Hardware For Sale/Trade

In Indigo2 IMPACT TRAMs the PCB is attached to a heatsink with kapton tape, which makes it bend slightly (mechanical stress). The TRAM chips themselves are QFP chips (the type with SMD legs on all four sides). This is not a good combination. The mechanical stress combined with aging (brittle soldering joints) and/or thermal cycling results in the legs of the TRAM chips letting go.

The TRAMs themselves don't even get all that hot, compared to the large heat sink on the top board of the MaxImpact board set. Also, I've seen several IMPACT TRAM option cards gone bad, but never the "base" 1MB TRAM which comes with every MaxImpact (and which is not under mechanical stress like the TRAM option cards). Admittedly, I have seen several MaxImpacts, but not enough to make this a statically valid statement.

Octane TRAMs are mechanically better. They don't flex anymore:

I've seen MXE TRAMs which needed to be re-seated, but never had one die on me. I think if they had develop a heat sink like the one of the Octane MXE TRAM, which doesn't flex the PCB, the Indigo2 IMPACT TRAMs would have been more reliable.

MXE TRAMs also have a larger heatsink surface, but I think the Indigo2 has better and more efficient airflow in it's graphics compartment.

jan-jaap wrote: I think if they had develop a heat sink like the one of the Octane MXE TRAM, which doesn't flex the PCB, the Indigo2 IMPACT TRAMs would have been more reliable.

do you think it's possible and reasonable to redesign the heat sink ( MaxImpact Tram option) with a modern CAD/CAM process, then to provide it as "kit" or provide the full service (something like … you send me your MaxImpact card, I will replace the heat sink for you, you pay the kit and the effort) ?

I am thinking about companies like Daystar (USA), sometimes it's " Vaporware " like the news - Daystar Turbo 060 - sometimes it's the Truth. I do not know about Apple/68k, but know they offered something similar for Apple: PowerPC CPU upgrade, BGA package desoldering, chip swapping, and re soldering (with a few hack, off course, e.g. the PLL, and the Vcore), and with new heat sink design , mainly because the new CPU might need a stronger heat sink (e.g. from PPC750, 6Watt to PPC7410,12Watt). Sometimes they offer a completely brand new design, e.g. the SMP CPU kit 2x7450@2Ghz (designed from the scratch) for the Mirrored Doors PowerMAC (dual G4 1.6Ghz, the last one G4 machine before G5), but … that kid was extremely expensive (and more expensive than the cpu-swap kit) because they didn't make hundred thousand units, just thousand.

Contacting them, and buying a few CPUs from them, I did something similar (I have created a topic, just to post a few photos and comments) … the result is fine, not excellent because limited by the poor technology we used for the heat sink: we didn't use super heat-pipes (every modern laptop uses them), we just redesigned the previous heatsink and switched from aluminum to copper, and adding more copper and more "exchange surface". We didn't get the thermal resistance reduced by the magnitude that a super heat-pipe can offer, so it's not efficient, but it works!

The point I want to ask: today should be easier and cheaper, because there are more CNC and know/how: what do you think?

ivelegacy wrote: do you think it's possible and reasonable to redesign the heat sink ( MaxImpact Tram option) with a modern CAD/CAM process, then to provide it as "kit" or provide the full service (something like … you send me your MaxImpact card, I will replace the heat sink for you, you pay the kit and the effort) ?
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The point I want to ask: today should be easier and cheaper, because there are more CNC and know/how: what do you think?

I don't know much about CNC, so I can't answer that one.

But, presumably, people would best leave working TRAMs alone, so any TRAM which needs treatment has already failed. I reworked two TRAMs which cost a *lot* of time, and had a 50% success rate. If I had to put a price on it, it would certainly be a rather hobbyist-unfriendly amount of money. If I had the time in the first place of course, which I don't. I have a job, a family and a hobby which consume all my time already

I rather doubt there's enough of a market for TRAM repairs to make this an interesting opportunity for a business.