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Robocop / Data East; Help please

Is there a connector plugged into cn18?? We are in system 11 land here and if cn18 is used then we are in system 7 land really with direct activation special sols .

The reason this matters is a stuck switch on a sling or pop bumper is going to be bad and cause a locked on coil. These early special sols are NOT cpu controlled because it was felt at the time cpu control would be too slow. There will be 2 switches per mech, one for score and one to activate the mech

So when you change those transistors check all the switches on the mechs. ( And of course the coil and diodes to)

Hi Jim - Thanks for getting in touch. Yes CN18 is in use on Robocop:

IMG_0430.PNGIMG_0431.JPG
 
Andy,

Each of the lines in CN18 connects to Ground (the White wire) when a bumper or slingshot 'activating' switch closes. When Williams originally designed the set-up, six drives were provided (enough for most games total of bumpers and slingshots). A switch closing changes a 'gate' input, probably in those small chips nearby, which sets off the relevant solenoid pre-driver, driver, and coil, connected via CN19. But a switch staying closed keeps the circuit On, with severe consequences.

For each bumper, make sure that the switch which closes when the footplate is deflected by a ball cannot remain closed afterwards. Is the bumper body breaking up? There was a topic recently where a cracking bumper body may have had a broken piece of plastic jam the plate down, and burn out the bumper circuit (Retroheed's Time Machine).
 
I’d also desolder the new coil you fitted to try to eliminate the issue, there may also be a short in the wiring , does anything around the bumper look stretched around a fitting
 
I’d also desolder the new coil you fitted to try to eliminate the issue, there may also be a short in the wiring , does anything around the bumper look stretched around a fitting
Hi Pete, that’s been removed since I realised the error of it being connected in reverse and the diode blown, along with it being the incorrect coil from my order. Cheers
 
Andy,

Each of the lines in CN18 connects to Ground (the White wire) when a bumper or slingshot 'activating' switch closes. When Williams originally designed the set-up, six drives were provided (enough for most games total of bumpers and slingshots). A switch closing changes a 'gate' input, probably in those small chips nearby, which sets off the relevant solenoid pre-driver, driver, and coil, connected via CN19. But a switch staying closed keeps the circuit On, with severe consequences.

For each bumper, make sure that the switch which closes when the footplate is deflected by a ball cannot remain closed afterwards. Is the bumper body breaking up? There was a topic recently where a cracking bumper body may have had a broken piece of plastic jam the plate down, and burn out the bumper circuit (Retroheed's Time Machine).
You may have nailed the original issue here mate. I had some
glass from a broken bulb fall
In the direction of the pop bumpers about a month ago. Thought I’d found all the pieces, yikes I best take the pop bumper put to make sure there’s no glass inside anywhere.

Hopefully if that was the issue, my hacked up mess of resolving hasn’t caused damage to anything beyond the transistors. I can dream
 
At least it's an (old-time) Stern type bumper, with the entire assembly offered up to a hole in the playfield, rather than the 'proper' arrangement of upper and lower components on either side. Easier on the production line, and in cases like this, though many dislike it.

Something I hesitated to suggest is to 'use the flexibility provided by the Special Switching arrangement' (or bodge if you prefer). Robocop doesn't have anything driven from the sixth Special drive circuit, even a flashbulb, so you could've moved both the switch wire and the coil drive wire in the slots of CN18 and 19 to the pins used for Special drive (SP) 6, rather than SP2 as originally wired. The Cpu and program couldn't tell how the bumper was being driven; the only giveaway would be in the Solenoid Test, where 'Unused SP6' would pulse the bumper instead of 'Center Bumper SP2'. Apart from personal preference, though, this depends on the unused circuit being in working order, and the playfield switching being okay - a dud switch (or coil) would simply damage another drive circuit.
 
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At least it's an (old-time) Stern type bumper, with the entire assembly offered up to a hole in the playfield, rather than the 'proper' arrangement of upper and lower components on either side. Easier on the production line, and in cases like this, though many dislike it.

