Re: What's wrong with my power supply?
If Im asking here is because I have checked all those articles, and I didn't have an answer to my problem. But as I said thanks anyway...
sbyseven
Member
Last Activity: 04-02-2023, 02:02 AM
Joined: 03-25-2016
Location: Málaga
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Re: What's wrong with my power supply?
thanks, but that's a completely different problem that I have...Leave a comment:
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Re: Samsung Curved monitor C27FG70FQU with garbled vertical lines on startup
I had a monitor with that problem and it was because of the flex cable.Leave a comment:
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Re: Apple cinema display A1316 takes forever to turn on!
I had the same issue and later on, the power supply went off. I changed all the taicon capacitors but that didn't solve anything.Leave a comment:
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Re: What's wrong with my power supply?
It is fluctuating sometimes I get 4v sometimes less from each pin but I can't get the 24v to the motherboard...Leave a comment:
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Re: What's wrong with my power supply?
Hi thanks for the reply. I'm a newbie how can I check that without danger? Is there any passive way to check that? I mean without connect it to the socket...Leave a comment:
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Re: What's wrong with my power supply?
First, thanks for the prompt reply.
1. Are you measuring the voltage on the 420V caps directly across their leads?
- Yes, I'm measuring them as shown in the picture.
2. These might be sense resistors for the APFC boost circuit. They should read very low resistance. If open-circuited, that could be the reason why you don't see any voltage on the 420V caps.
- Ive measured them and they gave me 0.004 Ω each one. Do I have to change them?
3. Last but not least, I hope you haven't...Last edited by sbyseven; 02-20-2023, 07:09 AM.Leave a comment:
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Re: New Members - please post your introductions here
Hi everyone I’m a electronics newbie that wants to learn a lot from you guys,
I’m from Spain sorry about my EnglishLeave a comment:
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Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead
I have found this:
[url]https://www.instructables.com/Fixing-Clicking-Noise-Problem-on-Apple-27-Display/[/url]Re: Apple Cinema Display 27" No TBol...Display/[/url]Leave a comment:
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What's wrong with my power supply?
Hi folks, I have a power supply from an Apple Cinema Display 27 that is not giving me dc output correctly.
Things that I have done already:
1. Change all the Taicon Caps but nothing has improved.
2. Change a Zener diode rectifier, but nothing has changed.
What I have observed is that Rubycon caps 420 68v are not passing more than 10v and fuses are not gone.
Where can I begin diagnosing a power supply?
Any help is welcome.... -
Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
The Diode is working fine so must be a short near that zone. Any advice?Leave a comment:
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Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
After changing all the capacitors because I read it (facepalm)
I have discovered a Zener diode that is shorted, so Im going to change it tomorrow and let you know if it works....Leave a comment:
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Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
Some of the caps are difficult to see the specs if you don't desolder them For those who want to know the capacitor's specs here they are:
470uf -35V
1000uf -16V
330uf -35V
4,7uf - 50V
22uf - 50V
2,2uf - 50V
220uf - 50V
47uf - 50VLeave a comment:
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Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
The fuses are not blown, so I think the bridge rectifier cannot be. So where else could I check?tiaLeave a comment:
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Re: MAC Display A1316/A1407 appears to be dead even after replacing the PSU three tim
I have the same problem, did you check the capacitors? I have changed them all but I don't have dc output.
Be careful with this power supply because there are 3 capacitors that are 420 68uf and could be dangerous. If you can upload an image I can show you what I have checked but mine is still dead....Leave a comment:
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Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
Thanks for the prompt reply, I didn't see it until now.
I'm a total newbie on Power supplies, can you show me where is the bridge rectifier in these pics? Tia...Leave a comment:
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Re: Apple A1407 Thunderbolt Display Power Supply PA-3251-3A
Hi Sam I have the same problem and I have changed all the electrolytic caps, except the 420v 68uf ones, I have checked the fuses but they are ok, but I don't have dc output, and what I can see is that the 420v are not charging more that 10v or so if I leave the board connected for 1 hour, everything seems to be good under the microscope, where else could I check? Tia...Leave a comment:
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