Re: psu ac240as-01 dell Optiplex 7010 pc tower
I'm sure stj gave me the right values for C6/C10, on one of these caps I saw 300 (or 333nF) at 1KV, stj recommended one 680nF at 2KV for these 2 caps, which I did on every PSU I have left. Hopefully the broken C6/C10 caps are the reason for the PSU failing (I saw also broken C6/C10 caps, but the PSU was still working!).
Sorry, I'm not sure how to isolate or find the "snubber network"? But I didn't find any great different values by measuring (via diode mode) and comparing the values of the components of the primary...
matser
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Last Activity: 04-20-2025, 12:17 PM
Joined: 04-19-2012
Location: Klagenfurt, Carinthia
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Last edited by matser; 12-01-2022, 02:55 AM. -
Re: psu ac240as-01 dell Optiplex 7010 pc tower
@stj: The fet is shorted again. I don't think the CM6800 is bad (the new one shows nearly the same values at meassuring without fet, as the old one). I have another fet in reserve, but as long as I don't know the real guilty part, it doesn't make sense to give it another try. I meassured and compared (diode mode) every part of the primary side with a good PSU and didn't find any differences. OK, there where some differences at the voltages of CM6800 but why isn't clear to me (as I mentioned, I'm not a electronic technician). Where do...Last edited by matser; 12-01-2022, 01:23 AM.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
First it works, then I put the PSU in the PC, also works. I go the BIOS, then I try to reboot and the room was dark. At the moment I'm not in the mood to disassembly it once again and take a look if the fet is shorted again.
Anyway thanks for your help stj, I think I give up now.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
OK, then I will give it a try without lamp.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I've tried it also with a 100W lamp, nearly the same, but I forgot to mention, that I also have connected a HDD. Without this HDD, the fan is spinning, but the green LED on the backside shows no light neither with the 60W nor the 100W lamp. Also there is a fizzing sound coming from the PSU.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I have 5V on the violett cable of the ATX connector.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
The new CM6800 arrived today, I soldered it in and also connected a 60W lamp bulb in series with the power main in, also I shorted the green/black cable of the ATX connector to switch on the PSU. After connecting with main power, the lamp bulb goes on and off, also the PSU does so (fan begins to spin, slow down, spins... so did also the green led on the back side of the PSU). The fet still seems to be ok, after this test.
Is this a sign, that I may try it without the lamp bulb, or is there still something wrong?Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I suppose to buy a new CM6800 and try it with this one, then I can leave the working PSU as it is.
Where should I connect the 60w lamp bulb?Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
It's the name: Mc Voice M-930LLeave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
Unfortunately it seems to me not, only V, A, Ω and hFE....Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I found only a small SMD capacitor. Measuring with diode mode shows the same values on both PSU. Measuring farad seams not to work soldered in, shows 0 also on both PSU.
@pins 11 & 12: OK, but I only have a multimeter and a second one for measuring capacitors.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I appreciate your help very much stj, thanks!
I compared now the values of CM6800 on both PSU, there are some big differences. What I should mention is, that I have connected a consumer (HDD) on the good PSU!
Pin...Bad PSU....Good PSU
01:....7,26..........0..........IEAO
02:....1,5...........1,4
03:....0..............0
04:....4,8............3,6.......VRMS
05:....9,84..........0..........SS
06:....3,95..........2,59.....VDC
07:....2,56..........2,52
...Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
On the bad PSU I put out the mosfet plug it in and compared with the good PSU I found a difference on a transformer on pin 3 (see attached picture) between good and bad PSU. The other voltages I found, where exact or nearly the same between both PSU.
Transformer bad PSU
pin 1: 312V
pin 2: 1.590 up to 1630V
pin 3: 306V
Transformer good PSU
pin1: 312V
pin2: 1.600 up to 1670V
pin3: 462V!
On IC CM6800 where no voltages measurably. But I haven't tried to switch it...Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
If I understand right, I put out the mosfet, plug the PSU in and meassure the voltage on the CM6800 and can the values compare with the working PSU?Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
@glue: everything is white, so should also be ok.
I meassured once again between PVM out (CM6800), gate of blown (now new) mosfet and also all pins of the 4 transistors I found (Q100, Q101, Q102 and Q103). Every meassuring shows nearly the same values (max. 10Ω difference) between good and bad PSU. No direct connection, the lowest resistance is between PVM out and gate (40Ω - same on good and bad PSU!).
It's frustrating to find no differences at meassuring between good and bad PSU. I think I meassured...Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
With meassuring I didn't find any relevant differences between the bad and the good PSU?! Could it be, that this white glue on some components gets conductive after some years? I remember that I have this in the past on a PSU of a Samsung monitor.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
Thanks for the info stj, no short between PWM out and Gnd, Vcc or Vdc, every meassuring shows nearly the same values on bad and good PSU (meassuring in diode mode, IC CM6800 soldered in).
Also meassuring on CM03X shows no relevant differences with bad and good PSU.
Am I right, that the problem must be on the primary side of the PSU?Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
Sorry, but I‘m not sure how to find the driver. I checked also IC TNY280PN because it was mentioned in a thread as faulty at a similar PSU, but it shows the same values as on the good PSU (of course soldered out).Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
I have soldered in a new mosfet now and compared the bad with a good PSU with some meassuring, but can‘t find any big differences. I don‘t want to burn the new mosfet again and I‘m wondering what to check next.Leave a comment:
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Re: psu ac240as-01 dell Optiplex 7010 pc tower
No not until now. My plan is to solder in a new mosfet and then I'll compare the bad PSU with a running PSU and do some meassuring. Optical I didn't find a burned chip.Leave a comment:
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