Something I hesitated to suggest is to 'use the flexibility provided by the Special Switching arrangement' (or bodge if you prefer). Robocop doesn't have anything driven from the sixth Special drive circuit, even a flashbulb, so you could've moved both the switch wire and the coil drive wire in the slots of CN18 and 19 to the pins used for Special drive (SP) 6, rather than SP2 as originally wired. The Cpu and program couldn't tell how the bumper was being driven; the only giveaway would be in the Solenoid Test, where 'Unused SP6' would pulse the bumper instead of 'Center Bumper SP2'. Apart from personal preference, though, this depends on the unused circuit being in working order, and the playfield switching being okay - a dud switch (or coil) would simply damage another drive circuit.

Bumper checked over, no erroneous debris thankfully.
New correct coil soldered, diode correct way this time :oops: meter reading's taken across 3 bumper coils and 2 slingshots which make up the 5 on this circuit? All correct.

Visually I cannot see anything extraordinary: Please yell if I'm missing something

3 Bumpers
IMG_0493.JPG

Right Bumper:
IMG_0500.JPG

Left Bumper
IMG_0498.JPG

Centre Bumper (Original source of problem, new coil/diode fitted)
IMG_0501.JPG

In terms of checking the switches, is there a guide anywhere please? Showing where I meter to and from ?

@Jay Walker Once the 2N4401s arrive I can put the board back in, I imagine I'll need to go down the logic probe route first to check what I've fritzed upstream.
I'm certainly not averse to a hack (see my Tommy thread...) SP6 could definitely be in play should the new transistors not do the trick and the 7402 & PIA's test fine.
 
Regarding the direct/activating/'kick' switches, I'd connect one lead of the meter to the White ground wire, and then check continuity (buzzer or ohm reading) at each Orange/trace wire in turn. Maybe at the circuit board connector, to include the playfield wiring as well.

On the circuit board itself, looking at the schematic DE have simplified it from the Williams set-up. The 'SPICAL' switches connect to two chips, 7402 NOR (Not OR) gate devices.

The 7402 chip contains four identical 2-input NOR gate circuits, i.e. three pins each. Both inputs of a gate need to be digitally 'Low', near 0v, for the output to show a 'High' of around 5v.

SP2 uses one of the gate circuits in chip 12A, pins 4,5 & 6, with 4 as the output (the other three are used for SP1, 3 & 4, i.e. the other bumpers and the left slingshot). The switch input from the playfield appears at pin 5, so this should show a Low with the switch closed (a resistor in the package RA 24 pulls it up to a High otherwise). Pin 6 is used by the 'EN BLNK' (Enable/Blanking) line, common to all six SP drives. It drops to a Low when a game is started, and in diagnostics, turning back to a High and shutting off the drives in Game Over and Tilt. With both input pins at a Low, a High output on pin 6 (sorry, 4) switches pre-driver Q3 at its 'base' terminal, driver Q9 at its base and then the coil. Measure dc volts with the -ve lead of the meter on a good ground, such as the braid inside the back box, and touch the +ve lead/probe to the particular point under test, e.g. a chip pin. But take care not to bridge two pins with the probe. Maybe check through the switching side without the coils connected, at first.

Actually, going by the schematic the Cpu can't drive the special solenoids itself in any case, as with Williams short-lived System 9. So using SP6 instead wouldn't show that way.

The post from 'Snux', which i hadn't seen before, explains how the resistor, zener diode or/or capacitor associated with each special switch can fail, and cause a false switch input.

I've an explanation somewhere recent, about a slingshot circuit on a Gorgar. But that refers to the 2-gate Williams circuit.
 
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Awesome explanation, thanks @Jay Walker I'll do the buzz testing now.
Hopefully the transistors turn up tomorrow and I can get it back together and then probe looking for what you've described.
 
