XVI Compact doesn't fully shut down

Started by NFG, December 16, 2010, 09:34:46 AM

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NFG

So I had the chance to try out my carefully formatted and prepared 3.5" floppies on the XVI Compact last night, and to my great dismay it seems the system is a bit flaky, and I wonder if I'm doing something wrong.

For the purposes of testing I attached only the power cord, no video or keyboard or other peripherals.  When plugged in the 10/16MHz light comes on, and the fan spins up.  But, and this is weird, it does both these things no matter the position of the power switch.  On or off makes no difference.  When it's off the music fades out and stops as it should, but the lights never go out and the fan never stops.

Is it upset about the missing peripherals and connections?  Is this normal?  Or if it's weird and broken as I suspect, what's the cause? 

netwalka

#1
Quote from: Lawrence on December 16, 2010, 09:34:46 AM
So I had the chance to try out my carefully formatted and prepared 3.5" floppies on the XVI Compact last night, and to my great dismay it seems the system is a bit flaky, and I wonder if I'm doing something wrong.

For the purposes of testing I attached only the power cord, no video or keyboard or other peripherals.  When plugged in the 10/16MHz light comes on, and the fan spins up.  But, and this is weird, it does both these things no matter the position of the power switch.  On or off makes no difference.  When it's off the music fades out and stops as it should, but the lights never go out and the fan never stops.

Is it upset about the missing peripherals and connections?  Is this normal?  Or if it's weird and broken as I suspect, what's the cause?  



Definitely matter of capacitors on the mother board.

Exchange them with new one will clear the problem.



Without the renewal of capacitors, from now on, these kind of matter come to spread in no particular order

...like Bus error, PCM  sound doesn't come out,  suddenly FDD doesn't boot anymore, FDD's soft eject doesn't work well, SCSI HDD doesn't boot.. etc

If you make the monitor brighter, you may see your monitor displays the last screen even after you switch off the Compact model, not bright but vague and dark screen.

Symptoms are little bit different machine to machine, but the reason is condensers.

You should clean the leakage when you change the capacitor.

That's not seen clearly like battery leakage, but should be cleaned. When it's ironed, you can smell it.....:-D

That leaks will infiltrate into your mobo's printed pattern and corrode.


And there is one more thing.

The printed pattern rise up(...peel off) from the board easily, when you remove capacitors. `Cause it is old enough.

I'd advise extreme caution.

NFG

Well then!  It's a good thing the Compact is so much fun <cough> to take apart.  I guess I'll be putting some effort into this.  =)

NFG

#3
There are no faults visible with any of the dozen or so capacitors on the motherboard.  No bulging, no leakage.  There are a lot of additional SMD caps present, but they also look fine.

The power supply is similar - none of the caps show any sign of leakage or failure.

I'm inclined to believe the problem lies elsewhere...

EDIT: Spoke too soon.  I found a dozen of the smallest solid-state caps that show signs of corrosion nearby.  Check out the vias in these images:






NFG

#4
Here's a list of the XVI Compact capacitors, for my own benefit as well as anyone who ever needs to replace theirs too:

tantalum (Nippon Chemi-Con):

5 x 1uf 50v (1P)
7 x 4.7 25V (13 / 18)
15 x 100uf 6.3V (1J)
1 x 10uf 16V (M4)
5 x 47uf 6.3V (14)
1 x 22uf 6.3V (1a)
4 x R47uf 50V (1A (?))
1 x .47 50V (P4)

electrolytic (85°C):

5 x 470uf 6.3V  Nichicon VX(M) H9119
4 x 100uf 16V Nichicon N045 (one on the keyboard mini-PCB)

These are all listed, in order: quantity, uf, V, and any part numbers or additional markings.

caius


RobIvy64

Lawrence,

How is your compact running after the capacitor replacement?

I just ordered the capacitors in your above parts list for my compact, which is suffering from some unusual issues (PCM louder than FM, blank screen during gameplay, etc...).

Upon inspection of the motherboard, the caps are obviously leaking. This will be fun! :(
"Console Mods" lurker

eidis

 Don't forget to replace capacitors in PSU as well to avoid "Magic Smoke"

Eidis
X68000 personal computer is called, "X68K" or "no good good" is called, is the PC that are loved by many people today.

RobIvy64

"Console Mods" lurker

NFG

I haven't gotten around to it yet, it wasn't long after the first post that I was flooded and lost most of my X68000 stuff, as well as most of the interest in working on it while I moved house twice and tried to sort out other stuff, like a bed and a fridge.  =)

eidis

Please accept my deepest condolences.

Eidis
X68000 personal computer is called, "X68K" or "no good good" is called, is the PC that are loved by many people today.