Robotron boards

[R177]

Hello, please go easy, I'm a new user and not too technically minded!

Anyway, I've got an upright Robotron thats been lurking in my house, unused for a few years. So, when I went to turn it on, everything seems to work OK except none of the controls works.

Running through the test sequence, everything is fine until the 'switch test'. The coin mech switches work but no joysticks or 1P / 2P buttons. All the wires go into the 'interface board'. Could it be this thats faulty? Is this a common fault and an easy fix?

Any help gratefully received, I'm dying for a game now!

Dougie

 

[virtvic]

Possibly a grounding problem?

 

[andyman]

Click One on Feebay ending soon. Seller is a nice guy

Andy.

 

[trm]

If you want some help troubleshooting this instead of buying a replacement then just say. Although that does seem a good price for the IO board.

cheers
tim

ps Welcome to ukvac! Hope you like it here

 

[DanP]

Possible causes that I know of are;

Bad ground/missing ground on the controls (measure with multimeter)
Bad wiring to the widget board causing bad ground or low +5v (measure again)
Bad solder on the connector pins on the widget board - reflow to fix
Bad 6821 PIA on the widget - replace to fix
Bad cable on the widget board - replace to fix

Welcome to UKVAC!

Dan

 

[R177]

Hi all, thanks for all the welcomes to the site!

I did see the board on ebay, but as it was being sold as 'untested', I didn't want to risk buying a useless board, however I've just put in a bid. So fingers crossed! My cashflow is slow so I don't want to get into a bidding war!

I wouldn't know where to start fixing it myself or checking the grounds. I do own a multimeter but use it for the car only!

Dave Langley did a great job renovating all the boards a few years ago but I've neglected my Robotron of late and as I say, it's not been turned on for quite a while!

Dave lives a bit too far away for another visit (I'm near Glasgow) so I'll see if I win the auction, if not, then I'll need to try something else.

Thanks again guys.

Dougie
R1772011-08-12 14:18:18

 

[R177]

Well, didn't win, tried to up my bid in the last few seconds but missed it.

I'm going to take all my boards out and give the plugs and connections a wee clean.

I'll let you know how that goes.

 

[chadsarcade]

The coin mech controls use inputs on the ROM board, so it looks as though your problems are isolated to the interface board.

Don't overlook the obvious - the inter board connectors often make iffy connections. Re-seat the ribbon connector onto the CPU board a few times, or try to polish/clean the pins on the CPU board side as they may be tarnished. Also check the pins of the 2x10 way connectors which go to the control panel, again the pins may be tarnished. Check the solder side of these connectors for dry joints which are quite common on these connectors.

Whilst in switch test, try wiggling the ribbon or putting pressure on the connector and see if any controls register at any point. If you get something at some point, it would indicate a physical connection problem. Dan's suggestions are also very good.

Chad (quite a bit further north than Glasgow)

 

[grobda]

Hi Dougie

John Bud has a working robotron cab and he's near glasgow; might be worth sending him a PM. Or I'm in glasgow and could lend a hand checking it. I've learn a bit about williams hardware getting a joust PCB set up.

cheers

Rick

 

[R177]

Thanks Chad, I'll try all that and let you know how it goes.

Failling that, Rick I'll PM yourself or John Bud.

Thanks again guys

 

[R177]

Hi again, well, I removed the interface board, cleaned all the pins and contacts, then resoldered the connector pins on the back. Put it all back together and...it works!

Thanks for all your help with that guys.

My next concern is the monitor, an original Hantarex one (don't know the model number). It seems a bit iffy, buzzes loudly and flickers, sometimes cutting out completely, resolved only with a gentle rock of the cab! Is there a replacement that will fit straight in, ie, all the same connectors and mounting points? As I'm not too technically minded I don't want to start changing things about in there.

Oh, and, the top light behind the marque doesn't work, it has 2 wires running to it from the power unit that sits in the base of the cab, but no voltage running through them. Any ideas?

Thanks again for your ideas and advice.
R1772011-08-18 23:49:59

 

[grobda]

congrats on the fix. the monitor sounds like another bad connection, could be as simple as a power lead not being seated properly, hence it coming and going as you move the cab.

 

[R177]

Ive checked and cleaned all the connectors and plugs, all seem ok. I'll just have to live with it for now as I can't afford a new monitor. The tube light behind the marque is just annoying though!

Another project for the future is to change the microswitch joysticks for original Wico leaf-style ones. I'll keep checking ebay for them.

Still, for now.....it lives!

R1772011-08-22 17:46:38

 

[chadsarcade]

The joysticks originally fitted to those were a weird affair with a spring loaded ball bearing at the bottom of the shaft providing the centring mechanism. Rav may have a picture somewhere of one. A wico or equivalent with leaf switches would be the way to go.

As for the marquee light - not original I know but have you considered something like these:

http://www.ebay.co.uk/itm/190561670677

Nice work so far,

Chad

 

[JohnBud]

you really need to ditch those sticks. if your ever near glasgow or stirling give me a shout and i will give you a few credits on mine.

cheers.

john bud

 

[R177]

Yep, I agree John, the microswitches never last long with all the abuse they take!

Any idea where I could pick up a couple of red top Wico sticks?

I put a new striplight in behind the marquee so its lit up now

.

So, Wico sticks and new coin mechs, then I'll start thinking about restoring the cabinet and the very worn control overlay.

 

[JohnBud]

i might have a couple spare but i will need to check. where in argyll are you ??? i used to cover the west but i only do the east coast now.

 

[R177]

Cheers John, I'm in Dunoon

 

[JohnBud]

are the mackrel up yet ??? last 4 fridays i was at greenock, nobody was catching anything. ive got a village full of pensioners waiting for a free lunch

 

[R177]

Hahah, I'm not a great one for the fishing John. just not got the patience for it!