Mac IIsi a fire hazard??

[Unknown_K]

Very rare early production units I think.

 

[techknight]

I thought so... I remember seeing a few IIsi units in my time and i only ran into ONE that had a ROM SIMM. rest did not.

 

[LC_575]

It appears that my IIsi is really dead. I got my video converter in today - the IIsi gives no display when booting, so no sad mac after the chimes of death.

 

[Dennis Nedry]

Hmm

You're consistently getting the chimes of death now?

Death chimes don't always provide video. From my experience, <50% of real death chimes show anything on the screen. The Mac must still be fairly healthy if you do get the chimes, it requires a lot of good hardware to get that far. A severely damaged Mac will not chime at all. Also, your video adapter might not be configured right, or won't work with your particular monitor. Old Macs like the IIsi often lack standard sync signals.

Do you have the board installed with the blown capacitor? Make sure to try booting with that board removed. Also try cleaning the logic board. Most of my IIsi's came with major capacitor leakage.

 

[LC_575]

I do not have that card installed - of course I removed it. The motherboard appears to be pretty clean. I managed to get it to boot without death chimes, by removing all of the memory modules, and even read a boot floppy, but it halts after a point. Still no display - my adapter has multiple modes - would it be helpful if I posted a pic of it here?

 

[Dennis Nedry]

Sure, that would help, maybe one of us could find a clue and provide more suggestions. Also, if possible, try it with several different monitors. I have a graphite Studio Display and an LCD that will NOT work with IIci or IIsi, yet I have a couple of other Trinitrons that work perfectly or partially (green/washed out/etc). Some screens are more picky than others.

The way it sometimes works and sometimes doesn't screams "bad caps" to me. I'd at least run it in the dishwasher to remove any invisible leakage and conductive particles. Or replace the caps. A sloppy power supply could also cause the crashing and capacitor explosion you've witnessed.

 

[LC_575]

Here's the ebay page for the converter I bought, the one in the pics is identical to what I have:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260625981691&ssPageName=STRK:MEWNX:IT

Currently I'm using an IBM monitor, my only spare, although i've got a Dell CRT in the garage I could drag out. I'll try it on that and my LCD's as well. Heck, I could even try it on my TV :lol: big screen System 7!

 

[Gorgonops]

I used to have exactly that video converter... what setting are you using? I would try the "13 inch 640x480" setting, not any of the multimode ones. I don't think the IIsi supports any higher than 640x480 (see Here. The IIsi can use *at most* 320k of onboard RAM for video. ) and it *may* predate the Macs that supported "normal" VGA monitors.

Fair warnings, LCD monitors may not care for the "13 inch" mode, but most CRTs should at least pretend to work.

 

[LC_575]

@Gorgonops i'll try that out, I was using the multimode settings.

BTW, someone had upgraded the memory in my IIsi - it has 4 simm's, 2MB each. However I doubt they work anymore...

 

[LC_575]

Tried two Dell monitors and a LG LCD monitor, no luck. Is it possible that my converter is faulty?

 

[Dennis Nedry]

From what I see here, try setting the adapter with switches 1 and 2 on, the rest off.

 

[LC_575]

I tried every mode. None of them work, and I think the converter DOES work - when I plug in my Dell CRT into the connector itself, the color test screen disappears.

Could a dead PRAM battery be causing this? Or is my IIsi ready for harvesting?

 

[Bunsen]

I tried every mode.

All 64 of them? (2^ 8) With a restart in between? That would have taken a while.

First, change your PRAM battery. Second, try a similar aged Mac monitor, and/or follow Gorgonop's suggestions. use the oldest VGA monitor you can find.

 

[LC_575]

No, I tried every listed mode, :lol: . Honestly I'm running out of patience; tomorrow I'm getting a new IIsi, and I know that one works.

 

[Dennis Nedry]

Perfect! Swap parts between the two to narrow things down, then you can have TWO working IIsis! Or at least plenty of spare parts.

Sir Bunsen: I believe you meant 2^6, but indeed 64 possible combinations is spot-on.

 

[Bunsen]

I believe you meant 2^6

Indeed. i don't know why I typed 8 instead, as 6 was what I was working from.

 

[Gorgonops]

First, change your PRAM battery.

This thread is getting too long and unweildly, but... did you try that? I don't know if the IIsi is one of them, but a number of 68k Macs won't produce video unless they have a working PRAM battery. (LCs fall into that category.)

Googling around it does appear that the IIsi uses composite sync rather than vga-standard seperate horizontal and vertical sync. Some (many?) Multisync CRTs can accept composite sync on their hsync pin, but since I don't own any machines that old I can't comment on whether that might be a feature that's becoming extinct. If you were looking for a monitor just for this purpose that's not the original equipment I'd recommend a medium-to-high-end early-mid 90's vintage NEC or similar. Anything made after 2000 or so I wouldn't *bet* on unless it was really high end. (IE, was made to work with UNIX workstations or the like.) A composite-sync friendly monitor is all that will work with a "gutless" adapter like what you have. They used to sell adapters which contained active components to seperate the sync signals so you could use monitors which didn't support composite sync... you may have a challenge finding one. (Apple apparently sold an adapter *themselves* to allow the IIsi to work with newer Apple monitors. Stacking one of those with your switching adapter might work...)

Or your monitors and adapter may be adequate and the machine is simpy dead. RIP?

 

[CelGen]

You can put the adapter back in after you remove the blown tant. I know it's more risky running without the filtering but it should still be fine. The blast mark you saw on the main board was just residue from the tant when it was still smouldering. I had the same marks on a 5160 when it started blowing up tants all over the ISA bus but it still worked fine.

I owned a IIsi once and I do recall that the onboard video was very picky about monitor frequencies and resolutions so I just stuck with a mac display and got around all this multisync monitor BS.

 

[LC_575]

Actually, I decided to give up xx( . The IIsi has been harvested, and now it's logic board (presumably dead. Outside of no video, it would never load any boot disks or boot w/o death chime with memory installed) and case lay in the garbage.

 

[Dennis Nedry]

You should put it on the trading post, free + shipping. Someone may want parts or do a case mod, etc. It's a dandy little Mac.