I see nothing more wrong with swapping boards than with swapping chips, fundamentally. If I have a machine with a blown cg6, I pull it and pop in another, problem solved. (I have enough spare cg6s that I do not expect to run out in the foreseeable future.) Most of the criticisms of boardswapping I've seen have actually been against *blind* boardswapping, against easter-egg swaps in the hope that they'll perturb the symptom out of immediate existence. I agree that that is, at best, a last resort - but I see nothing wrong with swapping out a bad board, once you're sure it's the board that's bad, any more than I do for any other swappable piece. (Whether it's worth repairing a board depends on lots of things; sometimes, swapping and tossing the bad one is a right answer.) /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

True. But I don't need to *fully* test the board in order to reach a sufficient level of confidence that that board is what's at fault. But for that matter, to fully test a *chip* is a lot of work, especially if you're trying to test it in-circuit. I'm not sure you can ever be truly certain; after all, your test equipment could have developed interesting flaws of its own. It's just a matter of reaching a sufficient level of confidence to risk applying a fix - trading off the risk that the fix will be wrong against the resources you would have to invest to reduce that risk further. For me, that point is often reached quite quickly. I should have said "once you're sufficiently sure". Well, a lot of the boards I deal with don't even *have* more than 2 or 3 components, unless you count etch runs and connectors as separate components. Except it often isn't, for me, as in my example of the cg6. I don't have the equipment - nor skill to substitute for the lack of it - to replace, say, the Bt458 on a cg6. Nor do I have spare Bt458s, except on other cg6s. But I do have plenty of inract cg6s. Not to say that that's always so. I have some HP-IB gear that I suspect has a blown driver on one of the HP-IB lines. Someday when I scrape together the round tuits I'll poke around - probably here among other places - looking for the information I'd need to track it down and replace it. (Fortunately that stuff is relatively low-density through-hole work, stuff I feel much more competent to do component-level repair on than modern high-density surface-mount.) /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

In article <m1F26Vr-000IyFC at p850ug1>, ard at p850ug1.demon.co.uk (Tony Duell) writes: Yeah, I have considered that too. Being lazy, I would probably opt for swapping out a board with a bad component before I would try to repair/replace the individual component. For instance, I have some spare Lilith boards, including one marked "bad", but given that boards for these machines are so rare, I am not going to chuck the board marked "bad" in case it comes in handy for a future repair. -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

In article <m1F2FXe-000IyFC at p850ug1>, ard at p850ug1.demon.co.uk (Tony Duell) writes: For stuff I have, its more likely that I would be able to find a replacement board than a replacement chip. <shrug> A board swap is a repair I can do (obviously I have to have a spare board). A component debug/replace is not something that is easily within my grasp. Which would make you sadder: that I swapped a board, or that the machine became dysfunctional and never ran again? -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>