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Hi Matt, That's an interesting idea. I have cleaned the IC leads by holding the chip leads against my antistatic mat and rubbing the tarnish off with an eraser. I wonder, would tinning work if the leads are tarnished? I wonder if there's a way it could be used to re-tin the sockets? It sounds like it might be a little messy? For now, it's been 3 nights in a row I've tested my ALTAIR and it's still working. So, running the chips in/out a few times seems to have done the trick.
1 week to go until show time. Josh From: turner...@hotmail.com To: n8vem...@googlegroups.com Subject: RE: [N8VEM-S100:5709] OTish, S-100 SSM I/O Board. Date: Wed, 26 Nov 2014 19:47:39 -0500 This is even more off-topic..but here goes.
I t sounds like there is a reasonably common problem of poor contact between the IC leads and the socket. There isn't much that could be done about the sockets, but it may be possible to apply a tin plating to the IC leads. It might involve fixing a probe to half the leads at once, but I don't think the voltage could be above 1.5v, so it may not damage the chip. Is that accurate? I picked up a "wipe-on" plating kit from Caswell Plating this fall, which consists of a wall socket transformer/regulator, tin solution, and probes. Basically, you attach the anode to the piece you want to plate, the cathode is wrapped in a bit of cloth, you dip that in solution, and wipe a new layer of tin onto whatever you're trying to plate. A bit complicated, but less so than removing sockets etc. Shouldn't affect value at all, but could fry chips I suppose, even at 1.5v. Actually, you might be able to do the entire chip at once by setting it on a pice of copper plate in contact with all the leads. I guess what may make it interesting is that there are gold plating kits available as well, which would certainly improve contact. Any S-100 boards with unplated contacts could become plated fairly quickly. Is this a completely stupid line of thought? Has it been tried before? The tin plating kit was $42 cdn, so that at least is economically feasible. Regards, Matt Turner From: crus...@hotmail.com To: n8vem...@googlegroups.com Subject: RE: [N8VEM-S100:5707] OTish, S-100 SSM I/O Board. Date: Wed, 26 Nov 2014 19:00:38 -0500 Hi Guys... making good progress with my loading of Micro-Soft 4K Basic into the ALTAIR 8800. Since it's for a vintage computer show, I'm using what ever vintage boards I have. I'm using the original ALTAIR 8080 CPU board with 8K of RAM and Solid State Music IO4 board. I'll be bringing my 8080 replacement board along as "back up". Anyway, I was having a tough time with the SSM IO4 board. After reseating the chips, the problem has went away. I'm tempted to replace the sockets on the board. I'm also tempted to solder some of the TTL chips directly in the board to avoid future issues with bad socket connections. It feels wrong to not use sockets, but I have no issues removing soldered IC's (I have a professional desoldering station).
After this computer show, the ALTAIR will sit on the shelf for a long time before it's called back to action, But, do I want to be trouble shooting the board again in 6-12 months? This is all based on the belief I have that a soldered in chip makes a more reliable connection than a socketed chip. I would love to hear your opinions... How would replacing sockets and/or soldering in the chips affect the "vintage" value of the board? Cheers, Josh Bensadon -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. |