68kMLA Classic Interface

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Duo display with pink lines
Posted by: PotoMac on 2022-03-06 07:09:11 I'm reviving a Duo 230. I've recapped it, replaced some bad diodes & the LT1171 voltage regulator (per a discussion in this forum that seems to have gotten lost in the crash last year). The display is fine because it works with another working Duo I have. It chimes, now that it's recapped & the new LT1171 didn't make it worse, but it goes straight to the pink lines after the chime. I have a new LT1271 as well that I haven't replaced yet. Is this the next step? Finding more bad diodes perhaps? Replacing the LT1171 was a lot of work, given my current soldering skills, so I want to make sure that replacing LT1271 is worth the effort before I screw it up entirely.
Posted by: techknight on 2022-03-09 07:46:40 Better check all the voltages coming out of the DC-DC stages to make sure they are all present. I don't know what they are since I have not worked on a Duo in a very long time. But, they have to be checked to know if the regulators are working properly or not. IF they are, then likely one of the graphics chips is bad, or the VRAM is bad.
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