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Noobie help - repairing damaged traces 130XE RAM


Xebec
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OK - noobie mistakes - I was desoldering/removing extended RAM from my 130XE in order to replace with sockets and fresh RAM.. I inadvertently cut 2 or 3 traces on the top of the board while jimmying the RAM chips off the PCB.

 

Do I *need* to do a formal trace repair for something like this, or can I get away with cleaning the board, and then running some kind of thin wire between the points that the trace covered?

 

Example: Address line 5 (pin 10) is disconnected from U33 to U32, and from U32 to U31, but works the rest of the way down the line.

 

I am thinking I can carefully solder short insulated wire on the back of the PCB after the sockets are installed, and test traces before plugging in RAM/powering on?

 

And sorry for really dumb question - what gauge / type of wire should I use preferably? is stranded OK?

 

The 130XE still works OK, just with 64KB only for now..

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you can, its fiddly replacing traces with wire, I prefer solid core, usually wire wrap 30g if I have to jumper from one end of a broken trace to another

 

if your going from a component lead to another component lead standard 28g ribbon cable is fine and readily accessible to anyone that has a stash of computer parts around

 

liquid flux helps as well, my standard issue with ribbon cable wire is to strip a bit, flux it, tin it, then where its going flux and tin the pad / pin with some fresh solder, then melting the two together

 

another option is telephone or network cable, as long as its not that ultra flexible stuff where its really just a thin copper coating over nylon string (snes controllers also use that crap, ask how I know)

Edited by Osgeld
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you can, its fiddly replacing traces with wire, I prefer solid core, usually wire wrap 30g if I have to jumper from one end of a broken trace to another

 

if your going from a component lead to another component lead standard 28g ribbon cable is fine and readily accessible to anyone that has a stash of computer parts around

 

liquid flux helps as well, my standard issue with ribbon cable wire is to strip a bit, flux it, tin it, then where its going flux and tin the pad / pin with some fresh solder, then melting the two together

 

another option is telephone or network cable, as long as its not that ultra flexible stuff where its really just a thin copper coating over nylon string (snes controllers also use that crap, ask how I know)

 

OK - Good tips and i'm lucky enough all of the broken tips have easily accessible component leads (it's literally just connecting ram chips to each other), so I should have access to both the top and bottom of the socket to tap from..

 

I need to go buy some flux anyway to make installing these sockets easier, so I'll go down your suggested path. thanks much!!

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I look for via holes close to where the trace was cut and put one end of the wire into it and the other end into the socket for the IC. Try to keep the wires about the same length as the cut trace. For timing purposes. However,

as slow as 8 bit Atari's were, it's not that critical. And Osgeld is right on with #30 wire wrap wire. That's what I use too.

 

DavidMil

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Not sure of the gauge I'm using but it's bare solid core tinned

and half the width of the trace. I scrape the trace at least

1/4 inch in length down to bare copper, and tin that. Pull

the wire until it's perfect straight and cut to size with

maybe enough room to go into a via if needed at the broken

end. When the melted solder latches onto that wire it will

pull dead center of the trace like magic and your repairs

look like they were factory ordered.

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