Weird screen problem with 6th gen ipod

[Frankenpod]

This isn't really a Rockbox issue, though it does relate to RB in a way...

Have a 6th gen (I think, or it might be a 120GB 7th gen logic board) ipod classic with RB installed on it.  The weird thing is the screen doesn't work if I boot in original firmware or disk mode - it comes out whited-out/blank.  Yet it works fine in Rockbox mode.  Was wondering if the original firmware was corrupted or something, so restored it, and now it doesn't work at all (as RB has now been removed), comes out still whited-out.  Suspect if I put RB back on (PC can still 'see' the drive when connected) it will go back to working only in RB mode again.

Anyone have any idea why this would happen?  Seems _really_ odd to me that RB can drive the display correctly while the OF can't.  One thought is that maybe iTunes is for some reason restoring it with the wrong firmware version (not sure if this logic board is a 6th gen or a 7.0 gen originally, iTunes seems to think it wants 2.0.1 version firmware).

[iPodVT]

Have a 6th gen (I think, or it might be a 120GB 7th gen logic board) ipod classic with RB installed on it.

If Rockbox classifies the iPod as an ipod6g (and if/when the iPod's screen is working), you should be able to determine the exact model via System->Debug->View SysCfg.

The weird thing is the screen doesn't work if I boot in original firmware or disk mode - it comes out whited-out/blank.  Yet it works fine in Rockbox mode.  Was wondering if the original firmware was corrupted or something, so restored it, and now it doesn't work at all (as RB has now been removed), comes out still whited-out.  Suspect if I put RB back on (PC can still 'see' the drive when connected) it will go back to working only in RB mode again.

I have tried both an 80GB 6th Gen and a 120GB 7th (aka 6.5) Gen with Apple firmware v2.0.4 PC by swapping in pre prepped storage and didn't have any screen issues (though both were unstable in other ways so I abandoned that hack).  Can you try swapping your problematic iPod's storage into another iPod of the same model and vice versa?

Also, did you try reseating the LCD's flex and/or using a different known-working LCD?

[Frankenpod]

Well this has gotten stranger still.  I actually have two ipods with this same issue.  The second one I tried flash modding with a 512GB card (figuring I had nothing to lose with this weirdly-behaving thing), and weirdly, it restored in iTunes, stating 460GiB size, while simultaneously declaring it had firmware 1.1.2 (two attributes I didn't think could co-exist).

  I was then able to install rockbox on it.  It still has the problem that the screen is blank in original firmware mode, but it seems to function with RB, with 460GiB available, and I can synch to it in OF mode (albeit can't see what it's doing).  System debug syscfg says model number mb147, and last three letters of the serial number are YMV, but I can't work out from that if it's a 6th gen or a 7th gen or a 7.5gen.

It's possible in all my endless faffing about with broken/refurbished ipods I've swapped some parts around at some point, but I didn't think I had any 7.5gen logic boards spare.

I don't have any working screens to swap in, and anyway, the puzzle is why the screen works with RB, but not OF.

Edit, hmmm, according to something I found about decoding serial numbers, this one was made in 37th week of 2007, so it would have to be a 6th gen (which is what I thought it was).  Odd that it seems to accept 512GB, but I think maybe I somehow, entirely accidentally, have done the same firmware swap thing you did, but for some reason it has the side-effect of the display not working in OF.  Though even that doesn't entirely make sense as I restored this thing from fresh with the flash memory mod.

Pah, am inclined to give up and consider it a mystery.  Can't work out what's happened to these two ipods.

[iPodVT]

Yes, that is very strange.

A 512GB card should yield ~477GiB.  What kind of storage are you using (make/model of adapter/card or SSD)?  Did you test it with H2TestW when it was new?

Model MB147 and serial ending in YMV both indicate a black 80GB 6th Gen, so firmware 1.1.2 is expected, but not with more than ~127GiB allocated storage.

[Frankenpod]

Oh, the 460 figure makes sense - that's what I've repeatedly found "Integral" brand 512GB cards (such as this one) come out as.  Other brands seem to get to the 477 figure.  It's not fake, as it's been used repeatedly in modded ipods (is one I swapped out of another ipod when increasing the storage of that one)

To complicate things further, this is using an iFlash quad that I've left unused because it seems to itself be faulty (has strange blemishes on the finish of the underside, and every ipod and every card I've tried it in it's run into corruption problems when synching - I suspect it's a manufacturing fault - was going to return it but couldn't figure out how to do so and left it far too late to get round to it).

  Was just trying to make use of all the problematic components I had left over!  This one has now hit problems with synching, but don't know if that's because of the weirdness with capacity vs generation/firmware or if it's just that dodgy iFlash doing its thing again.

So I now have two weird ipods, one with a generic flash adaptor and 128GB, that reports 2.0.1 firmware, and has a blank screen in OF mode but seems to work in RB mode.  And one with the dubious iFlash quad and an integral 512GB card, that at least briefly worked apart from also having the blank screen in OF issue, and reported a seemingly incompatible 1.1.2 firmware and 460GB capacity, but now keeps corrupting when synching.

Wish I'd taken a screenshot of iTunes reporting simultaneously 460GB capacity and 1.1.2 firmware.  Really doesn't seem as if that should have been possible.   And why would screens work with RB but not in OF mode?  Does RB basically rewrite/replace even the low-level 'display driver' stuff in the firmware?

[Frankenpod]

Got a fresh iFlash (replacing the one with odd blemishes on the reverse) and now it seems to work.  Sort-of.

  Actually upgraded it to about 1.5TB (using up every spare micro SD card I had lying around), and, while it won't restore with iTunes (iTunes just fails to acknowledge that it's connected at all - couldn't seem to "see" it) and the screen still comes out totally blank when booted in original firmware mode; after using AOMEII to format it to FAT32 (and deleting the very small extra partition it saw at the start of the drive - I'm wondering if it was the one the Original Firmware resided in?) rockbox succesfully installed, and when in RB bootloader mode it succesfully syncs.

Still mystified as to what exactly this thing is doing.

The downside is synching in RB bootloader mode is horribly slow - even slower than synching in original firmware or disk mode on a 7.5gen (it takes about 45 hours to do a full initial synch even in OF mode on a 7.5 gen, this took even longer).

When booted in RB mode it seems to work fine, despite being a 6th gen with > 1TB storage.  The puzzling thing is, even if I force it to boot into OF mode it doesn't corrupt, just comes up with that whited-out screen but goes back to working once rebooted in RB mode.  Not that I want to risk testing that repeatedly.