X68000 ACE HD problem

[nassekova]

So I got broken ACE HD which I recapped and repaired one broken battery acid trace. It had original PSU but some one in Japan had reworked it so it worked. I left it on stand-by for a week and then tried to start it, but it just showed the red light, until it didn't even show that.

I then took the PSU apart and it smelled really bad for capacitor fluid and was completely dead. Now I got the PICO PSU with mattsoft PCB and it seems to works fine. I measured all the outputs and when I connect it to my X68000 it starts the computer, OSSC get sync, but all I get is black screen...

Disks seem to work (lights goes red/green, eject works) but it does not start to load them (or at least I can't hear any motor running).

I also took the battery of to reset it and but it then back but the problems stays: It starts like everything is OK, red light turns to green and fann goes on on the PSU, OSSC gets SYNC but picture is just black...

Any ideas? I bet the old broken PSU broke something but I have no idea where to start troubleshooting... 

EDIT: Interrupt works and I get some japanese text displayed but holding CLR does not give anything.

[watto]

Do you have any pictures of the bottom board?  It'd be surprising if the battery leaking only damaged one trace.

That said if it's an ACE HD you may need to terminate the SASI if you don't have a HDD connected.  That would also be a common cause for a black screen on power up.

[nassekova]

If I disconnect the first floppy drive I get it to boot (I leave the 2nd floppy connected). But when I try to boot from the 2nd floppy it says "It was not possible to start the system. Reboot"

I neutralized the bottom board with vinegar and fixed it good and it worked before the PSU gave up, so I don't think it's that. And now I can get it to boot and show me that "insert disk" if I leave the first floppy disconnected. It just won't boot from the 2nd floppy :/ (that too used to work before PSU crashed)

[nassekova]

It also finds my SD2SCI when I leave the first floppy drive disconnected but it will give that same error "It was not possible to start the system. Reboot"

[watto]

There can still be damage to traces that are now exposed to air, damage to traces running under things, etc.  This can eventually cause issues.

When you say disconnect the first floppy, are you disconnecting the power?  How is the PicoPSU connected to everything?  You may need to run the floppy drives off the additional connector on the PicoPSU - they usually come with another connector with a Molex and SATA plug on them, you may need to power the drives off of that.

From the mattsoft page:

(5) When connecting your original X68000 harness to the PCB, @leonkiriliuk has suggested that the PicoPSU's ATX molex may not provide enough amperage for the floppy disk drives (FDD). It is advisable to wire the FDD leads from the X68000 harness to the 4-pin molex attached to the PicoPSU or your FDD may not work. v3 of this board will fix this by routing the 4-pin molex to a dedicated terminal on the PCB.

[nassekova]

Here is the picture of repaired bottom board (last picture is the fixed one)
https://www.instagram.com/p/CR8Ku0eDO-Y/

I have connected floppies from the harness, not from the molex ATX.

When you say disconnect the first floppy, are you disconnecting the power?

Yes, just took the 1st floppy drive power cable off and now it boots, but won't start the system.

[Jehuty]

I had a similiar problem with my XVI. On my X68000 it was some bad connectors from floppy cable. Data and power. After cleaning all it boots fine.

[nassekova]

I had a similiar problem with my XVI. On my X68000 it was some bad connectors from floppy cable. Data and power. After cleaning all it boots fine.

I think I need to double check my floppy cable but I think that there is a high change that old PSU broke another of my floppydrives. Going to try swap places of those 2 drives and if it is always the same one with the problem then I need to get a new floppy drive from somewhere...

Both of the drives worked perfectly before the old PSU went haywire so either it's the PICO PSU cable or then it's just broken drive.

[watto]

The drives themselves have a few capacitors in them that can go bad.  I'm not sure if your system has been recapped at all, been a while since I've had one open since the prices have gone up too much and I've stopped buying them   In any case if it hasn't been done it's worth doing.

Unfortunately it's pretty hard to speculate what the issue is from here, I could be more help if I had it on my bench.

The main thing I will say is check all the basics first - I've had issues with the power connectors for drives and the main one that connects to the bottom board to.  I know it's probably annoying to read that but it has caught me out loads of times and resulted in me wasting time checking things that were not the cause of the problem.  On my XVI I spent weeks faffing about with things only to discover the bottom board connector was basically falling apart and not making good contact on some pins, causing all the issues I was having.  The drive connectors are quite short between the two drives, and the pressure of having both connected could be making a bad connection if you've got some dirty pins.

