Seeking repair help! *Solved*

[aerworuld]

Well met all,

My AMX mouse that I use every day for artwork on the Electron has packed up!

Over the years, I had to open it up and fiddle diddle to get it working again (usually the wiring where it enters the mouse itself has broken) but this time I can't sort it.

The mouse just runs to the right of the screen but I can't find a short or anything.

Would anyone be willing to give it a fresh set of eyes?

I'm kind of lost without it

Stuart

[Elminster]

You said in the other thread that the mouse is plugged into a smally mouse which is then plugged into an EUP.

Just wondering if it is possible to prove it is the mouse? I am guessing you are Electron only, and cant plugged smallymouse into a beeb to test? And you already said that you could only ever get that mouse to work with smally mouse, which is a bit odd as I had USB mice working with Electron without issue. Do you have a PC that the mouse will plug into to test as well.

I often think on thing is broken and it is somethign compeltely different.

Edit: Assume you must have a multimeter.

[aerworuld]

Ah no, the AMX mouse is the old style mouse from the 80's that plugs straight into the User Port.

I bought the smallymouse usb adapter as a backup after the AMX mouse started to play up the latest time, so i dont think that has affected the functionality of the User Port itself. I don't have another machine I can test the mouse on, but I do have a multi meter so I will have another bash at the AMX mouse and see if i've missed anything

[Elminster]

Could you smallymouse issue be the same as I have where I have to start AMX first then plug in smallymouse or it hangs (or in your case doesnt work with other mice). Just a thought.

[1024MAK]

Stuart

I think I have an AMX mouse somewhere, but it's likely in storage

However, the principles are not too hard to understand.

There are two signals for left / right, and two signals for up/down. I don't know what AMX called these signals, so I will call them X1, X2, Y1 and Y2.
So when you move the mouse in one direction, let's say left to right, X1 will pulse, then X2 will pulse. This sequence continues as long as you move the mouse. If you move it from right to left, X2 will pulse followed by X1. A similar thing happens with Y1 and Y2 in the up/down direction.

Assuming it has been cleaned. Apart from broken wires, poor connections, and cracked/dry jointed or broken solder connectons, the next most likely fault, is either one of the LEDs or one of the phototransistors having failed.

Can you take it to bits and take a photo of the PCB from both sides please.

Mark

[aerworuld]

Stuart

I think I have an AMX mouse somewhere, but it's likely in storage

However, the principles are not too hard to understand.

There are two signals for left / right, and two signals for up/down. I don't know what AMX called these signals, so I will call them X1, X2, Y1 and Y2.
So when you move the mouse in one direction, let's say left to right, X1 will pulse, then X2 will pulse. This sequence continues as long as you move the mouse. If you move it from right to left, X2 will pulse followed by X1. A similar thing happens with Y1 and Y2 in the up/down direction.

Assuming it has been cleaned. Apart from broken wires, poor connections, and cracked/dry jointed or broken solder connectons, the next most likely fault, is either one of the LEDs or one of the phototransistors having failed.

Can you take it to bits and take a photo of the PCB from both sides please.

Mark

Hi Mark,

I've fixed it!

I was taking back apart again to get the photographs and it occurred to me the check the wire further back from the mouse to the plug and I found a hairline crack that must have been shorting some of the wires. They are so thin I'm not surprised.

I reckon it must of happened the last time I had stripped it back to rewire it; it often fails at the mouse end (must get some stress there).

Considering it's used every day and the fact it must be getting on for 35 years old it's doing alright

Sorry to waste your time peeps!

[1024MAK]

Good, the only mouse to have is one that works

Mark