Mouse move horizontal only

[Kasio]

Saved an A1200 from the dumpster and I think the previous owner got insane from the mouse only moving on the x-axis..

Is there a likely cause for this and can it be fixed?

Tried three different mice with the same result.

 

[rkauer]

Check the traces from the mouse port. Then check the TTL that interfaces the mouse port to CIA, Paula & Lisa.

 

[Bad_Ad84]

The Amiga 1200 I bought here had the same problem. Was a dry joint on one of the smds (caps/resistors). Having the schematics makes fault finding much easier

This also wouldnt be picked up by the above test, as route between chips was fine

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[Zetr0]

@Kasio

1. Check the mouse - it may be that its damaged
2. Check the port - it could be a mechanical issue
3. Replace / resolder C313 ( 0.047UF capacitor) *(a)
4. Replace U32 SMD varient of the 74LS168 (this is quite commonly the fault) *(b)


*(a) C313 is monolytic cap on the underneath of the board between the expansion port and serial port - its more likely theres a solder fault or the ceramic capacitor is phyiscally damaged than it it being faulty.

*(b) U34 is more comonly the actuall fault here, I would suggest that you re-solder the legs to ensure that theres no dry solder joint - should that fail then I suggest replacing this IC - sadly its not as common as most so eBay turns out to be a bit of a bust or I would link it for you.

I suggest to source one of these components - see your local electronics / hobbyist store has them.

 

[Bad_Ad84]

If he needs U32 (or is it 34? You mention both), I have a few. As I had replaced that first


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[Kasio]

Many thanks for all the replies.

It turned out to be just a mechanical issue: A broken pin, which was later to be found in the mouse.

Sorry for bringing in the cavalry on this one.. :roll:

 

[cosmicfrog]

ahh thats how we like em, realtivley simple

 

[AndyLandy]

Many thanks for all the replies.

It turned out to be just a mechanical issue: A broken pin, which was later to be found in the mouse.

Sorry for bringing in the cavalry on this one.. :roll:

We're just glad you managed to fix it and saved another miggy!