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Vectrex turns off or freezes when the joystick is pressed

Desperado

Desperado

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Nov 25, 2017
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Hi guys, this is my second Vectrex console which needs to be repaired :(
This other Vectrex is different ... it is not from MB but from GCE ... it seems to have been modified by the factory to operate at 220v. Instead of the plug it has a kind of transformer. If i turn on it seems to work but when i press or i move joystick she freezes (on video).
Please any help is appreciated!
Thanks!

 
Why don’t you try the diagnostic cartridge on this machine to rule out a ROM fault?

Using the joystick (whilst the diagnostic cartridge is running) should not cause problems. The diagnostic cartridge should contain a test for the joystick interface itself.

If I remember correctly, you have used your other joystick on this machine with the same results haven’t you?

After that I would check the joystick connector on the Vectrex and PCB tracking for signs of damage, bad solder joints and potential short circuits.

Try each button on the joystick in turn to identify if the problem is associated with one, more or all buttons. Does moving the joystick X and Y have any effect? You need to identify repeatable patterns in the data.

After that, you are into chip replacement. IC208 is an AY3-8912. This chip is responsible for the sound (which seems to work) and an 8-bit I/O port (for the four buttons on each joystick).

Is the problem associated with one or the other joystick, or both?

The RIGHT button of each controller is handled by the Vectrex in a slightly different way - hence the interest in whether your problem is associated with a specific button(s) or not.

Dave
 
Hi Dave how are you?
The new ic is arrived today! I inserted in this Vectrex and (naturally) i have always same problem..
I inserted test cart but the problem is random ... sometimes it happens when I press a key, sometimes if I move the lever or if I press another key. Even with the other joystick it's the same! If i use Joystick test seems to be ok... :(
 
Ah,

So this machine fails randomly whenever you press any of the buttons OR move the joystick.

Is that correct?

Dave
 
Hi Dave,
with test cart inserted, if i press any joy button or i move stick nothing happens, everything seems to be fine...without test cart if i move stick or i press any button the screen goes black and no sound is heard ... if I press the reset button, everything turns on again.
 
Update:
If in insert any cart game, i have no problem even if I press the joy buttons!
it only happens with the game built into the Minestorm console :(
Why?
 
>>> Minestorm game is installed on IC201?

According to my schematic yes. There should only be one (1) ROM on the logic board.

Dave
 
You're always desperate my friend :)...

A few options for you to consider:

1. We don't actually know whether the Vectrex 2363 ROM itself is faulty. This is my "best hunch" at this point in time based on the observable facts you have posted.

2. You can do nothing. You won't be able to use Minestorm - but (if you plug a cartridge in) you say it works. The worst-case scenario is that some games cartridges may use the existing ROM code for part of their support (rather than driving the hardware directly) and these may not function as desired. If the ROM does have a bit of 'bit rot' then it could get worse over time.

3. Find a replacement Vectrex ROM. This will involve contacting various groups and/or individuals on Vectrex-specific forums to see if anyone has a 'donor' ROM. Replace yours with theirs. Hopefully, this should give you a working system?

4. Replace the Vectrex 2363 ROM with a more modern device. If you look at the schematic diagram - and draw the pinout for the 2363 - you will observe that 13 address lines are wired up to it (A0 to A12). This means that the ROM is 8KB - and has 28 pins. Looking at the pinout for the 2764 EPROM - you will find it to be identical! Hence, downloading the ROM code for the Vectrex ROM (from the internet) and burning it into a 2764 EPROM should give you a viable replacement. The only pin that appears to be a bit strange is pin 26 (identified as NC - No Connect). Vectrex have wired this to +5V/VCC. You may want to bend this pin of the EPROM out at 90 degrees (so it doesn't make contact with the +5V/VCC when you insert it into the socket that you should use when you remove the existing ROM).

There you are - pick your poison...

Dave
 
daver2 said:
4. Replace the Vectrex 2363 ROM with a more modern device. If you look at the schematic diagram - and draw the pinout for the 2363 - you will observe that 13 address lines are wired up to it (A0 to A12). This means that the ROM is 8KB - and has 28 pins. Looking at the pinout for the 2764 EPROM - you will find it to be identical! Hence, downloading the ROM code for the Vectrex ROM (from the internet) and burning it into a 2764 EPROM should give you a viable replacement. The only pin that appears to be a bit strange is pin 26 (identified as NC - No Connect). Vectrex have wired this to +5V/VCC. You may want to bend this pin of the EPROM out at 90 degrees (so it doesn't make contact with the +5V/VCC when you insert it into the socket that you should use when you remove the existing ROM).
Click to expand...
Hi Dave! eheh yes i'm desperate ;)
This is (for me) the best solution and the easiest also...unfortunately at the moment i don't have this eprom...i have some 2732, 27512 and 27c020 eproms...but i can buy a new one. I have read also this forum:

www.gamoover.net

vectrex qui bloque sur joueur 1 - Page 2

vectrex qui bloque sur joueur 1 - Page 2
www.gamoover.net

What do you think about it?
 
>>> What do you think about it?

It's all in French?! If it was German I would be OK...

A 2732 is no good - it is too small.

A 27512 would be OK. The additional address lines (A13=pin 26; A14=pin 27 and A15=pin 1) are all pulled up to +5V/VCC in the Vectrex. As a result you will either:

1. Need to program the Vectrex 8K ROM contents in the top 8K of the 64K 27512 EPROM or
2. Program eight (8) copies of the Vectrex 8K ROM contents throughout the full 64K 27512 EPROM.

If it was me, I would go for option 1 (being less work).

Dave
 
It depends on what EPROM programmer you have of course...

With mine, I just tell the EPROM programmer to load the data based on an offset I tell it. If all else fails, read the manual...

Dave
 
Ok Dave, i founded Vectrex firmware (4k) but is a .vec file....Must i rename in .bin maybe?
 
>>> Ok Dave, i founded Vectrex firmware (4k) but is a .vec file....Must i rename in .bin maybe?

Where did you find it? It should be an 8K image I would have thought. I think there maybe the EXEC firmware available without the Minestorms game though.

A .vec file is normally a graphics file not a ROM image...

Dave
 
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