Mac IIx Boot Issue- Boots in a loop or wont stay on

[CompactMacLover]

Alright guys, Got an issue here, Got a nice IIx, got it home fired it up. Boots to the happy mac, then reboots constantly, then after letting it sit for a second, it wont boot. Any ideas??

 

[Strimkind]

I think that means that the system has been unblessed. I would insert a boot floppy and check the system folder...see what is going on there.

 

[CompactMacLover]

Wont boot off a known good floppy either. It has power issues as well, hit the power button it goes off as soon as it comes on, hit the power key on the keyboard it stays on. Weird Machine Also doesnt have a boot chime.

 

[Unknown_K]

Check the motherboard for leaking capacitors, I had to recap my units.

 

[CompactMacLover]

No leaky caps. Oddly enough the II i got was missing floppy and hard drive and video card, but that boots fine once I installed those.

 

[Unknown_K]

Reseat the ROM SIMM.

 

[CompactMacLover]

I think im gonna shoot me a IIx and a II, both of them are doing the same thing. One tries to boot off the floppy then stops and spits it out. I dont know what else. Caps look great. Everything is clean, batteries got juice.

This is why i stick with compact macs they are simple this is turning out to be a chore

 

[Unknown_K]

Are you sure they is no wet looking dust around the aluminum capacitors? Did you remove and reseat the ROM SIMM (next to the RAM under the drive tray)?

Are you using 800K floppies (DD not HD) on the II (it didnt have a superdrive)?

What voltage are the batteries at (you need over 3V on a 3.6V battery or they don't boot reliably or at all)?

 

[CompactMacLover]

Yup yup both reading 3.4v. ROM reseated. Im making a set of SSW 6.0.8 800k right now to boot on them. I got the II to boot off SSW 6 with no problem. These machines arent dusty at all, it looks like they were in use right up till I got them

 

[Unknown_K]

From my experience with the IIx machines I own (2 complete units and a spare motherboard) is that the capacitors do tend to leak and the ROM SIMM sometimes doesn't have a good contact in its holder because of oxidation (you can apply slight pressure to the side and the machine bongs). In my case I just recapped all 3 boards and cleaned the edge connector of the ROM SIMM and all work great (with new batteries).

Kind of reminds me of a LC III I had that booted up fine and worked when I got it (for about 10 minutes when there was a noise coming from the speaker) and the machine never booted again. This was from capacitors finally going bad when I turned it on, recapping that board made it work like new. You can tell when the speaker bong volume is very faint the caps are about dead, same in compacts like the SE/30.

 

[CompactMacLover]

Thanks for all the help. Looks like Ill be keeping the II, mainly because it goes along with my Mac SE from 87

 

[Unknown_K]

Giving up on the IIx then? They are kind of rare you know.

 

[CompactMacLover]

How rare, ive heard of them but never seen one until I got this one

 

[Unknown_K]

Rarest of the II, IIx, IIfx line. The Mac II was out a long time before the IIx came out and then in under a year the IIfx came out and nobody wanted a IIx.

 

[CompactMacLover]

Thanks for all the help. After fussing around with it more and more. I finally got it up and running, I mustve reseated the rom twice, cleaned all the contacts. reseated the ram, and batteries. Its now sitting running with SSW 6.0.8. No sound though for some reason. But its up and running. Someone put a 1GB Hard drive in the darn thing. So if I can round up a stock 80MB Drive ill put one in it. As far as my II is concerned, Ill snag a floppy drive out of my SE parts stash and install it, same with a hard drive and thatll be up and running.

Once again thanks for all the help

 

[patatas]

Nice thread.

I have had the same identical issue with my IIx and have fought on & off with it for a couple of years.

Now I have a new reason to pull it out of storage and try reseating ROM !

Question: I know recapping capacitors mean replacing them but can someone indicate how many (exactly and which?)

 

[Unknown_K]

I just looked at mine and noted 15 pcs of 47uf 16V aluminum eletrolytic capacitors. There might be a couple of the non metal can variety but they seem to last forever and don't leak so I leave them alone. Basically an easy job and only 1 type to buy.

 

[patatas]

One blatantly stupid question; when we talk of re-capping capacitors we are talking about motherboard and not power supply?

 

[Unknown_K]

Yes just motherboard.