68kMLA Classic Interface
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| Apple IIc blinking power light | |
| Posted by: Arths on 2017-10-10 07:14:17 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 | |
| Posted by: bibilit on 2017-10-10 07:55:32 What kind of PSU have you been sold ? Original item is 12 Vdc at 1.2 A | |
| Posted by: Arths on 2017-10-10 08:02:14 This is the one that I bought http://www.ebay.com/itm/221294478704 Maybe I'm not using the right cable for the other hand, I'll buy a new one and try again | |
Posted by: xboxown on 2017-10-10 10:22:28This is the one that I boughtWhat is wrong with the old fashion Apple //c original brick sized power supply? | |
| Posted by: Juror22 on 2017-10-10 14:16:24 The two that I could see in the photos were 15V. I would check the outputs with the a voltmeter. | |
| Posted by: bibilit on 2017-10-10 23:23:03 Or maybe something is faulty on the other side of the PSU. | |
| Posted by: Elfen on 2017-11-18 22:55:44 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. | |
| Posted by: Arths on 2018-01-22 13:33:16 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 ? Cheers | |
| Posted by: Arths on 2018-11-03 13:22:50 Well, I’ve replaced the internal power supply as well.. same problem. I guess the computer is dead :sad: | |
| Posted by: bibilit on 2018-11-07 07:09:27 Hi, Keep in mind that the power supply is connected to the internal one :  Not saying this is the issue, but as you have a blinking led some outputs are present... | |
| Posted by: Arths on 2018-11-08 15:20:14 I’ve replaced this one too.. | |
| Posted by: bibilit on 2018-11-09 23:35:12 have you tried without disk drive ? A short somewhere ? | |
Posted by: Arths on 2019-09-01 12:06:17have you tried without disk drive ?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 | |
| Posted by: bibilit on 2019-09-01 22:21:00 I will run a multimeter, with no power connected, and see if a capacitor is not shorted. You have got two just below the psu connector and one above. Also a transistor nearby. Use the continuity test. | |
| Posted by: Arths on 2019-09-02 01:19:15 Thanks for your reply, I will try that as soon as I get home 🙂 Already measured the 7905 chip and I’m getting voltage in expected ranges, is it a good sign ? | |
| Posted by: bibilit on 2019-09-02 03:05:09 Yes. The 7905 is the negative regulator. What about the remaining rails ? | |
Posted by: Arths on 2019-09-02 08:56:52Yes. Here are my results Capacitors
Rails  Thanks a lot | |
| Posted by: Arths on 2019-09-02 10:10:54 Ok, RalfK from Apple Fritter asked me to test FFF and all I get is zero :O | |
| Posted by: Arths on 2019-09-13 10:36:22 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 ? Thanks, Arths | |
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