greyhound skill crane- wont go left!!

cadillacman

Well-known member
Joined
Nov 25, 2007
Messages
15,504
Reaction score
542
Location
Roscoe, Illinois
Hi guys. Im looking at a greyhound skill crane for a guy. Id like a second opinion to make sure ive diagnosed this correctly.

THis is an older greyhound, its all steel!!!

It has the 3 board setup in it ( logic, main relay board, claw board)

When i got to looking at it the claw did not grab and it would not go left.

I pulled and reseated all connections in the machine.

Now the claw closes properly but it still wont go left.

I checked +5, its at 5.25 I checked +12, its at like +14(seems high doesent it?)

I have checked the left micro on the joystick, it checks good with a ohm meter. I also powered it on and checked +5 at the switch, i have +5 untill the switch is acuated, so the switch is working and i know i have a good connection from the pcbs to the left switch.


The claw goes right just fine, and its a 2 wire motor correct? So the wiring between the pcbs and the left/right claw motor is assumed good.

I vote pcb issues... What do you think?
 
Last edited:
Is there a schematic available for it anywhere?
What drives that motor? The PCB? Without knowing much about the set up, if its the PCB, I would guess there is transistor driving the motor with a heat sink on it......
 
i dont know is schems are available or not.

ALL the motors seem to run off of the relay board. I suspect a krappy relay but who knows
 
Yeah that would be my guess, if they are driven from a relay, I'd bet dollars to donuts one of those relays are smoked......
Can you find the relay that drives the "right" direction, and swap it into the "left" position?
 
THey all look the same but who knows...

If the consensus is boards i found a working set for a reasonable price, this may be the way to go.
 
If it can go right, then it should be able to go left since it's the same motor controlling left/right

So either you have a loose connection on the bridge, or the joystick switch..

Lemme tell ya when a wire breaks in those metal sheaths its a pain in the ass to trace out.. even with ohm meter
 
If it can go right, then it should be able to go left since it's the same motor controlling left/right

Same motor, different relay. ;)

"Left" is the innermost relay. (RL7)
First thing I would do is see if you can hear or feel it click when activating "left".
That will at least tell ya which direction to troubleshoot in. (from relay board to the carriage or relay board back to CPU board)

The travel motor has three wires to it...one for left, one for right, and one for common.
So it could just be a break in the harness up to the carriage.
Very common problem.
 
If it's the standard 3 board set, you won't "feel" the relay's click. They are solid state relay's. You could have an older set with standard relay's, but those are pretty rare.

Couple of notes to troubleshoot:

Just because the joystick switch circuit toggles between 5v and low doesn't mean that the signal is getting passed to the CPU. U8 on the CPU board is the input buffer IC that handles the controls and it could be bad for that input. It's hard to test with anything other than a scope because the outputs are on the bus, along with most of the other IC's, so you will see logic activity on the output pin regardless of good IC/bad IC. If in doubt, replace it, 74LS373's are cheap and failures are not uncommon.

Same goes for U10 and U11, those drive the outputs. On Greyhound boards they drive the solid state relays directly. A bad IC can give you loss of a single, or multiple, direction. A fault here isn't very common, but possible.

Solid state relay's - You should be able to monitor the inputs and outputs of any suspect relay. For each relay, the two pins close together, toward the center of the relay board, are the controls, you should be seeing 5v going high and low as you move the controls. The pins along the edge of the board, are the outputs. NOTE - WARNING - the relay outputs are LINE VOLTAGE, use caution !! You should see the output going 110vac to 0vac as you operate the controls. If your inputs are toggling and the output is not, you have a bad SS relay.


Shameless plug ---> I have Greyhound board sets on eBay right now, both for exchange and outright sale.


D
 
If it's the standard 3 board set, you won't "feel" the relay's click. They are solid state relay's. You could have an older set with standard relay's, but those are pretty rare.

True... I was just going off it being an "older" machine as far as feeling the relays.
Glad you noted the difference.

Shameless plug ---> I have Greyhound board sets on eBay right now, both for exchange and outright sale.

Nice, really don't see boards for these come up often...at all. Especially full sets.

What all ROM revisions do you have? (date codes and whatnot)
 
If it's the standard 3 board set, you won't "feel" the relay's click. They are solid state relay's. You could have an older set with standard relay's, but those are pretty rare.

Couple of notes to troubleshoot:

Just because the joystick switch circuit toggles between 5v and low doesn't mean that the signal is getting passed to the CPU. U8 on the CPU board is the input buffer IC that handles the controls and it could be bad for that input. It's hard to test with anything other than a scope because the outputs are on the bus, along with most of the other IC's, so you will see logic activity on the output pin regardless of good IC/bad IC. If in doubt, replace it, 74LS373's are cheap and failures are not uncommon.

Same goes for U10 and U11, those drive the outputs. On Greyhound boards they drive the solid state relays directly. A bad IC can give you loss of a single, or multiple, direction. A fault here isn't very common, but possible.

Solid state relay's - You should be able to monitor the inputs and outputs of any suspect relay. For each relay, the two pins close together, toward the center of the relay board, are the controls, you should be seeing 5v going high and low as you move the controls. The pins along the edge of the board, are the outputs. NOTE - WARNING - the relay outputs are LINE VOLTAGE, use caution !! You should see the output going 110vac to 0vac as you operate the controls. If your inputs are toggling and the output is not, you have a bad SS relay.


Shameless plug ---> I have Greyhound board sets on eBay right now, both for exchange and outright sale.


D

yeah im counting on those lol

yeah these relays dont click. I did not know the bridge motors were ac motors. I guess i have more testing to do.

i think what im going to do is bring my boards from my crane over there. If mine fix his issue then there we go. then i will buy your boards to replace mine. If my boards do not fix his issue, then i will know to keep digging.
 
Last edited:
I'd measure the output voltage to the motor and Ohm the harness.

"Bottom Side" means the solder side in this thingy I just did up......
 

Attachments

  • Grayhond Control Board.jpg
    Grayhond Control Board.jpg
    91.3 KB · Views: 13
What all ROM revisions do you have? (date codes and whatnot)


A couple of different ones, the image I use to burn new eproms for the boards is the 1992 version. 1987 seems to be very common. I haven't seen any real operational difference between any of the revisions. There may be some additional coinage options in the newer versions, not sure.

Since all revisions I have come across seem to work pretty much the same, from an operational perspective, I tend not to bother replacing, or erasing and rewriting, working eproms, therefore I haven't taken the time to image the various revisions, or look into any potential differences.

Can't imagine the older versions would contain much in the way of bugs, how hard can it be to code up, down, left, right and drop claw !!! :)
 
I haven't seen any real operational difference between any of the revisions. There may be some additional coinage options in the newer versions, not sure.

That's what i was curious about....what minor differences tat there may be. I couldn't think of much that would be either, but I haven't had any other versions to play with.

Can't imagine the older versions would contain much in the way of bugs, how hard can it be to code up, down, left, right and drop claw !!! :)

:) Hehe, yeah , I know. Maybe some have music and some don't or something like that. (?)

If you get a couple images I might be interested in playing with them.
Mine is 11 21 1993 if you want it to check out.
 

Attachments

  • Grayhound Candy Crane.zip
    3.2 KB · Views: 4
Last edited:
Lemme tell ya when a wire breaks in those metal sheaths its a pain in the ass to trace out.. even with ohm meter

No shit! We have some newer cranes where the carriage wiring harness wasn't made right (but naturally the manufacturer denies there's a problem) and wires break in them ALL THE TIME. It always takes me an hour or more to figure out where the break is.
 
Back
Top Bottom