Hi @Jay Walker thanks again for your help, the 2N4401s have arrived and new ones soldered at Q3 & Q4.
I have not attempted to plug CN19 back in yet.

As I can't confidently decipher what is 12a & 12b I'll post the logic probe results visually, if you don't mind.

In Attract Mode (X indicates no reading at all)
12 Attract Mode.jpg

After pressing Start so in Game mode (Only one row changes)
12 Game Started.jpg
 
I hadn't realised about DE's board layout and I.d. methods, sorry.

It seems that their policy is/was to denote the board in sections from the upper left corner. Numbers are used from left to right, and letters from top to bottom. There are numbers and letters screened onto the board, but only one of each; the '12' is right there, but 'A' is much further away, next to the Cmos test point, C 157 and inductor L 2, below CN 17. So I see 12A as the upper of the two chips, Row 'A' as it were. It's more of a video game practice, I think.

Each chip has pins 7 and 14 for its own power and ground, though the schematic doesn't clearly show this. From your readings, I'd say 14, lower right, is power and 7, top left, is ground. The dot in the chip housing indicates pin 1.

The separate gates of the 7402 chip are;
  • input pins 2 & 3 switching output on pin 1 (SP 3 for chip 12A)
  • input pins 5 & 6 switching output on pin 4 (SP2)
  • input pins 8 & 9 switching output on pin 10 (SP 4)
  • input pins 11 & 12 switching output on pin 13 (SP 1)
In this case, the pin used for EN/Blnk pin is the higher number, so 12A's pins 3, 6, 9 & 12 should act together, High in attract mode, dropping Low with a game started and the flipper relay On.

The change shown in your pictures is the gate 8 & 9/output 10 of chip 12B, which isn't used as a solenoid drive; it's further up the chain, controlling the EN/Blnk line itself. That's behaving as it should, pin 8 drops Low to give two Low inputs, so pin 10 changes to a High. 12B does control two drives, SP 5 & 6, but from the gates on its upper edge, i.e. 2 & 3/(1) and 5 & 6/(4). The fourth gate of 12B switches the flipper relay, from pin 13, is that responding? It's an X in both conditions.

I'm worried that 12A doesn't show any change on its upper edge, the gates for SP's 1 3 and 2. Not only that, but all those pins are Low. With Low inputs, the outputs (pins 1 and 4) should be High. Maybe that short circuit has blown 12A, and possibly B.
 
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Thanks mate, great explanation for my donkey brains again cheers :thumbs: Really appreciated
I'll test pin 13 on 12B by activating the flippers when I get a mo, I'm suspecting that my error has frazzled both of them tbh.
 
@myPinballs my soldering isn’t the best on the CPU, however whatever has occurred in the past on back of the PSB has nothing to do with me 😖
 
Both boards now back fixed from @myPinballs :thumbs:cheers mate and fitted in the back box. All sorts of Gremlins running amok on first switch on but a factory reset resolved those (I hope)

Centre pop bumper the original troublemaker that began this thread didn’t appear to be working at first, although no errors were appearing in switch/coil testing and nothing was visibly locking on under the playfield. Checked the contacts and they were pretty far apart, so gave them a slight adjustment. Started a game and all pop bumpers working again… phew 😬

Fingers crossed that’s the end of this issue. Thanks all
 
Both boards now back fixed from @myPinballs :thumbs:cheers mate and fitted in the back box. All sorts of Gremlins running amok on first switch on but a factory reset resolved those (I hope)

Centre pop bumper the original troublemaker that began this thread didn’t appear to be working at first, although no errors were appearing in switch/coil testing and nothing was visibly locking on under the playfield. Checked the contacts and they were pretty far apart, so gave them a slight adjustment. Started a game and all pop bumpers working again… phew 😬

Fingers crossed that’s the end of this issue. Thanks all

Glad you are back up and running. 👍The cpu board was in a bit of a state with its direct solenoids, but now all sorted and back going as originally intended.

