adelage
Member
Last Activity: 04-08-2025, 04:29 AM
Joined: 12-01-2019
Location: terrasini
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Ok, I managed to get it done somewhere else, thanks anyway! 😊... -
Bios dump with ch341a
[ATTACH]n3590692[/ATTACH]
bios cap from ecs website
[ATTACH]n3590693[/ATTACH]Bios dump with ch341a
[ATTACH]n3590692[/ATTACH]
bios cap from ecs website
[ATTACH]n3590693[/ATTACH]...Leave a comment:
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Merge ECS Z77-H2 bios cap file with original dump
Hi,
I am trying to recover an ECS Z77-H2 motherboard, I dumped the original bios with a ch341a programmer, the bios from the manufacturer is a .cap file of smaller size, and it seems that I need to merge this file with other information from the dump, anyone can explain how to do that? -
So, I tried to calculate the zener diode using some online calculator, and the power rating for the diode is supposed to be almost 400w! I put 318v as input, 300v as output and 0.5A as load current..either I am using the calculator wrong, or I misunderstood the way a zener diode works..Leave a comment:
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The led strip is cheap and rather inefficient, composed of just leds and resistors, that’s why it consumes a lot of power, the box says it consumes about 12w/m, and it’s 12m long, so in total we it uses about 150w (at 310v rectified around 5A).
One important detail I forgot to mention:
the strip is controlled by a triac dimmer device before the rectifier (which works both as a dimmer and as a relay), and without the capacitor, once I dim it down, the light flickers noticeably.
Also, I would like to keep the solution as simple as possible, and at the moment I have no idea...Leave a comment:
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Do you believe an inductor in series, together with the cap, help?Leave a comment:
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I tried with a 450v/680uf (massive cap) and it's a bit better, but it still flickers..also, the led strip gets quite a lot brighter...Leave a comment:
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220v Led strip flickering
Hi, I am installing a long led strip and I noticed that it frequently flickers slightly, it is not a strong nor regular thing, but it is noticeable and annoying. I have measured the voltage of the mains and it shows some fluctuations, it normally stays at around 226v, but often (every few seconds) drops down to 218/219v), and the flickering happens exactly at the same time. I have measured this at the counter and with every appliance off, so it's not related to the house electrical system, but that's how it comes from the supplier.
I know that the best solution would be to get a voltage... -
Boardview/schematics g513qy
Hi, I am looking for the boardview (and possibly schematic) for an Asus Rog g513qy,
Thanks. -
Re: Atx psu 5Vstb present, no output
Just a quick update, I put back the resistor on r14, and I managed to test the frequency of the pwm output (pin 7 and 8), and I found out that the ic was actually switching, so I checked the main bjts on the hot side and one was actually giving some strange readings, so I replaced them both, and after that the ic stopped switching (same as the beginning) so I had the amazing idea to cut all the tracks (1 to 4) for the ovp protection pins and short them to ground, and turn it on without any isolation transformer nor incandescent bulb in series...Last edited by adelage; 11-20-2023, 05:29 PM.Leave a comment:
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Re: Atx psu 5Vstb present, no output
R18, believe it or not, was like this when I opened it (and the psu was bought new a few months ago), I tried to solder it but nothing changed, so I put back the way I found it, R14 was taken out to measure it when I took the picture, I am checking pretty much every single component just to find if anything is burned or shorted...Leave a comment:
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Re: Atx psu 5Vstb present, no output
Sorry I had a couple of busy days and couldn't reply before..
Anyway here are some pictures of the board, as per your suggestions: all the electrolytic caps look fine (I only checked capacitance since I don't have an esr meter), I couldn't find any bad solder joints anywhere, and I checked all the bjts and the main diodes on the board and everything seems fine, now I will have a look again in case I missed something.
Btw, I know it's not worth fixing it, but I am just studying and learning how to fix power electronics....Leave a comment:
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Re: Atx psu 5Vstb present, no output
Unfortunately I am at home now so I can’t provide any pictures, will do it tomorrow.
The psu was pretty much new, it suddenly stopped working without any particular symptom,it is a bog standard chinese model (2 big caps in series with 2 bjt), the 5v standby circuit works fine so I didn’t need to test the optocoupler and its feedback circuit (at first I tried replacing the optocoupler and the tl431 just in case, but the readings on both sides remained identical as before), the voltage on the green wire is 5.2v (before...Last edited by adelage; 11-10-2023, 02:22 PM.Leave a comment:
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Re: Atx psu 5Vstb present, no output
There's only one optocoupler for the 5Vstb line which works fine...Leave a comment:
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Atx psu 5Vstb present, no output
Hi guys,
I am currently trying to fix an atx psu which has 5v stb present, but doesn't turn on when shorting the pson wire to ground (I have tried with and without load), the pwm/supervisor is a est7502 (which I have replaced), I have checked every diode, every transistor and every cap and they all look fine (capacity wise, I don't have an esr meter yet), the only anomaly is the second voltage (is it called bias voltage maybe?) coming out from the standby transformer, which reads 13.5v (I believe it should be above 15/16v), any suggestion on what to check next? -
Re: New Members - please post your introductions here
Hi, my name is Vince, I’m from Sicily and I have been tinkering with PC stuff and gadgets since when I was a kid, building PCs and trying to swap their parts to see if they could work again (or better)..30 years later I am trying to step up (thanks to a “dodgy” Romanian guy called Sorin that you can easily find on youtube), wishing to get decently good at board level repair..Leave a comment:
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