4 replies to this topic

[jasonbar]

Long story short--does anybody know what part number or resistor value to use for the 2 variable pots on the Vectrex controller PCB?


Long story long:


So, I was on the hunt for a donor Vectrex with a good back shell to replace the back shell in my good Vectrex. I'd absent-mindedly drilled a hole in the back shell for the pause switch instead of drilling the hole in the front shell. That will teach me to drill & talk on the phone at the same time...

So, I got a beater off of eBay & have it *almost* all fixed up:

Feeling bold after fixing my clothes dryer yesterday (faulty door switch), I adjusted the monitor, reflowed the solder on the accessible IC30X chips to clean up slanty text, & cleaned off the exterior gunk.

The catch is the controller. WOW. This guy took a big screwdriver & started prying apart the 2 halves until the sides were gone, the front was gone, the PCB was in 2 pieces, the PCB location pins were snapped off...I've fixed all of those issues...but...

...most importantly, the 2 little pots (trim pots to zero the big joystick pots, methinks?) on the PCB are all but obliterated. I get almost normal vertical joystick response, but the joystick is stuck on far right, horizontally. I swapped the wires on the stick pots & it appears that both stick pots are good (and return to center & the stick has its handle--hooray!).

Has anybody got a part number or supplier or description for the 2 tiny pots on the PCB? At least I assume they're pots based on what remains. Anybody got spares?

Pics (I'll take more later, showing the extent of the disaster): http://s242.photobuc...rnolab/vectrex/

If I can't find these parts, I suppose I could consider parting the stick out, since it has many other good parts. That's probably more profitable, but I like the challenge of fixing the stick (maybe I can glue on some plastic panels to reconstruct the walls?) & I do plan on selling the system, so it would be nice to have a working (albeit hideous) controller to make the package complete.

I suppose that, if I do part out the controller, it has the following good items that I'd sell for $5 each + shipping: cord w/ connectors on both ends, stick shaft, buttons & rubber button underlay (trimmed slightly on one end to accommodate my PCB rescue surgery), & joystick assembly (pots & springs & threaded shaft, not the "bat").

Thanks!
-Jason

[boxpressed]

Hi. Thanks for responding to my other post about the XY pots, and I wish I could help you here. If you decide to break up the controller, I could use the joystick assembly. Thanks!

[Stephen Moss]

jasonbar, on Sat Jul 16, 2011 8:47 PM, said:

Has anybody got a part number or supplier or description for the 2 tiny pots on the PCB? At least I assume they're pots based on what remains. Anybody got spares?

Looks like the wipers have been removed, if the track has not been damaged then you should be able to measure the resistance value with a multimeter (DVM) across the back two leg.
Once you have the reistance value any horizontal preset potentiometer (aka trimmer) should do, some have three equally spaced pins (equalateral a triangle aligment) those shown are the other type where the wiper pin is spaced a little farther out. Those shown are referred to as "skeleton" type, so called because you can see thier internal structure but you can use non skeleton types as a replacement, they work just the same.

If you can not measure the resistance they are probably either 5K or 10K as those are the most commonly used values so try one of those, 0.25 Watts will probably be the power rating.

Edited by Stephen Moss, Mon Jul 18, 2011 1:47 AM.

[jasonbar]

Thanks for the input. Just got an answer on r.g.v., quoted below.

I ordered some cheap replacement pots from eBay--I think they're coming on the slow boat from Hong Kong, so I'll report back in a few weeks, after I've received them & fixed the controller.

Thanks,
-Jason




The Vectrex service manual states that these are resistors are Vectrex
parts R602 and R604
The details for these resistors are that they are semi fixed resistor
(horizontal type)
10K ohm +/-10% 0.125W

They are just used to fine adjust for X and Y outputs with respect to
when the joystick is abosolute centre (0v).

You don't necessariy need to find new pots of exactly the same
mechanical dimensions as the old ones, and you should be able to find
electrically equivalent ones.

I did a quick search on US ebay and found

http://cgi.ebay.com/...RN-3362-3362...
which should be electrically compatible.

VectrexMad!

[jasonbar]

Well, I've resurrected another Vectrex & controller. Zombie Vectrex!

I failed to get many "before" pictures--I have just the 2 from the auction. But, looking at the "after" pictures, you can get an idea of the extent of the damage...

http://s242.photobuc...trex/?start=all

I repaired the circuit board by jumpering all broken connections & installing replacement 10k joystick-zeroing pots. I then fashioned replacement PCB-locating pins from a pair of 4-40 button head cap screws so that the PCB would align with the buttons.

I had to rebuild much of the controller housing. It was shot, so I trimmed away some more material to remove the jagged edges. Then, I turned to my electronics/industrial/robotics hoarder friend (hoarder in a healthy way!) & he hooked me up with some VHS tape housings. Oh boy, the hinged flap on a VHS tape is aaaalmost wide enough to act as the front of the controller. What a tease! I ended up using 2 VHS hinged flaps & cutting each to a little over 50% of its length, & then bonding them with some backing material to support them. I also fashioned controller sides from VHS tape flap parts. Then, it was a bit of dremeling, filing, & fussing to get the controller to mate into the system & flip up & latch (though it's a little fussy with the latching--I think the cord has a funny kink in it & gets bunched up & gets in the way). After it was all good, I put hefty fillets of JB Weld on all of the inside seams to reinforce the joints. The controller actually looks stock at a glance & is comfortable to use!

The console was in better shape--it has an address engraved into the side by the cartridge port, it has a hole in the top right side of the back shell (currently filled with a button head cap screw), and now the monitor is all tuned in & sweet with pretty straight letters & almost no ripple.


So, I've now got a 100% working Vectrex with some character & a custom controller & a Star Trek cart for sale. What's a fair price? $100 + shipping?

Any offers? I'm in USA 91107.


Thanks!
-Jason