Jump to content

Apple IIc blinking power light

Recommended Posts

Hey guys,

Had an Apple IIc for almost 3 years but it did not came with a power brick.

So I decided to buy a Toshiba charger transformed into a IIc power brick off eBay, the problem is when I'm turning on the computer the green power light is blinking and I'm not getting any startup beep. The disk drive is not running as well.  :'(


Any ideas ?

Best regards

Edited by Arths
Link to post
Share on other sites
  • 1 month later...

How is the Toshiba PSU connected to it?


Check your connection and your PSU, I do not think it is strong enough to run a IIc. The IIc needs 12 - 15 volts, you can run off a Lead Gel Battery if in a pinch. It is a Power Hog. Check.this video out: 


Includes a pin out for the power port for you to verify.

Link to post
Share on other sites
  • 2 months later...

Okay guys, sorry for the late response.

I’ve been very busy for the last few months but finally got a my hands on a multimeter :-)


Well everything seems to be okay concerning the 15V power pins. I guess there must be something wrong with the internal power converter :-(

Interestingly enough it sometimes seems to be starting up, floppy drive led is solid red and I can hear the speaker cracking a little bit but nothing more..


Maybe dead condos ?


Edited by Arths
Link to post
Share on other sites
  • 9 months later...
  • 9 months later...
On 11/10/2018 at 8:35 AM, bibilit said:

have you tried without disk drive ?


A short somewhere ?

Sorry for the late response :(

Yes I’ve tested without a disk drive and it still won’t boot.


What should I check first ?

Is there a place on the board where I can check that the voltages are the ones I shall receive ?

Thanks for your patience


Link to post
Share on other sites


6 hours ago, bibilit said:



The 7905 is the negative regulator. 


What about the remaining rails ?


Here are my results 




  • C57 shows zero
  • C44 and C43 shows infinite when speaker is unplugged, .845 when it is






Thanks a lot

Edited by Arths
Link to post
Share on other sites
  • 2 weeks later...

Hey guys,


Turns out it was the LM311N chip which was causing the blinking power light.

Soldered a new one and blinking is gone but it still doesn't want to boot.


Hooked the IIc using the composite output and here is what I get..



Sometimes I get scrolling characters instead like so



Holding CONTROL-RESET makes the scrolling stop so I guess the CPU at least understands the keypresses.

Any idea ?






Link to post
Share on other sites
  • 4 weeks later...

Hi guys,


Just received the chips, tried piggybacking but that doesn’t seem to change anything. :/


Maybe there are specific chips I shall try this method on ?


If you have any idea, please let me know :'(



Edit : Piggybacking F18 makes horizontal white bars but that's it



Edited by Arths
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...