Then repeat the switch test and report back, hopefully you'll get a "99" in the credit window. Then there is a few switches we need to check.

Steve
System 80, not just a job, it's an adventure

Good! Okay, now go into switch test 18 and smack the playfield with your fist and see if any other numbers show up. If any numbers show up in the credit display, what are they? Also test the 3rd position ball return switch #25 by manually loading the game with 3 balls. A #25 should show up in the credit window. If so, proceed to test 20 and look for anything (other than a "99" in the credit window) in the player 1 or player 2 scoring displays. If you see anything, what is it?

Steve
System 80, not just a job, it's an adventure

Onion, from our phone conversation, here are the driver & CPU schematics for solenoid #9.

Steve
System 80, not just a job, it's an adventure

9_solenoid_driver_board.jpg
9_solenoid_CPU_board.jpg

Flow chart for solenoid #9;

1. F15 fuse/fuse block, replace if tested bad, if good VVV
2. A-16570 coil/diode, replace if tested bad, if good VVV
3. A3J4-8 connection, repair if tested bad, if good VVV
4. Q59 transistor on the driver board, replace if tested bad, if good VVV
5. A3J1-T connection, repair if tested bad, if good VVV
6. A1J4-T connection, repair if tested bad, if good VVV
7. IC Z30 (gate pins 10/11) on the CPU board, replace if tested bad

Usually by the time you get to here, the problem is fixed

Steve
System 80, not just a job, it's an adventure

There is a link to Great Plains Electronics at the top of this page
Chris Hibler on Pinside can do the board work for you if you aren't comfortable doing it yourself yet.