Power Mac 5400 video issues

[LazarusNine]

Hello! So, I recently hastily bid on (and won) a Power Mac 5400 that is exhibiting video issues. I suspect that the analogue board and motherboard need recapping; this solution has generally worked for me so far and resulted in working Mac SE/30s and other compacts. However, does this look like more than a recapping job to you? What are your thoughts at first glance? Any advice would be appreciated!

 

[just.in.time]

I would reseat any vram and cables running between the logic board to analog board to crt first.

Also, sweet black 5x00 series i really want one, but they seem pretty rare in the US.

 

[techknight]

Yeap, thats a logic board fault. Probably VRAM. 

 

[LazarusNine]

Yeap, thats a logic board fault. Probably VRAM.

Alright. Thanks (both) for the replies. When it's in my hands, I'll have a little exploration and start with re-seating things and see where we get to.
If the VRAM is shot, that might be an issue, as I thought it was soldered. However, this image from the Apple service manual makes me think it's slotted? Guess I'll find out soon enough!

 

[just.in.time]

That service manual should also inform you if both need to be populated with identical vram Simms or if you can operate one empty at a reduced bit (8bit Color vs 16bit color). I know most 68k Macs that had 2 slots need identical sticks (lc575 comes to mind), but can't recall on the PowerPC (I used to have a 5500 aio but it's been a while). In any case, if it can run with just one and reseating them and the relevant cables/reinserting the logic board doesn't fix it, try running just one at a time.

If that doesn't do it (or it can't run with one), you can always order a new pair of Simms. Beyond that you're looking at deeper troubleshooting. Techknight will know more in that area.

 

[LazarusNine]

Yeap, thats a logic board fault. Probably VRAM. 

The 5400 arrived today and I had enough time to extract the logic board. I've not seen this kind of configuration before; Apple really packed stuff onto this one. Unfortunately, there are no VRAM DIMMS. All of the VRAM must be soldered onto the logic board. There's video input, PCI, ethernet COMM slot (?), a cache slot and the two DRAM slots (amongst other things). Interestingly, a second slot, which I thought would have been populated by VRAM is missing from the board completely. Hopefully the pictures should provide some clarification. Any idea where to begin? Is this still a logic board issue or perhaps an analogue board problem? Thanks!

 

[Byrd]

I'd clean the edge connector (both on the motherboard itself and the Mac); you also have a video out board to connect an external CRT to for better troubleshooting

 

[Trash80toHP_Mini]

From the ThinkClassic reply I just posted:

Looks like you've got an external (mirroring only?) display cable/connector option installed. Hook one up and use it as a test to see if it's a logic board or AB issue?

edit: what the heck is that white block on the ComSlot card? I'd assume so, but did you pull that card a/o the video setup to see if either is the problem? The tuner card messes with video big time.

 

[LazarusNine]

Cheers, Trash! Guess it's not the analogue board!



I did notice a little bit of battery residue - not sure if it's enough to be a contributing factor.

 

 

[Trash80toHP_Mini]

Cool! Next step in the degub process will be to do a screen shot/video memory dump testing whether it's VRAM related or not. Hopefully you can see just well enough to copy the file onto floppy. If that comes up as a clean desktop image, you can scratch VRAM issues off your checklist.

The double image (Portrait Mode scrunchup variety) on the mirrored display lends some credence to the borken/really flaky trace connection theory. The battery/mirror video header connector area is where you noticed damage, no?.

 

[Trash80toHP_Mini]

If the VRAM is shot, that might be an issue, as I thought it was soldered. However, this image from the Apple service manual makes me think it's slotted? Guess I'll find out soon enough!

Not slotted, IIRC the empty pads are for a ROM DIMM next to the Cache slot. Got DevNote?

edit: me has serious jealous, that looks like Black ABS? :O

 

[LazarusNine]

edit: me has serious jealous, that looks like Black ABS? :O

Ha! Yes, it's black. Came with the black keyboard and mouse as well, though they need some serious cleaning.

Thanks for your help so far. I've done a pretty thorough cleaning job of the logic board with a variety of methods. I'm letting it completely dry at the moment before making further moves.

Yep, I noticed the damage near the display mirroring connector as well. That's been thoroughly cleaned up. I'll probably get some caps on order soon so I can eliminate those as contributors (they need replacing anyway, though I don't see any visible leakage around any of them).

We'll continue this investigation! Thanks for your interest. It helps to have another mind on the matter.

 

[Trash80toHP_Mini]

De nada, this is some of the fun stuff! You wouldn't have a PCI VidCard to pop in there for the video memory dump test when it's thoroughly dried out would you?

I'm thinking my black Mac will be the souped up SE/30, gotta hide where the front bezel makes its pass across the router table. :rambo:

 

[LazarusNine]

Okay, so the board is completely clean (I went to some extremes) and I managed to replace half the caps (more on order). No improvement yet.

I don't have a PCI video card, unfortunately. That would be pretty fantastic if so. The screen is just too far gone to be able to see a floppy on the desktop or any icons from a screenshot. It's a really good thought, though.

I guess the next update will be once all the caps have been swapped out. If it's a VRAM issue, I'll be a little more helpless with that one. It might be hard to find a VRAM module to replace it with - let alone attempt to solder it on (my SMD soldering skills are intermediate at best)!

Here's a question. In a worst case scenario, if I have to swap out the logic board, is the 6400 board interchangeable with the 5400 board? Cheers!

 

[Compgeke]

Yes. A TAM or 6500 board would also fit if you had one of those.

 

[beachycove]

Aren't you missing a doohickey at R160 near the comm slot, btw?

 

[LazarusNine]

Aren't you missing a doohickey at R160 near the comm slot, btw?

I thought the same and then saw another 5400 board with it missing as well, so perhaps it's only there on certain configurations, etc.

Yes. A TAM or 6500 board would also fit if you had one of those.

Thanks. That's really good to know. Broadens my search options quite a lot actually.

 

[Trash80toHP_Mini]

A baseline, first gen PCI Mac compatible VidCard and one for NuBus (anything a little better than the TOBY Card) should be in every collector's basic kit. While you're at it, get the low end AGP card for the G4s that everyone loves to complain about. They work fine for anything basic and lowest common denominator it almost always best for degubbing.

 

[bibilit]

I should have a spare Logic board if you need one.