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Power Supply dead
- Thread starter Vifa
- Start date
Dwight Elvey
Veteran Member
patscc
Veteran Member
Power Supply
Power Supply
Power supply to what ?
patscc
Power Supply
Power supply to what ?
patscc
tezza
Veteran Member
Check the voltages, when the power supply is plugged into the motherboard and under load. See if they are correct.
Details are in redbook.pdf (page 110), which can be downloaded from http://apple2history.org/dl/dl.html
Tez
Details are in redbook.pdf (page 110), which can be downloaded from http://apple2history.org/dl/dl.html
Tez
channelmaniac
Veteran Member
There are 2 versions of the Apple II+/IIe power supply - an Astec and non-Astec model.
Please post which one you have.
The non-Astec tends to need a cap in the feedback section and a 22 ohm 1/2w resistor replaced.
The Astec one tends to need a 220uf @10v 85 deg C cap replaced in the feedback section as well... (C7)... Replace it with a 220uf @16v 105 dec C cap.
BEWARE: The non-Astec supply DOES NOT have bleeder resistors across the main filter caps. If they are charged it takes a LONG time to bleed off and represents a major shock hazard. It's DC voltage which will cause your muscles to clamp down, making it hard to release that board.
Yes, I had 2 scars on my hand that took about 9 years to fade out from one of those non-Astec ones.
If those aren't the fix, let me know. I've repaired a lot of those over the years when I used to work for a grey market Apple repair shop.
RJ
Please post which one you have.
The non-Astec tends to need a cap in the feedback section and a 22 ohm 1/2w resistor replaced.
The Astec one tends to need a 220uf @10v 85 deg C cap replaced in the feedback section as well... (C7)... Replace it with a 220uf @16v 105 dec C cap.
BEWARE: The non-Astec supply DOES NOT have bleeder resistors across the main filter caps. If they are charged it takes a LONG time to bleed off and represents a major shock hazard. It's DC voltage which will cause your muscles to clamp down, making it hard to release that board.
Yes, I had 2 scars on my hand that took about 9 years to fade out from one of those non-Astec ones.
If those aren't the fix, let me know. I've repaired a lot of those over the years when I used to work for a grey market Apple repair shop.
RJ
channelmaniac
Veteran Member
I almost forgot...
Try this thread:
http://newlifegames.net/nlg/index.php?topic=23.0
It's a thread in my repair logs on repairing switching power supplies.
RJ
Try this thread:
http://newlifegames.net/nlg/index.php?topic=23.0
It's a thread in my repair logs on repairing switching power supplies.
RJ
channelmaniac
Veteran Member
OK.
Turn it on and listen carefully. Put your ear up to it. Do you hear it making a soft chirping sound? If yes, then you have a bad cap in the regulation part or you have a shorted diode on the output section.
If not, you'll have to troubleshoot it further.
You'll need to drill out two small rivets on the supply to open it up. If they are gone then someone else has already worked on it.
Open it and check the fuse. If the fuse is blown then you probably have a shorted bridge rectifier that needs replacing. Check it for shorts with a digital multimeter on the continuity setting.
It's pretty rare for the TO-3 case (big!) transistor to short out. Generally it's the bridge rectifier.
If you don't want to repair it, I can do it for you for a nominal price.
RJ
Turn it on and listen carefully. Put your ear up to it. Do you hear it making a soft chirping sound? If yes, then you have a bad cap in the regulation part or you have a shorted diode on the output section.
If not, you'll have to troubleshoot it further.
You'll need to drill out two small rivets on the supply to open it up. If they are gone then someone else has already worked on it.
Open it and check the fuse. If the fuse is blown then you probably have a shorted bridge rectifier that needs replacing. Check it for shorts with a digital multimeter on the continuity setting.
It's pretty rare for the TO-3 case (big!) transistor to short out. Generally it's the bridge rectifier.
If you don't want to repair it, I can do it for you for a nominal price.
RJ
Druid6900
Veteran Member
Warm is OK, there is no fan. It's planned that way because it keeps the ROMs from icing up.
Supernovae, on the other hand, is very, very bad.
patscc
Veteran Member
Infrared
Infrared
Sure wish I could see infrared.
patscc
(Sorry, bad jole)
Infrared
Sure wish I could see infrared.
patscc
(Sorry, bad jole)
Terry Yager
Veteran Member
patscc
Veteran Member
Stinker
Stinker
That's almost as smelly as Lutfisk.
Good one.
patscc
Stinker
That's almost as smelly as Lutfisk.
Good one.
patscc
I don't think I can hear anything when I turn it on/off with the switch; but I can for sure hear something when I plug the power cord into it. Hard to explain what it sound like, not something big, but something is making a sound.
I really appreciate that, but unfortunately I live in Denmark and was hoping to find someone nearby me, it will be easier that way.
Anyway, I can't seem to find anyone who can fix this, so I will keep you in mind. In case I don't find anyone at all, can I then send the power supply to you by mail?
channelmaniac
Veteran Member
Yep.
If yours is the model with rivets on the side, drill or cut them out, take the screws out, and disassemble it. That way you can send just the board to save on shipping costs.
Before you do that, can you post a picture of the inside of the power supply? There are a couple of parts you can easily replace to try to fix it first.
RJ
If yours is the model with rivets on the side, drill or cut them out, take the screws out, and disassemble it. That way you can send just the board to save on shipping costs.
Before you do that, can you post a picture of the inside of the power supply? There are a couple of parts you can easily replace to try to fix it first.
RJ
Hey there again. I have just removed the power supply, and tried to open it. Here comes some pics.
Attachments
Funny thing, I found a date on the bottom of it - it reads "MAR 9 1979". That means it will soon turn 30, that just settle a deadline for my project; my Apple has to be up running again before so I can celebrate the birthday in a proper way...
Anyway, I have removed all the screws in both sides, it looked like the bottom of the power supply then would come off. I can move the bottom panal a very little bit up and down in one of the sides, but I can't seem to remove it completly? Do I have to remove the rivets too? - even though the rivets don't seem to hold the bottom.
Do you have a picture of a power supply which has been opened?
Vifa
Anyway, I have removed all the screws in both sides, it looked like the bottom of the power supply then would come off. I can move the bottom panal a very little bit up and down in one of the sides, but I can't seem to remove it completly? Do I have to remove the rivets too? - even though the rivets don't seem to hold the bottom.
Do you have a picture of a power supply which has been opened?
Vifa
channelmaniac
Veteran Member
Drill out the rivets or use a small set of side cutters to cut the heads off so you can open the supply.