Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting Power Supplies and Power Supply Design
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 02-21-2016, 06:46 PM   #1
mkinn
New Member
 
Join Date: Aug 2014
City & State: Birmingham AL
My Country: USA
I'm a: Knowledge Seeker
Posts: 7
Default Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

Slight click when power button is pressed, HD spins up for 1/2 a second, then shuts down. Obviously, it is trying to power on, because the HD spins up for a 1/2 second. I don't suspect any shorted diodes or semi's. I do not have a schematic, or I could do the troubleshooting myself. Please feel free to be very technical. I have an ESR meter, and a Hakko 880 de-soldering machine.

This is a 240W power supply, and has been replaced with a newer power supply, the APPLE 661-4478, an almost identical 250W version which includes a "pressure wall" which probably has to do with airflow.


__________________
Michael Kinnaird 43+ years I.E.E.E A/V tech
mkinn is offline   Reply With Quote
Old 02-21-2016, 07:43 PM   #2
CapLeaker
Leaking Member
 
CapLeaker's Avatar
 
Join Date: Dec 2014
City & State: Atlantic Canada
My Country: Canada
Line Voltage: Ground, 0Hz
I'm a: Hobbyist Tech
Posts: 4,726
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

Since you have an ESR meter, check them capacitors. I see a few that look like they ran hot. Are there more caps under these heat sinks? Maybe check the secondaries if they are putting out. Looks like they are two 12V rails and a 24V rail.

Last edited by CapLeaker; 02-21-2016 at 07:51 PM..
CapLeaker is offline   Reply With Quote
Old 02-21-2016, 09:28 PM   #3
mkinn
New Member
 
Join Date: Aug 2014
City & State: Birmingham AL
My Country: USA
I'm a: Knowledge Seeker
Posts: 7
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

I took the power supply out.
I had to cut the heatshrink off the 2 33uf 35V caps with a sharp exacto knife.
I found the following ESR values:
33UF 35V (130) X2 - 1.0 ohms
100uf 35V - 0.5 ohms
220UF 35V X2 - .25 ohms
820UF 25V - .25 ohms
470UF 16V - .25 ohms
1000UF 16V X6 - .1 ohms
150UF 50V - .25 ohms
120uf 450V X2 - .25 ohms
All caps are RubyCon 105 caps, except the 33uf 35V ones.

Seems like they are all within spec for these caps.
Meter: Electronic Design Specialists 88A In-Circuit DCR ESR Cap Analyzer

Last edited by mkinn; 02-21-2016 at 09:32 PM..
mkinn is offline   Reply With Quote
Old 02-21-2016, 10:08 PM   #4
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 24,968
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

they dont sound in-spec to me.
what series are those rubycons?
stj is offline   Reply With Quote
Old 02-21-2016, 11:31 PM   #5
mkinn
New Member
 
Join Date: Aug 2014
City & State: Birmingham AL
My Country: USA
I'm a: Knowledge Seeker
Posts: 7
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

33UF 35V (130) X2 - 1.0 ohms - RX30
100uf 35V - 0.5 ohms - (PW)P
220UF 35V X2 - .25 ohms - (HD)P
820UF 25V - .25 ohms - ZLH
470UF 16V - .25 ohms - (PW)P
1000UF 16V X6 - .1 ohms - ZLH
150UF 50V - .25 ohms - ZLH
120uf 450V X2 - .25 ohms - BXA
mkinn is offline   Reply With Quote
Old 02-22-2016, 12:07 AM   #6
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 24,968
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

there is no way a ZLH should have esr that high.
1000/16 for example, should be 0.029 NOT 0.1
Attached Files
File Type: pdf e_zlh.pdf (128.7 KB, 92 views)

Last edited by stj; 02-22-2016 at 12:08 AM..
stj is offline   Reply With Quote
Old 02-22-2016, 01:41 PM   #7
Stefan Payne
Badcaps Veteran
 
Join Date: Dec 2009
City & State: Northern Germany
My Country: Germany
Line Voltage: 230VAC/50Hz or 400VAC/3P/50Hz
I'm a: Knowledge Seeker
Posts: 1,259
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

But is the ESR meter able to show anything below 0.1??
Stefan Payne is offline   Reply With Quote
Old 02-22-2016, 02:02 PM   #8
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 24,968
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

these need to be re-tested off-board too.
i suspect they are a bit cooked.
stj is offline   Reply With Quote
Old 02-22-2016, 02:46 PM   #9
mkinn
New Member
 
Join Date: Aug 2014
City & State: Birmingham AL
My Country: USA
I'm a: Knowledge Seeker
Posts: 7
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

Complete recap, same problem.
mkinn is offline   Reply With Quote
Old 02-22-2016, 03:47 PM   #10
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 24,968
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

make a list of the chips on the underside.
it could be an op-amp or voltage comparater on the way out tripping a false error.
stj is offline   Reply With Quote
Old 08-25-2020, 07:13 AM   #11
guruji
Member
 
Join Date: Oct 2012
City & State: mumbai
My Country: India
I'm a: Professional Tech
Posts: 61
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

i am stuck with the same smps what i want to know the pfc boosting cap what is the voltage i get 334Volts generally should be 390V.on dap017 on pin 2 i get 3volts pin no 16 just 6.2 volts.Does anyone know the valuve for zd36 near d2 & Q2
guruji is offline   Reply With Quote
Old 06-08-2021, 04:51 AM   #12
nassimhamdi
Senior Member
 
Join Date: Feb 2016
City & State: ourgla
My Country: algeria
I'm a: Knowledge Seeker
Posts: 102
Default Re: Apple 24" iMac A1225 EMC2134 with a Delta ADP-240 AF B SMPS, won't start

what a bout ic's voltages???
nassimhamdi is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2021
Powered by vBulletin ®
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 11:50 PM.
Did you find this forum helpful?