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IBM ps2 P70 portable repair thread

Wait a second. These are through hole not smd? Ill investigate the caps (once i figure out where this area your referring to is) but if they are not leaky they will remain on the board. I dont just change out good caps willy nilly. Thats not good practice.
 
VERAULT said:
Can someone tell me if this unit supports Bi-directiona LPT as I cannot get my SD2LPT device to work on it. IS there something I have to set like a jumper? I cannot find anything in the system reference disk.
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You need to set the lpt to 2 using a ref disk then use the sddrv.sys from the nc100sd folder I just copy it to the root of the c drive on mine.

Hope that helps

Mike
 
My McIDE-CF arrived today and it works great!
Configured on the first try and no conflicts with the MCMASTER AOX. I bet a lot of P-70s ended up parted out or in a landfill due to dead ESDI drives, so it's nice to finally have a solution (plus tons of extra storage space).

Now I need a slot for one of the new MCA sound cards being produced by texelec. Does anyone have a good photo of the MCA riser in a P-75? It supposedly has 4 slots and I'm wondering if it might be a hackable project.
 
Torch said:
My McIDE-CF arrived today and it works great!
Configured on the first try and no conflicts with the MCMASTER AOX. I bet a lot of P-70s ended up parted out or in a landfill due to dead ESDI drives, so it's nice to finally have a solution (plus tons of extra storage space).

Now I need a slot for one of the new MCA sound cards being produced by texelec. Does anyone have a good photo of the MCA riser in a P-75? It supposedly has 4 slots and I'm wondering if it might be a hackable project.
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Glad to hear, and thanks for leaving feedback on the site!
 
I think this will be the final update on my P70 project.

I opened the case back up to examine the video board caps. They look pristine. And The only reason I would replace them at this point is to help with the ghosting that can be seen in some of the photos I posted when the machine is booted to windows. And Ill be honest. Im not at all convinced recapping the video board will help with this so unless it gets worse I think Ill put that off until its needed.
IMG_20240324_123050.jpgIMG_20240324_123100.jpg

The Texelec OPL3 Resound 2 board came in so I popped it in and coppied the file from the website to the reference disk.

IMG_20240324_123753.jpg
By the way looking at this photo.... Where the heck is slot 3?!?


Since this sound card is basically an adlib clone there was no software to install (i forget do you need to install adlib drivers in windows 3.11????)

I tested out a few games like Doom, The secret of monkey island, Planet X3 and Warcraft 1 and 2.. They all sound perfect for Music and no sound effects.

I think I made the best choice on a sound card for this machine. ITs barely a 486 and Im limited to 8mb of RAM so the types of games it can play is pretty limited (in fact some of the games I used for sound testing are to slow to actually play but they were good for sound testing) so paying 2 and a half times as much for a sound blaster compatible card just isnt worth it in my opinion.

I think I hit the ceiling with this IBM p70 as far as options go. Both slots are taken up, the RAM is maxed out, it has a hard drive card now, and a Cyrix 486 cpu upgrade. Unless someone makes something new I can somehow install in the midst of all of this; This machine is complete. And honestly I dont think there are a ton of these working out there so its too niche for specific upgrades.

Anyway I hope this thread gives people with the P70 (and a most likely dead ESDI drive) motivation to dust them off and get them up and running.

Mick

P.S. Special Thanks to @markgm for selling the McIDE-CF. If I hadn't spotted that card this computer would just be sitting on a shelf forever.
 
By the way looking at this photo.... Where the heck is slot 3?!?
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The original ESDI HDD has the controller card built in. Slot 3 is where the drive's ribbon cable plugs into on the motherboard...it's just a dumbed down MCA port. From what I've read, it doesn't have enough lines to hack it into a usable MCA port.

From some more searching, I guess the 4 slot P75 riser will physically fit in a P70 but won't work as it has some auxiliary board on it.

I wonder if MCA ports can simply be daisy chained like the I/O port of my Model III or the ISA adapters on my 1000EX?
If so, I can simply buy a female MCA connector and parallel it off the back of the riser by soldering on a short section of ribbon cable, then mount the sound card wherever.
I'm leaning more towards no as BIOS recognizes ports with nothing plugged into them.
 
Torch said:
The original ESDI HDD has the controller card built in. Slot 3 is where the drive's ribbon cable plugs into on the motherboard...it's just a dumbed down MCA port. From what I've read, it doesn't have enough lines to hack it into a usable MCA port.
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I dont know enough about MCA slots but has noone attempted to get the missing lines from elsewhere on the board?

I know when I still had PS2 systems; before I decided I would not collect them and got rid of them, I had one system with an mca card which had I think 8 ram sockets... Shame noone is making a reproduction of that.. And that slot 3 would be perfect as im sure a modern ram card could be made very small.
 
