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Re: Recapped PowerMac 8100 PSU and now unstable
So I pulled that cap and some of the blue ones and the other larger gray box one as well. My ESR meter couldn't read them because they are just too low capacitance (0.1µf, etc), but my DMM at least verified their capacitance to be good. As for the high ESR reading, that was in-circuit and it was misreading as the capacitance reading was off as well.
Should I just shotgun replace some of these? I'll keep pulling the filter caps up to and including those around the massive ones.Comment
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Re: Recapped PowerMac 8100 PSU and now unstable
no, check the 2 big filter electrolytics next.
i know you replaced them - but i dont know what withComment
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Re: Recapped PowerMac 8100 PSU and now unstable
I’ll do that. One thing also to remember is this problem existed prior to my changing out the caps. The problem existed 20 years ago when I acquired the machine, I just never got around to it till now!Comment
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Re: Recapped PowerMac 8100 PSU and now unstable
Sounds like maybe the PSU temp is too high. (or a thermal sensor problem)ASRock B550 PG Velocita
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Re: Recapped PowerMac 8100 PSU and now unstable
Re CX1, measuring its capacitance in circuit will include any other X caps in parallel with it. So, for example, if there's a .47uF that is also across the AC line your .1uF cap will measure ~.57uF.PeteS in CA
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Re: Recapped PowerMac 8100 PSU and now unstable
caps across the line usually have a parallel discharge resistor too.
that will make it read higher.Comment
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Re: Recapped PowerMac 8100 PSU and now unstable
I took that box cap out and it tested fine. Now, I have removed the blue disc caps and tested them out of circuit with the DMM, and they all test within tolerance for their specified capacitance. They are all far too small to test ESR. I tested the large filter caps, both published at 680µf, both with 0.17 ohm ESR, one 601µf, the other 592µf, so all around good. I also took out and tested the thermistor within the circuit...It appears to be rated for 7 ohm (it is 15SP M007), and tests at 11 ohm.
I can test more ceramics as I go, but I m running out of ones to test at this point.Comment
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
This specification for the HP Compaq Elite 8100 SFF can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Compaq Elite 8100 SFF boardview and Compaq Elite 8100 SFF schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...09-12-2024, 03:44 PM
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I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
First of all, thank you everyone who helps others in here! You guys are treasures! Please bear with me, this may be long. I have tried a LOT.
First, my wife said the TV was turning off and on. When cold it would be fine for several minutes, then it would start resetting.
I opened it up and noted there are two main lines coming out of the supply besides the backlight., The T-Con 12V line and the main 12V line.
TRIED 1 - I scoped power coming from Power Supply while it was all still connected. I noted that just before it reset, the 12V line going to the T-Con was going... -
The sub developed a constant popping every couple seconds from woofer and power LED flickering with nothing but wall AC connected. Connecting an audio cable didn't change anything. It doesn't play but a second or two of audio in between the pops.
Opened it up and discovered the power supply is making a faint clicking or ticking sound.
I measured the amp's output to the woofer and it pulses up to 50mv DC to be driver. The pulses coincide with the power supply ticking/clicking.
I measured the power supply output going to the amp board and it too has this pulsing. Voltage cycles...
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