abrunetto wrote on 2023-09-12, 21:38:

Hi Folks! I am trying to restore to a working condition an IBM PS/2 model 80 with a planar type 3 (yes, japan designed). Everyt […]
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Hi Folks! I am trying to restore to a working condition an IBM PS/2 model 80 with a planar type 3 (yes, japan designed).
Everything seems to be in good shape, but unfortunately I am facing a (very) tricky issue, the ones that I love.
So, I am able to POST the machine just when it is cold, and one out of 3 to 5 tries. When it POSTs, the SCSI HDD boots with a shiny MS-DOS 6.00 (just command.com and the hidden files), and the machine hangs about 30 seconds after.

Then, if I power cycle, I only get the (in)famous black screen (no beep, no POST messages, no blinking cursor, no orange LED, no nothing), just BLACK screen.
Sometimes. if I removed the RAM module (4MB) I get 211 memory error, which seems to be fine. If a install the memory on the second memory bank I get 215 error code, which also seems to be fine.

Sometime, when it POSTs the memory counts 3712 with 201 and 164 error. The right amount of memory is 3968, with no errors at all.

PC Speaker is working fine, as well as the 3v battery.

The 5V, 12V and -12V power rails seems to be estable, but the power good signal is around 3.73V.

I don't know if 3.73V is within power good tolerance (should be 5v).

I power on the psu alone, wait several minutes and then plug it in on the motherboard, and power on again. If the motherboard was cold, it has the same behaviour as before, with a "cold" PSU.

Any help would be very appreciated.

Best Regards,
Ariel

Model 80 uses a 6V cmos battery in high current ability. I tried two CR2032 in series and couldn't supply surge current during start up. Had to be this battery,
Duracell Ever Ready Panasonic Kodak Varta Ray-O-Vac Sanyo
DL223A EL223AP CR-P2 K223LA VL223 PC223 CR-P2

Cheers,

Hi. Thank you for your reply. I didn't check the battery voltage. I assumed it was a 3V and I also assumed that the battery works since the machine keeps date and time.

If the battery is worned out, the system won't post?

Regards,
Ariel

[/quote]

Model 80 uses a 6V cmos battery in high current ability. I tried two CR2032 in series and couldn't supply surge current during start up. Had to be this battery,
Duracell Ever Ready Panasonic Kodak Varta Ray-O-Vac Sanyo
DL223A EL223AP CR-P2 K223LA VL223 PC223 CR-P2

Cheers,
[/quote]

Won't keep configuration.

Cheers,

Sure, but it should POST anyway right? Even without the battery.

Regards

pentiumspeed wrote on 2023-09-13, 00:10:

Won't keep configuration.

Cheers,

abrunetto wrote on 2023-09-13, 00:32:

Sure, but it should POST anyway right? Even without the battery.

Regards

They should post without battery, but they throw 161 and 163 errors and you need to boot the system with setup/reference disk to update the configuration. This is every time you power on the system, if you don’t have battery.

Many of these systems have extremely unreliable and not standardized floppy drives and if your battery runs out and your floppy drive doesn’t work, the system is mostly useful only as a decoration or paper weight. That is before repairs or adapter mods for standard drives, but you need a working floppy drive to keep these systems running.

You also need to use that reference disk when you modify the system, for example add memory. Have yoy tried to boot the system with reference disk and updating the configuration?

They should post without battery, but they throw 161 and 163 errors and you need to boot the system with setup/reference disk to update the configuration. This is every time you power on the system, if you don’t have battery.

Sure but most of the time it didn't POST, even without battery.

Many of these systems have extremely unreliable and not standardized floppy drives and if your battery runs out and your floppy drive doesn’t work, the system is mostly useful only as a decoration or paper weight. That is before repairs or adapter mods for standard drives, but you need a working floppy drive to keep these systems running.

Floppy seems to be working just fine. Anyway I have a model 50 with a working floppy

You also need to use that reference disk when you modify the system, for example add memory. Have yoy tried to boot the system with reference disk and updating the configuration?

Sure, I know that. But most of the time it didn't post at all, ending just with a black screen without beeps or errors.

Regards,
Ariel

Careful. Model 80 floppy drive is not same as model 50 which is only compatible with model 70.

Yes, there will be many weirdness due to dead cmos battery. Get new one first or use two CR2 3V lithium batteries in series for testing but make sure the battery's holder terminals on the computer is correct.

Cheers,

pentiumspeed wrote on 2023-09-13, 14:48:

Careful. Model 80 floppy drive is not same as model 50 which is only compatible with model 70.

Good info, thank you.

Yes, there will be many weirdness due to dead cmos battery. Get new one first or use two CR2 3V lithium batteries in series for testing but make sure the battery's holder terminals on the computer is correct.

Cheers,

So, it is still possible to get a black screen with a dead battery? I could manage to get a CRP2 battery locally. However I think the issue is around the planar, maybe some voltage regulator or cap (ir seems to has very few caps). What do you think?

