Sorry for the late reply.
No, I don't think it is. I pressed hard on the SIO and in the arena near the PS_ON switch but nothing changed. I also tried to gently bend the board but to no avail. It's not possible that somehow an bad transistor does this. It would either be completely on or off if it was broken.
it couldn't be damaged by an scrapper since I got the PC with everything and it died on its own while I was away.
Any ideas?...
kotel studios
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Last Activity: Today, 01:13 PM
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Epox EP 85 MVP3C-M - 3.54v Vcore regardless of jumpers
Hi,
Recently I got an Epox EP-85 MVP3C-M board from scrap. After fixing the broken caps I powered it on without CPU and the jumpers set to 60Mhz FSB and 2x multiplier.
Sadly, Vcc3 was stuck at 3.54v regardless of jumpers. Vcc2 (Vi/o I think) was also the same voltage.
So, I've returned to the original configuration I got the board in - 100Mhz FSB and 4x multiplier. Voltages haven't changed at all.
What I've tried so far:
replace the original N-MOSFETs with beefier 60V ones for testing
Resolder the resistors near the Vcore Jumper block
Short Vcore...Last edited by kotel studios; 05-25-2025, 03:02 AM. -
Uploading the drivers for the SAA713x chip tuners and the K!TV 2.3.0.1 software which seems to work....Leave a comment:
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Modify Acer V65X BIOS to initialize the CS4237B chip
Hi,
Since the ACER V65X doesn't have the onboard CS4237B audio and my own V65XA BIOS is toast, I need some help trying to figure out how am I supposed to put the init instructions from lets say an Acer V58XA with the same audio chip into the V65X BIOS.
Anybody who could be kind enough to at least seperate the part where V58XA initializes the sound chip?
Attaching the V58XA and V65X BIOS'es in the zip files.... -
Well, it might've been the case earlier on, now this board is total e-waste....
Not only did I order the wrong chip (ADP3166), I also destroyed pin 11 (EN) on the original chip and the pads bellow them onboard......
Sure, trace repair is possible, but is it really worth putting in another 50zł just to not have a guarantee if it's not gonna work?...Leave a comment:
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Okay a little bit more info, the V65XA also exists under Aptiva 2138-E76 PC.Leave a comment:
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MSI 845PE Neo (MS 6580 V3.0) - BIOS needed
Hi,
Just as the title says I need the BIOS file in .BIN format for an MSI 845PE Neo (MS 6580 V3.0. All I can find is the updater soft for DOS and one DTK OEM BIOS which doesn't work (or my board is just dead).
The files from the DOS updaters are missing the BIOS strings, so idk if they'll work. -
After some troubleshooting I found the culprits, missing FB, FBRTN, PWRGD which makes the VRM not switch (no PWD 1-4 voltage). FB and FBRTN are all connected to their respective rails. Injecting FB makes PWRGD still stay low....
Injecting Vcore directly onto the coils makes the CPU get out of reset, but it's still not posting...
All I know is that the ADP3168 sees some unknown fault and halts the switching of the VRM and that's it.
Any ideas?
Leave a comment:
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Intel D865PERL - no Vcore after replacing MOSFETs and MOSFET drivers
Hi,
Finally got time to fix this board up.
At first it didn't give any POST codes. Turns out it was an unsupported Celeron D cpu. After dropping in an Celery 2.6gHz the CPU came out of reset with clock signal, but still no post codes. For a while it did work when I applied pressure to the ADP3168 chip, but on next reboot the MOSFETs started to burn. Then I left it as is for months.
Now I came back prepared. Replaced the bad MOSFETs and the ADPxx18k drivers. Now I don't get any MOSFETs blowing up issues anymore. But sadly, the Vcore is missing. The whole VRM isn't...Last edited by kotel studios; 04-22-2025, 06:16 AM. -
Okay under general load (as I would run it) the cpu 12.8v goes down to 12.66v and [i]seems[/i] to be going slowly up. So ig it should do the trick.
Generally this whole repair could've been avoided if I cleaned this PSU and waited like 6 months before testing it without a sacrificial board.Okay under general load (as I would run it) the cpu 12.8v goes down to 12.66v and [i]seems[/i] to be going slowly up. So ig it should do the trick.
Generally this whole repair could've been avoided if I cleaned this PSU and waited like 6 months before testing it without a sacrificialLeave a comment:
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Okay, since everything seems to work fine I decided to rework the case a bit and guess what? The 4pin CPU power is proprietary. Instead of 12v or 12.4v high power it's 12.8v (no load is 13.20v while with an 12v 5w bulb it's 12.9v)...
I'm not gonna write about "downgrading" the rail here since this post was just to fix the screeching noise.Leave a comment:
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UC3845B PWM chip. I think it was ground with output shorted. Gotta recheck once I get to finalization of this repair.Leave a comment:
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Yep, it was the short on the dip 8 component at fault. Or that and the out of spec 220uF 25v cap. Odd since there wasn't any short before on it.
Now the PSU works without any fuss with the original caps. I will do further testing to confirm whether this PSU is safe for normal use.Leave a comment:
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Actually, after removing all of the transistors I noticed the dip8 component on the primary side had two legs shorted. Odd, don't think I've done that while desoldering the transistors and whatnot...
And now after putting everything back together I get no life at all from this PSU. Not even the bulb protection. I guess the 230vac wires got screwed.Leave a comment:
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Overloading shouldn't be the issue. The board takes waaaay less than 180W the PSU is rated for.
Old caps in and the original fan and still the same issue. 12v is 11.84v.
I think the sound comes from near the transformator. If it had shorted windings then the PSU wouldn't start up right?
I will need to pull out the transistors near it and check them out of circuit (in circuit they are fine).
I am running out of ideas now. I should also replace all of the smaller caps on the secondary side, but who knows if that'll help....Leave a comment:
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Primaries were replaced but the sound is still there..... So this can't be the primary side. Gotta take a closer look at the secondary or better yet, put the original caps in....Leave a comment:
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Okay still same sound, even after replacing an 10uF 50v cap connecting to 5v rail (I didn't see that one of the legs was broken). Maybe even worse. This time I measured 5v rail and it was 5.14v
Another idea would be that the primary caps are cooked and need to be replaced, but the only 470uF 200v caps I have report as 320uF which is not normal (they are from an LC clone). I think for testing they should be enough.
Any ideas?Last edited by kotel studios; 03-26-2025, 09:07 AM.Leave a comment:
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I don't think it's the first assumption since I used the same caps as with my LC clones, but who knows what hp did with their stupid engineering.
lcr t2 tester. Sure, it's nor that reliable but it gives me an rough example of what the real capacitance should be. ESR is always 0ohm (tester limitation) and V loss is either 0.2% or 0%.
...Leave a comment:
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Compaq PDP-124P - loud screeching when running
Hi,
Recently I got my compaq PDP-124P to "work" and it now screeches loudly when running (you can hear it from 60cm away!).
There's nothing shorted on it, caps were already checked and replaced when they were close to being above 20% of rated spec, apart from the primaries. Fan isn't the issue too.
I didn't have time to measure the voltage rails (beside 12V, that one had 11.7V) due to the unexpected sound.
Load was only an single sacrificial board w/o CPU power since these PSU's don't work without mainboards.
Any ideas what could be... -
That would indicate the coupling caps being bad. Recheck them if they are okay....Leave a comment:
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