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Vectrex turns off or freezes when the joystick is pressed

>>> 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
Damn! So i have bad file :(
 
Strange....doesn't exist any Vectrex bios including Minestorm game on internet :(
 
Dave, Minestorm.vec 8k file it's correct... i burned it on W27c512 eprom and Vectrex
powered on normally with the Minestorm game....Unfortunately i have always same problem :((((((
 
Oh well, it is still a very useful data point on the problem...

Let's look at this logically...

The CPU must be OK (it runs cartridges OK).
The 2114 RAMs are likely to be OK (if the cartridges don't have any internal RAM, then they will be using the Vectrex RAM).
The 6522A must be OK (this has more to do with the video circuitry than the games controllers).
The AY3-8912 is the device that receives the controller buttons. However, the potentiometers go via the multiplexer IC (4052B) on one of the OPAMPS driving the COMPARE signal - and have nothing to do with the AY3-8912...

Let me have a think...

Dave
 
Good evening Dave, do you have a good idea to solve this problem please?? :(
 
Simple answer - no.

We need some more data points I am afraid. In particular, can we see any disturbance on any of the key CPU lines when the problem occurs?

Pin 2 (/NMI).
Pin 3 (/IRQ).
Pin 4 (/FIRQ).
Pin 40 (/HALT).
Pin 37 (/RESET).
Pin 34 (E).
Pin 21 (A13).

Monitor the CPU pin and 'play with' the controls until the fault occurs and see if there is any difference in the signal associated with the CPU pin before and after the fault occurs.

This will be an iterative issue (in that we may have to monitor further signals depending upon what this investigation reveals).

I am expecting the CPU to 'crash' and stop executing instructions. Let's see if this happens shall we?!

What we are trying to find is the 'cause and effect'.

Dave
 
Simple answer - no.

We need some more data points I am afraid. In particular, can we see any disturbance on any of the key CPU lines when the problem occurs?

Pin 2 (/NMI).
Pin 3 (/IRQ).
Pin 4 (/FIRQ).
Pin 40 (/HALT).
Pin 37 (/RESET).
Pin 34 (E).
Pin 21 (A13).

Monitor the CPU pin and 'play with' the controls until the fault occurs and see if there is any difference in the signal associated with the CPU pin before and after the fault occurs.

This will be an iterative issue (in that we may have to monitor further signals depending upon what this investigation reveals).

I am expecting the CPU to 'crash' and stop executing instructions. Let's see if this happens shall we?!

What we are trying to find is the 'cause and effect'.

Dave
Hi Dave, ok i can try these measures... This Vectrex mounts two 2114 Ram ics....can i try to unsold and change maybe?
 
As I have stated before, I can't see how the 2114 RAM is faulty if the machine works with a different ROM cartridge installed (as that cartridge ROM should be using the same RAM - unless the cartridge contains its own RAM of course).

If you are not careful with exchanging devices, you could change them all and still end up with a faulty machine! This is why I prefer to think and investigate rather than to start wielding the (de)-soldering iron...

Dave
 
Simple answer - no.

We need some more data points I am afraid. In particular, can we see any disturbance on any of the key CPU lines when the problem occurs?

Pin 2 (/NMI).
Pin 3 (/IRQ).
Pin 4 (/FIRQ).
Pin 40 (/HALT).
Pin 37 (/RESET).
Pin 34 (E).
Pin 21 (A13).

Monitor the CPU pin and 'play with' the controls until the fault occurs and see if there is any difference in the signal associated with the CPU pin before and after the fault occurs.

This will be an iterative issue (in that we may have to monitor further signals depending upon what this investigation reveals).

I am expecting the CPU to 'crash' and stop executing instructions. Let's see if this happens shall we?!

What we are trying to find is the 'cause and effect'.

Dave
I tryied to check these pins but with this scope i can see waves....i see signals and the only that seems to be change when vectrex freeze is on pin 21 :(
 
Not sure what you are saying...

Most of these signals (under normal operation at any rate) should be permanently HIGH (for example, pins 2, 40 and 37). These signals shouldn't have waves on them.

If pin 21 (A13) is changing state (between working and non working) what is it changing from and what is it changing to?

Dave
 
Dave im desperate!
I tryied to change the two ic rams but unfortunately two tracks torn up :(
I solded the two little copper hair and i solded the 2 new ics but now i have black screen :(
Today i buy the ram socket and i try to repair :(
 
This is why I don't like replacing components at random because of the potential damage to vintage PCB tracks etc.

There is a high probability of "cause and effect", so the (new) fault is highly likely due to the work that has just been performed. So, you need to get the machine back to the previous state.

Don't forget that this is a two layer PCB, so some of the damaged PCB tracks can go through vias on the board - which may be the through the pins of the RAM. This is a job for your multimeter to check for continuity where there should be continuity and no accidental short circuits where there shouldn't be any. Multimeter set to resistance and the circuit diagram and a highlighter pen in your hand as you check the various segments of PCB track out.

Dave
 
This is why I don't like replacing components at random because of the potential damage to vintage PCB tracks etc.

There is a high probability of "cause and effect", so the (new) fault is highly likely due to the work that has just been performed. So, you need to get the machine back to the previous state.

Don't forget that this is a two layer PCB, so some of the damaged PCB tracks can go through vias on the board - which may be the through the pins of the RAM. This is a job for your multimeter to check for continuity where there should be continuity and no accidental short circuits where there shouldn't be any. Multimeter set to resistance and the circuit diagram and a highlighter pen in your hand as you check the various segments of PCB track out.

Dave
Hi Dave, happy Eastern!
Not...i repaired wires on the board but i have always black screen...
I don't want to waste any more time on this console, so I'll probably sell it to an interested friend ... he'll fix it;) I'm waiting for a new cbm pet 8032 to be fixed with dual drive and I have to start replicating a Galaksja. Do you know the Yugoslavian Galaksja computer ??
 
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