A1000 - dies after loading kickstart???

[Steady]

I am trying to get an A1000 going again but coming up against something that has me stumped. Not being a hardware guru by any stretch of the imagination, I need a bit/lot of help to work it out.

I have created some new kickstart disks on my A1200 since the original Kickstart 1.1 disk is dead (yep, it had 1.1). I created two copies each of a Kickstart 1.3 disk as well as a Kickstart 1.2 disk to reduce the chance of disk errors being an issue.

I turn on the computer and it goes through the usual sequence before presenting the "Insert Kickstart" disk. I put the disk in and it reads in the expected number of tracks (22 or 23, can't remember how many). Then the computer goes into the expected reset sequence of dark gray/light gray/white before the display cuts out and the computer in effect dies (no disk clicks if the disk is ejected, etc). It does respond to Ctrl-Amiga-Amiga to reboot and uses the loaded kickstart image rather than the ROM because it does the same thing.

This happens regardless of kickstart version or disk used. This is totally weird and appears to be a short of some kind that is caused when a certain part of the hardware is accessed. Any ideas???

[spirantho]

You really need to test your kickstart disks on a known good A1000 (or test a known good kickstart disk on your A1000). Not sure how you'll do that unless you happen to know someone nearby with an A1000 though! If you're in the UK I can try if you like.

[save2600]

I'd guess your Kickstart disks are no good. Bad dumps/transfer/disks. Are you using low density disks? If you're 100% positive you're properly creating Kickstart disks (they will say 'KICK' upon insertion while in Workbench), then maybe check the daughterboard inside the A1000 and the two chips to the right of it. They may all need to be reseated.

[rkauer]

Also the common Amiga troubleshooting is advised: check voltage rails for proper voltage levels, then pull (CAREFULLY!) and reseat all socketed chips and at a last resort start to replace electrolytic capacitors on the main board and PSU.

[Steady]

Thanks everyone for the replies. Actually, I'm in Melbourne so I won't be able to take up the testing offer unfortunately. Also, I know no-one with an A1000 here at this point.

Perhaps the A1200 I make the disks with has slight alignment problems, but I do know what a kickstart is meant to look like and when looking on the 1200 it seems fine. Also, the A1000 at least recognises it and loads the tracks. That, of course, doesn't mean that the content couldn't still be wrong.

I will try reseating the chips as suggested... other people seem to experience mysterious fixes after trying that.

Cheers all. I will post whether or not it works.

[mingle]

Hi Steady,

I have an A1000 with exactly the same issue.

I actually got it to boot a couple of times, but no idea why it worked on those occasions!

I tried reseating and even swapping most or the socketted chips, with no change. I also tried new KS disks. I also tried a different floppy drive with no luck.

Let me know if you find a solution!

Cheers,

Mike.

[Steady]

Well, I have some news. I think I isolated the problem with the weird A1000 boot behaviour. I was testing it on a multisync monitor (which is an acorn-branded M1438) which syncs down to 15khz no worries. I had it for years hooked up to an A4000 so I could use the AGA pass-through to have whatever mode I want. Anyway, about 10 years ago the AGA output stopped working on the A4000 and then about a year later it wouldn't boot.

Long story a bit shorter, I'd given up on the A1000 and moved to trying to fix the 4000, finding that it seemed to hang around the end of the boot sequence (booting from 3.0 WB floppy and not much other hardware). It seemed suspiciously the same behaviour as the A1000, so I tried the A1000 on the TV and it booted and works fine!!!! Even the A4000 finishes booting through the TV although it seems the RGB output is fried (looks like I'll need another thread for that one).

So, it seems that the RGB-VGA cable I was using is defective! One step at a time, these Amigas are being revived :-D

[mingle]

@Steady,

You're spot-on!

Same thing with mine - I use an NEC Multisync II, which has been fine on all of my other Amiga systems, but for some reason, when it's connected during boot-up I can't get past the KS screen, just as you mentioned.

I'm not sure it's a faulty cable, as mine looks fine.

I can reconnect the monitor after KS has booted and everything else works fine...

Maybe it's something to do with grounding? My cable has all of the RGB ground connected together - maybe this is the problem?

Cheers,

Mike.

[mingle]

Just another update...

I've double-checked my AMIGA RGB - NEC Multisync cable and it's all correct.

I also tried using another older NEC Multisync monitor (the original/first one) and it works fine! (ie: Boots the Kickstart disk every time)

So there's something starnge about the Multisync II (and possibly other multisync monitors) that my A1000 doesn't like...

Cheers,

Mike.

[Steady]

Thanks for the extra info Mingle. Glad it helped you out too. It is a strange one though.

[CLS2086]

Beware, since kick1.2 it's PAL or NTSC related !

[Zac67]

Try without any monitor connected on bootup to see if that changes anything. Some monitors put too much load on the sync signals, causing Kickstart (after being loaded!) to activate genlock mode - there's no external sync, so Amy stalls.

If that does make any difference, you can put a resistor in line with the sync signals in your cable. I've got no idea what size, so I'd start with 1kOhm.

[mingle]

Hi,

It always boots fine with no monitor connected.

However, it also boots fine with a 1084 and an original NEC Multisync - but not the Multisync II...

So it sounds like the sync problem with that monitor, for some reason.

I might try that resistor when I get the chance.

Cheers,

Mike.