Also hope you enjoy the proper gi control now to
 
Didn't want to start a new thread just for this issue, however I don't seem to be able to complete a game without the ramp flap diverter/kickback eventually dropping too low and completely stopping a ball proceeding into the first saucer (multiball lock) or retreating backwards towards the VUK.
Over on Pinside someone noted that the part number is 535-5117-00, I'm not getting anything for this searching Google?

Obviously removing the flap would cause every ball to retreat to the VUK making multiball/arrest modes inaccessible.
Has anyone had any joy replacing or modifying the flap?
Thanks in advance.

1661080956924.png
 
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Just the 2 cracks then :confused: temp fix with gorilla extra tape and a couple of washers, not tested yet though.
Hopefully someone has made a replacement version somewhere.
flap.jpg
 
Glad you are back up and running. 👍The cpu board was in a bit of a state with its direct solenoids, but now all sorted and back going as originally intended.

Also hope you enjoy the proper gi control now to

Thought my eyes were playing tricks on me a few days ago, but today has confirmed it.
The GI has been gradually dimming, with the occasional flourish of correct brightness (when I hear the relay clicking rapidly on plunging)
It's now so dim, it's barely visible 😢
 
Thought my eyes were playing tricks on me a few days ago, but today has confirmed it.
The GI has been gradually dimming, with the occasional flourish of correct brightness (when I hear the relay clicking rapidly on plunging)
It's now so dim, it's barely visible 😢
Probably a new relay needed
 
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I should have recorded a video while the GI was still partially visible; when the ball launches the pop bumpers flicker which is how bright they should be post ball plunge mode but now they appear off with the rest of the GI locations. This was a gradual decrease in luminance rather than them suddenly not working.
@myPinballs Jim should I start with a new relay as you fixed the previous hack which was used to circumvent this? Or would I start somewhere else? I have given everything a wiggle to rule out dodgy connections.
 
Do you suspect that the relay contacts are burnt? I'm not aware of what's referred to as a previous hack, but the relay could be by-passed to prove this, before spending out on replacement.

The ac power for g/illumination arrives at the relay contacts on its 'Com'(mon) pins, 1 & 2. Most of the time the relay is off, so the Com points are (or should be) contacting the normally closed N/C points, 5 & 6. Going by the schematic, linking pin 1 to pin 5, and pin 2 to pin 6, eliminates the relay, though there'd then be no 'breaker' effect. This may of course be what existed as a hack, if so it does suggest the relay's at fault. As does the occasional sighting of full brightness as the relay operates repeatedly.
 
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Reflowing didn't fix unfortunately, will order a new relay once PM is back open next month.
 
F5 has blown twice today, not immediately on switch on like the initial issue this post started about. Everything worked for a few balls then ‘pop’ on both occasions.
Been working fine for a while too so I’ve not had to mess around under the playfield or fiddle with anything.
 
Had an ongoing issue with a fuse bLowing on my stars wars auto launch circuit, has turned out to be an in-line chocolate block connector which had been screwed too tight and fractured the cable Leading to intermittent current. Check your wiring out with a fresh eye!! I’d repinned power board, replaced coils, replaced fuse holders to no avail…..
 
Have checked the area which was at fault last year mpu CN19, TIP Q8-14, Q2-7 & R13-30 all seem to read comparatively with dmm.

Now removed the PSU, looks like you @myPinballs replaced C1,C2,C7 & C3 when you had both boards in August for repairs.
Could C11,C10 or C8 be responsible for F5 blowing I’m assuming these caps are still originals. Can I only test be removing one lug ?

Thanks

Edit: coil diodes all fine checked with dmm
 
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C9,C8 & Z1 are producing readings on the dmm, although I have no idea if the values are good or bad

3A4F45DA-3AF3-443F-B98F-594E3E37F4C2.jpeg
 
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