MiniMig Repair (needed INFO)

[Zetr0]

Hello there my fellow forum chummies =D


I am helping a fellow AmiBayer with his borked MiniMig.

Unfortunately a skills failure in an upgrade cause a few problems

have a read here of the original problem and have a read of the the repair log here

anyway just completed repairing the unit and was about to test before upgrading to 4MB but I noticed something on the Spartan that I am unsure if it should be there or not....


Spartan trouble

As you can see - a small blob of solder bridging two pins on the Spartan chip.


I honestly dont think it should be there and could quite likely be a solder spit or drip from a soldering iron.


Alas I dont have a reference and all my MiniMig sources are on a HDD that put up with the rest of the stuff =(

If anyone has a working MiniMig can they confirm that this bridge should or should not be there I would be appreciative =D

[mfilos]

Awesome stuff there mate. You did one hell of a job

I don't have a MiniMig but trying to see some higher definitions resolution pictures... I don't see any bridge.

[Allen1]

Hi there Zetr0,

I have just checked mine and the bridge is also there, it also appears to have a hard to see bridge to the next leg to the right ie 3 legs are joined and seems to be confirmed with my multimeter. Is the same connections on yours? mine works fine and I wouldn't have looked unless I saw this post.

[yaqube]

Originally Posted by Zetr0

If anyone has a working MiniMig can they confirm that this bridge should or should not be there I would be appreciative =D

This solder bridge is OK. The pins 54-56 are connected together. Have a look at schematic diagram for more details.

[Zetr0]

Cheers guys!!!!

that all makes sense now, 54,55 and 56 are just aux vcc inputs

really appreciate it =D

[Zetr0]

MiniMig now repaired - Thanks for you help and support guys!!!!

[Allen1]

That's good news and I really am impressed at the repair you did on the ram bridging and track/pad damage also a big thank you to yaqube for pointing out the 3 legs are meant to be linked, as I mentioned one of the bridges on mine looks like an accident rather than a deliberate joint

[Zetr0]

@Allen1

Thanks for your kinds words my friend, I will say that anyone whom's willing to put some practice in can do it =D

although I wouldn't suggest practicing on MiniMigs, perhaps something cheap and cheerfull like some PC moterboard and components

[Allen1]

@Zetr0,

I used to enjoy electronics and repairing all kinds of things in the past and I can appreciate exceptionally good work when I see it. Nowadays my eyesight is too poor for close up work and my concentration and hand coordination/steadyness is not as it was so I wouldn't dream of attempting what you have done anymore. My downfall was taking prescribed medication, its obscene the problems that can arise due to medication but that's a bit off topic.

Even when I was more capable, I would have probably lifted another pad or two removing the old ram on that board you just fixed unless I used a Pace ThermoTweez hand piece or something along those lines.

[Loedown]

Originally Posted by Zetr0

@Allen1

Thanks for your kinds words my friend, I will say that anyone whom's willing to put some practice in can do it =D

although I wouldn't suggest practicing on MiniMigs, perhaps something cheap and cheerfull like some PC moterboard and components

Dead hard drives are also great fare for practising on, you get a wide assortment of fine pitch QFP, SOIC, SOT etc. For a real challenge, you can try taking the full SMT cable header off the back using a dental pick, solder wick and an iron without lifting any pads.