CD32 reset boot up fault

[trolleymaster]

Hi all

I have recently recapped my cd32 (about 2 months ago), and all was working fine until a few days ago when it started doing a strange boot-up reset loop.
I have posted a youtube video with the issue at the link below :

[ Show youtube player ]

It plays/boots games absolutely fine - with the exception of CD200 compilation - which no longer loads fully, it just stops at the "CD200" logo in the corner of the screen. Not sure if this is related.

A full recap has been done (by me), and Im confident it has been done properly - indeed it was working fine since I did it in January.
Im happy and competent enough with attempting any self repairs. Any help or suggestions would be gratefully received as Im not sure where to start.

Thanks in advance !

[th4t1guy]

Is it only that compilation that causes that behavior?

Are you using the original power brick?
Mice/Joypad plugged in or no difference?

[trolleymaster]

Hi
thanks for the assistance
its a replacement/3rd party power brick.
I dont have an original one, but I do have a spare A500 one that I could modify to try if you think that might be it ?

joypad plugged in or not makes no difference

also, I just tried the "Bitmap brothers compilation" and that does the same thing.

[th4t1guy]

It wouldn't hurt to check the power supply.
Have you opened the machine up and checked the caps you replaced? Maybe its possible that one was a dud?

[trolleymaster]

I'll get the power supply checked.
I did think that one of the caps may be iffy. I have opened up and checked them all - double checked polarity carefully, and checked the two electrolytics (that are screen printed incorrectly) are correct.
They all look ok, but I suppose it would be worth a recap again if the psu does not help ?

[Amiga1992]

Always worth a recap on these things. But your problem is rather weird indeed.

[th4t1guy]

I haven't used either one of those compilation cds, but are you confident that those exact discs worked before the recap (and I assume they worked immediately after if I'm reading your original post correctly)?

I would hesitate to replace all those caps if there's no evidence they are an issue, mainly because of all the work involved. One of the resident hardware gurus here would be able to give better advice on this board, but I would initially suspect maybe a cold solder joint or something shorting the machine when it's in the case if the PSU checks out.

[trolleymaster]

Thanks to all for your help so far.
the compilations worked fine straight after the initial recap.

and even in its current boot issue state, all "normal" games run fine - originals and backups

one other thing that may give a clue is that when the game is accepted by the cd32, the spinning "CD" logo has a checkerboard pattern on the "C". i've tried to capture it as best I can on the attached images. This was not present after the initial recap, but has appeared with this new fault.

I'll try the psu and report back.

[th4t1guy]

Very strange....other games running fine make me suspect it's not a hardware issue.

Maybe there's something in the NV ram those compilations don't like (or NV ram is full)?

[trolleymaster]

hmm, that sounds like a possibility
however, because the intro animation doesn't finish I cant access the nvram/clear memory options - pressing the button on boot doesnt work as it resets before I can get to it.

[Amiga1992]

Looks like RAM corruption.
Change the PSU, then if nothing changes, do check the recap, I am afraid that's your first step.

Also make sure nothing is shorting any pins of the expansion slot.

[wmsteele]

Might be nothing to do with your issue but have you checked the CD32s other caps, these often get overlooked... http://eab.abime.net/showpost.php?p=...4&postcount=57

[trolleymaster]

never looked at those !
I'll check those out too.

thanks everyone, I really appreciate you all giving your free time to help.

I'll report back and hopefully it will be helpful to the rest of the community.

[Amiga1992]

Oh yeah the CD assembly caps, wmsteele always points us out to this oft forgotten set of capacitors.

Let us know how you get on!

[xArtx]

Changing the 3 or 4 electrolytic caps along the same row as the alignment pots will also change the alignment of the CD drive. The caps are within a few percent tolerance or so of the value actually printed on them.

[xArtx]

NVRAM area can be accessed without any CD ever being in the drive from the menu, but no program you are booting can access it before it’s running anyway, and no program I’ve seen can clear the fanfare animation while it’s running. A CD already inserted and detected can prevent the fanfare playing, or clear the residual bitmap after it has played.

[xArtx]

cdstrap makes a copy of NVRAM to RAM to check a reserved area for settings such as Language, and perhaps audio CD player settings,
but that can be erased/reset in the language selection screen and game save editor without the need for a CD in the drive if it happens to be corrupt,
and it doesn’t explain most CDs booting ok.

Does it look like the CD has spun up properly before the fanfare animation starts?
That shouldn’t happen if it has already found an audio, CD32, or CDTV disc.

[trolleymaster]

Hi everyone

So I changed the power supply for a known good A500 one, and the same issue occurs so I would say that the PSU is ruled out.

I checked the caps on the cd assembly and to be honest they all look in pristine condition - difficult to say for sure I know, but to save any cd alignment issues I think I will hold off changing those for the time being.

If you put a cd in the drive before switching on, then switch on it boots striaght into the game before any fanfare/reboot issue.
However, I tried an audio CD and it doesnt get to the audio player screen - it just continually resets, but there is no fanfare screen.

Could it be corrupted RAM ?
Is this fixable ?

[supaduper]

If you can get a burned CD to work then try Akira`s Systest CD, here you can test the ram.
the link to the iso file is here
http://eab.abime.net/showthread.php?...93#post1187693

[xArtx]

Or ROM, is it a mask ROM, or burned EPROM?