I'm no longer using the ESDI, so I unplugged the cables. After running the reference disk, slot 3 still shows up as empty...if that slot is empty, how does the system even know that slot exists?

I also ran the reference disk on my other P70 (still using the ESDI) and it does show slot 3 as Integrated Fixed Disk and Controller.
Slot 1 is MCMaster
Slot 2 empty

So I just examined the riser board and didn't see a single component on it; it appears to be pass-through. I'm confused as to how the system identifies the slots.

Plenty of P70 information here:

Of course they skip the Microchannel and refer you to the Hardware Interface Technical Reference Manual.
That's reading for a rainy day.
 
VERAULT said:
Im not seeing any pad issues. Are these old photos before you attempted repair. I do see trace damage from leaky caps but all the caps are still in place.

Anyway. If you got a new floppy and have no use for it. Would you sell it for the cost of shipping? If I can fix it it would be a good backup for my system since I only own one ps/2 system.
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I’m not sure I got much further than what’s in the pics. Maybe it was the trace damage I was thinking of or i did take off the cap and thought the pads were damaged. I may take a crack at it again some time so want to hold on to the drive. Please share the cap info for what specific caps you bought if you have it handy.
 
agentb said:
I’m not sure I got much further than what’s in the pics. Maybe it was the trace damage I was thinking of or i did take off the cap and thought the pads were damaged. I may take a crack at it again some time so want to hold on to the drive. Please share the cap info for what specific caps you bought if you have it handy.
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I keep thousands of caps on hand. I dont buy them per job (that seems crazy expensive and inefficient) .. So I dont keep track of these things.
 
VERAULT said:
I keep thousands of caps on hand. I dont buy them per job (that seems crazy expensive and inefficient) .. So I dont keep track of these things.
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Fair enough! I don’t do much repair work so buy caps as I need them.
 
VERAULT said:
Seems im not getting all the colors/shades as evident by the windows logo. IS there a specific driver for the p70? Im just really not familiar with this model. If anyone knows it well please share the info.
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Hi there. Not a driver per se but something you can try that worked for me on two of my machines. Make sure you have a good battery and you've completed all your initial setup/configuration via the reference disk (like setting date/time, hardware detection/configuration completed and saved etc.). If everything's configured, boot into DOS and switch the system to 80 column color mode (MODE CO80). The video card should then be set to color mode. Reboot into the reference disk, rerun the hardware detection then save. Reboot and see if that made any difference on the Win 3.11 splash screen.

If that doesn't work, boot into DOS, set 80 column color mode again, then access the configuration tool on the refdisk straight from DOS rather than booting into it, and rerun detection/save again. It's finicky and I haven't quite figured out why it sometimes works and other times not, but once it's actually set it should keep the setting permanently. Again, that worked for two of my machines. Also, I tend to switch to 80 column color mode on boot via autoexec.bat since some DOS applications look wonky if not doing so (also certain games will not load for some reason or another if I don't so kind of made that a habit for my P70s).

In addition, throwing in my two cents regarding caps on the P70. Recapping the floppy drive is a given at this point and seems to have a reasonable success rate (at least for me). I know there's a lot of back and forth on whether or not the system board should also be recapped as well. While it's true that the board doesn't really use surface mount caps and the through hole ones do not appear to leak and look cosmetically fine, I do feel that certain caps at least should be replaced. One of my machines was incredibly unstable e.g. would randomly freeze, would just stop during memory count, or just randomly refuse to boot outright. Once I recapped the motherboard I no longer had these issues and it's been rock solid since. Some of the caps I pulled were quite out of spec from an ESR rating perspective. Considering how compact (crammed really) these units are, and between rather cozy temps while running and probably years of use, swapping caps least near the critical components (power rails, RAM slots, etc.) might be beneficial. Also recapped the video card for good measure for the same reason.
 
I opened the case back up to examine the video board caps.
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You're looking at the wrong caps. You have to completely remove the video card from the system (which means removing the ISA cards and riser) to see the most dangerous through-hole caps. There aren't very many but if you look at my earlier pics, you'll see one right in the centre of the board, nowhere near the RAM in your photo that leaks.
 
The P70 Doesnt have ISA cards and I dont know who you are quoting. But again, if your talking about my own video board. Its working fine. If the caps go bad eventually. Then ill replace them eventually. I already examined them and my video is fine.
 
solidpro said:
Cool. Why bother to diffuse a time bomb that hasn't gone off?
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Thats the thinking that just implies "REPLACE ALL CAPACITORS". And I dont follow that logic. My machine works, and works quite well. So have no reason to replace them. I inspected the whole system when I was working on it and the capacitors look fine and behave fine...

Your heart is a literal ticking time bomb... You should replace it.. as one day.. POOF...

See what I mean?




I mean if it dies soon. Ill let you know and say you were right. Until then.. I have no real reason to touch those caps.
 
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