Regards,
Ariel

abrunetto wrote on 2023-09-13, 19:10:

Good info, thank you. […]
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pentiumspeed wrote on 2023-09-13, 14:48:

Careful. Model 80 floppy drive is not same as model 50 which is only compatible with model 70.

Good info, thank you.

Yes, there will be many weirdness due to dead cmos battery. Get new one first or use two CR2 3V lithium batteries in series for testing but make sure the battery's holder terminals on the computer is correct.

Cheers,

So, it is still possible to get a black screen with a dead battery? I could manage to get a CRP2 battery locally. However I think the issue is around the planar, maybe some voltage regulator or cap (ir seems to has very few caps). What do you think?

Regards,
Ariel

Depends. The model 80 is one I don't know. I know 50, 70 and 90 XP because I had them, and did work on 25 and 30 back in the day.

Cheers,

from the BIBLE: http://ps-2.kev009.com/pcpartnerinfo/ctstips/49fe.htm

210 (PS/2) Parity error in base 64K

215 (PS/2) Base 64k on daughter card 2 card failed
On a PS/2 Mod 80 if you remove the memory card from a configured system and
plug it into the 'other' slot (either by mistake or deliberately), you will
get a 215/216 error during POST. You will not be able to run SETUP.
Fix the problem by moving the card back to the other slot.
If you really want to change the position, you will either have to disconnect
the battery (for a long time) or configure the machine with TWO memory cards
and then remove the one that you don't want and reconfigure it with one
again.

luckybob wrote on 2023-09-14, 00:11:

from the BIBLE: http://ps-2.kev009.com/pcpartnerinfo/ctstips/49fe.htm […]
Show full quote

from the BIBLE: http://ps-2.kev009.com/pcpartnerinfo/ctstips/49fe.htm

210 (PS/2) Parity error in base 64K

215 (PS/2) Base 64k on daughter card 2 card failed
On a PS/2 Mod 80 if you remove the memory card from a configured system and
plug it into the 'other' slot (either by mistake or deliberately), you will
get a 215/216 error during POST. You will not be able to run SETUP.
Fix the problem by moving the card back to the other slot.
If you really want to change the position, you will either have to disconnect
the battery (for a long time) or configure the machine with TWO memory cards
and then remove the one that you don't want and reconfigure it with one
again.

Sure, but that is only when it POSTs. Mine doesn't POST most of the time and when it POSTs, it loads the msdos on the SCSI HDD, and hangs after 30 to 60 seconds.

I think the issue is in the planar or in the power good which has 3.73V instead of 5v.

Tomorrow I will measure the cmos battery voltage.

Regards

Yea, that just screams memory errors. You have a bad connection somewhere. Those memory boards are made out of suck and fail.

I'd do a deep cleaning, and make sure there is no corrosion anywhere. Check anything in a socket, the L2 cache as well.

Yea, that just screams memory errors. You have a bad connection somewhere. Those memory boards are made out of suck and fail.

I'd do a deep cleaning, and make sure there is no corrosion anywhere. Check anything in a socket, the L2 cache as well.

I already cleaned everything. But, what about the fact that the machine only POST when it is cold?

Regards,
Ariel

abrunetto wrote on 2023-09-14, 07:29:

I already cleaned everything. But, what about the fact that the machine only POST when it is cold?

Regards,
Ariel

Thermal expansion or specs of some failing component change for worse when it gets warm and system doesn't work anymore.

If cleaning didn't help, I'd also check the planar closely for cracked solder joints, especially for memory slots.

pentiumspeed wrote on 2023-09-13, 14:48:

Careful. Model 80 floppy drive is not same as model 50 which is only compatible with model 70.

Yes, there will be many weirdness due to dead cmos battery. Get new one first or use two CR2 3V lithium batteries in series for testing but make sure the battery's holder terminals on the computer is correct.

Cheers,

I measured the battery and it has a steady 4.37V which is far below 6V. I removed the battery, and I was able to use the machine for 10 minutes before it hangs. Before I was able to use the machine just 1 o 2 minutes. Recycle the power when it is hot, get me back to the black screen (no beeps, post, nothing). I have to wait 20 o 30 minutes at least before power on again, in order to POST. I am waiting right now.

Regards,
Ariel

There has to be a loose solder joint somewhere.

luckybob wrote on 2023-09-14, 19:59:

There has to be a loose solder joint somewhere.

Any clues how to find it?

Regards,
Ariel

Should I clean memory board connector contacts? It is ok to use isoprophyl alcohol or there is a better option?

Regards,
Ariel

this is the GO-TO stuff to buy: https://www.amazon.com/Hosa-D5S-6-DeoxIT-Cont … B00006LVEU?th=1

I dont know what is available in your area, but generic "electronics contact cleaner" should be what you are looking for.