IIsi won't power up

Have you removed the PRAM battery? Based on the video weirdness preceding the non power up issue, that would be my first area of attack. Chances are that the PRAM battery is dead. Usually they last 3-7 years, in the case of the IIsi I had in the old days (lives in a closet in my parents' house now) - the pram battery went and caused a no start issue.

Bring the old battery to your nearest Radio Shack or Apple Reseller, and you should be able to get one without issue. (Apple used the same PRAM battery from the II series all the way up to the last of the G5 towers and iMacs (the intel macs use a button cell CR2032/2025 type battery).

Be prepared to pay an arm and a leg at RadioShack. If there are any battery specialty stores in the area, or if you can order online, they can be had for $5-10. Last time I looked RS sold them for nearly $15.

Thanks for the fast reply, it is much appreciated. I knew the battery was not working properly as the machine would not keep the date/time after power off but I never considered that a bad battery would cause this kind of issue. I will replace it ASAP. And thanks again.

Thanks for the fast reply. RadioShack may be my only option for the battery as there are no specialty battery stores that I know of. I will have to do my homework on this one. Thx again.

Yes, still no powerup. I then left the unit plugged into a wall outlet for about 8 hours then tried again. Still no power. I tried substituting the original power supply and also made sure the power cord was good. Still nothing. ???

Today I removed the hard drive, diskette drive and Nubus adapter card, then tried power up again. Again, nothing. Even the fan does not spin. I removed all the memory and tried again; nothing. I then put one SIMM back in; nothing. I tried both the first and fourth memory slot for this one SIMM. I then put everything back together. I am thinking now, maybe I can rescue the data off of the HD if I can figure a way to get it to work. Maybe an external case? Thx in advance for any comments.

These machines need RAM in sets of 4. They have 1mb on board, so you can boot to a minimal system with no SIMMs in place, or at least power up self test and try to boot. That will simplify testing.

Hey,

As I remember my IIsi, it had only two slots. And they were 30-pin SIMMs at that so it was a very limited upgrade path. But yes, it had one on the board, so it should start without any added RAM.

William
www.williamahearn.com

Four slots in a IIsi. It is a genuine 32 bit computer, so 30 pin SIMMs need to be installed as a (relatively) matched set. It probably requires SIMMs with 8 or 9 RAM chips (according to non-parity and parity FPM), but should boot unreliably with later SIMMs with two or three chip modules. Two and three chip modules were available when the IIsi was nearing end of life, so it is possible that some boards accept them.

Thx everyone for the replies. After reading them I removed all the memory, tried to power up. Nothing. I then tried control/apple/poweron; still nothing. I turned in that "poweron after shutdown" screw"; still nothing. I put all the memory back in, again nothing happens when you hit the poweron key on the keyboard. I removed the monitor power cord and cable; no powerup. I've reconnected the monitor. Could the keyboard be bad? I did clean the poweron key, that was one of the very first things I tried. ?????

Hi, I'm coming in late to this...it looks like you replaced the PRAM battery...did you actually zap the PRAM?

Quoting from the Service Manual for the IIsi:

Symptom Charts
Video
Screen is dark, audio
and at least one drive
operate, fan is
running, and LED is
lit
1 Adjust brightness on monitor.
2 Verify monitor works with different Macintosh.
3 Replace monitor. Refer to appropriate monitor manual to
troubleshoot defective monitor.
4 Replace video cable.
5 Replace video card.
6 Replace SIMMs. See Hardware/Memory.
7 Replace logic board. Retain customer’s SIMMs.
8 Replace power supply.

Screen is dark, audio
and drive do not
operate, but fan is
running and LED is lit
1 Verify monitor works with different Macintosh.
2 Replace video cable.
3 Replace monitor. Refer to appropriate monitor manual to
troubleshoot defective monitor.
4 Remove NuBus cards.
5 Remove peripherals.
6 Replace SIMMs. See Hardware/Memory.
7 Replace logic board. Retain customer’s SIMMs.
8 Replace power supply.

Partial or whole
screen is bright and
audio is present, but
no video information
is visible
1 Verify monitor works with different Macintosh.
2 Replace monitor. Refer to appropriate monitor manual to
troubleshoot defective monitor.
3 Replace video cable.
4 Replace logic board. Retain customer’s SIMMs.

Screen is completely
dark, fan is not
running, and LED is
not lit
1 Plug the monitor directly into a wall socket and verify that
the monitor has power.
2 Remove NuBus card and switch on power again. (NuBus card
draws more than 45 watts.)
3 Remove peripherals.
4 Replace power supply.
5 Replace logic board. Retain customer’s SIMMs.

From the original post, I think you said the fan wasn't running...this sounds like one of the more serious options :^(

The only other thing I can think of, is to let the thing sit without any power connected for a week, and try again.

Keep me/us posted.

You can also try the 68kmla.net forums.

Thanks for the help, it is much appreciated. I agree that my IIsi's condition may be terminal, especially after going through what I have already. I'll try your suggestion about leaving power disconnected for a week as I have nothing to lose. I did test the monitor by itself and it is working. Thx again.

I have two of these systems, one had the exact same symptoms you listed. Turned out the power supply went bad, I'm certain I read an article some years back that the IIsi was notorious for failing power supplies, although its been a lot of years and I may have my facts twisted. To verify, I swapped power supplies from the good IIsi to the bad one and it powered up without a hitch.

My good IIsi has a Diimo 030 50mhz accelerator card, 64megs ram, and a 1.2gig Seagate Barracuda hd. I picked up the system from a local thrift store for $10.00 and was pleasantly surprised when I got it home, opened the case and saw the extra goodies.

Neither IIsi had the ROM card, but rather had the ROM soldered onto the mother/logic board, rats!!! I could have used it in my SE/30.

Thanks for the reply, all replies are appreciated, believe me. One of the very first things I thought to replace was the power supply, which I did. It cost me $4.99 on ebay, plus about double that to ship it! The original and the replacement are both Sony. Unfortunately, my problem remains unsolved.

Were you ever able to figure out or solve the problem?

If you are interested, send me a private message. It turns out I bought a junky old LC, and got a junky old IIsi as well...anyway, the IIsi came w/o a hard drive; I'm starting to try to fix it up, but don't really have the time. If you want it let me know...