[hoshikawa]

you need to check the VIA's under the battery on the bottom board, nearly always there is one or two open traces that cause the problems you are seeing.

[hoshikawa]

https://postimg.cc/RNR9btCJ

[nassekova]

I checked all of those VIA's when I fixed that battery damage, and like I said it worked fine before the PSU broke, so it would be a hell of a coincidence that it would break at the same time.

My problem is exact same as here: https://nfggames.com/forum2/index.php?topic=5703.0

[nassekova]

The drives themselves have a few capacitors in them that can go bad.  I'm not sure if your system has been recapped at all, been a while since I've had one open since the prices have gone up too much and I've stopped buying them   In any case if it hasn't been done it's worth doing.

Unfortunately it's pretty hard to speculate what the issue is from here, I could be more help if I had it on my bench.

The main thing I will say is check all the basics first - I've had issues with the power connectors for drives and the main one that connects to the bottom board to.  I know it's probably annoying to read that but it has caught me out loads of times and resulted in me wasting time checking things that were not the cause of the problem.  On my XVI I spent weeks faffing about with things only to discover the bottom board connector was basically falling apart and not making good contact on some pins, causing all the issues I was having.  The drive connectors are quite short between the two drives, and the pressure of having both connected could be making a bad connection if you've got some dirty pins.

Yeah, I will unplug it all and connect everything from the scratch this weekend when I start to troubleshoot the problem and I have some more time. Luckily I got it to boot with that one floppy disconnected so it at least gives me a hint for where to look first.

I recapped everything else except insides of those floppy drives, since it would have meant that I need to dissamble that drive and re-calibrate it again (which I heard is a pain in the ass). But if I can pinpoint the problem to that one floppy drive I will open it and give it full re-cap. It might be that the PSU gave it over voltage on +12 rail before died and burned something on there. 

[watto]

You shouldn't need to recalibrate the drives unless you accidentally move something mechanical.  eg. Don't unscrew the track zero adjustment screw.  There are also ribbon connectors within the drives that can do with being cleaned and reseated.

There are two caps near the power connector that are probably easiest to switch over without doing a full disassembly.

Useful info here: https://gamesx.com/wiki/doku.php?id=x68000:advanced_floppy_driver_repair

[nassekova]

The main thing I will say is check all the basics first - I've had issues with the power connectors for drives and the main one that connects to the bottom board to.  I know it's probably annoying to read that but it has caught me out loads of times and resulted in me wasting time checking things that were not the cause of the problem.  On my XVI I spent weeks faffing about with things only to discover the bottom board connector was basically falling apart and not making good contact on some pins, causing all the issues I was having.  The drive connectors are quite short between the two drives, and the pressure of having both connected could be making a bad connection if you've got some dirty pins.

Today I opened imperial stout and was prepared for the worst! I first disconnected both of the floppys, cleaned contacts on those, took everything apart and then tried each floppy one by one. First I could not get it to boot with floppy number 1, but after I cleaned the contacts suddenly I got it to boot with that too. After that I connected my SD2SCSI and now it works!

I tested both floppy drives and they work, I can boot with them or with SD2SCSI, so it actually was just some dirty connection on floppy side.

Only thing that does not work is booting from standby with PICO PSU. I need to switch the power off completely, then push the start button from the frontpanel, and then switch it on from the back and that works every time. Shutdown works from the front but when I try to start it up again, it will just stay on red. Well that's really no issue since it boots every time when I flip the switch from the back so I can live with that.

Thanks for the help everyone!

[watto]

Good to hear it's working again.

Soft power troubles are not that unusual, can sometimes be a failed transistor, but if it was working before I'd check the inverter chip you've used on your PicoPSU adapter board.

[Jehuty]

Are the 5VSB ok ?  Could try to replace the 74LS in the Poweron circuit. I could bring back 2 X68000 by replacing that.

[nassekova]

I think I have a bunch of those chips (74LS) and it worked in the beginning, but then at some point stopped booting back. Perhaps I switched it on/off too frequently when testing those floppies. When I next time open that thing I try to replace that chip, luckily it was socketed, so just needs to open the PSU.

[Jehuty]

I mean the 74LS08 on the subboard in the power on circuit, not in the PSU