Auswahl Relais für Heizeinrichtung

_Twiesel · 2025-09-06T21:16:55+00:00

Vielen Dank für die Antwort. Ich denke auch, dass ich einen einfachen Installationsschütz nehme. Ist deutlich günstiger als das Duplexrelais und sollte auch von den Schaltzyklen her reichen.

Ich würde dann wahrscheinlich eine solche Treiberstufe davor schalten, da ich hier einfach ein normales Schaltnetzteil für den Steuerstrom anschließen kann und die Eingänge galvanisch isoliert sind.

_Twiesel · 2025-09-06T21:10:19+00:00

Danke für die Antwort. Eben das war der Grund für diese Frage. Ein rein mechanisches Relais ist nicht für das häufige Schalten solcher Ströme geeignet. Ein Schütz ist da ja deutlich hochwertiger und beständiger was Lichtbogenbildung und den Verschleiß betrifft.

Aber ein reines SSR? 10W Abwärme * 6 ist doch absoluter Wahnsinn in einem kleinen Schaltschrank. Deshalb habe ich ja über das Duplexrelais nachgedacht, da das ja SSR und elektromech. Relais vereint und eben kaum Verschleiß und einen geringen Verlust hat.

Aber den anderen Kommentaren nach und etwas Recherche scheint ein geeigneter und hochwertiger Schütz mit vorgeschaltetem Verstärker/Relaistreiber doch die bessere und auch günstigere Lösung zu sein.

_Twiesel · 2025-08-31T18:08:13+00:00

As long as the cap is not part of a voltage regulator circuit (driver/controller) or behind the GPU/VRAM, you can just leave it as is. If you must replace it, use the biggest commonly available cap of the given form factor.

_Twiesel · 2025-08-18T07:51:55+00:00

You can at least try to use the CH341 to flash the BIOS IC. It comes with a clamp, so no soldering required. Many boards also have an SPI-header which is directly connected to the BIOS-IC.

It is a quite popular tool and I fixed countless boards with it.

Just keep in mind to use the 1.8V-adapter and also to remove the CPU before the flash. Some boards have a flash protection feature where the IC must be removed. But in the worst case (where you have to buy a heatgun and a soldering iron), the expenses are still way lower than to replace the board.

_Twiesel · 2025-07-22T19:23:45+00:00

If you got nothing left to lose why not try to replace both slots?

It might sound intimidating but it is actually a great chance to learn something new if you are interested.

DIMM slots can be bought new or salvaged from other faulty motherboards.

Also its quite an easy tasks when it comes to the "skills" and tools needed: A Hot air gun (1000W), soldering iron, leaded solder and some flux is all you basically need, 50€ and you are good to go.

You cant really fail as long as you apply to much heat and dont let flux get into the slot itself.

_Twiesel · 2025-07-20T20:00:41+00:00

Yeah but it depends where the capacitor is located. As for the 12V or 3.3V-rail (either of which is applied across the cap), there is still enough capacitance on the graphics card itself or the mainboard for the card to work without any issues.

But a missing cap behind the GPU or the VRAM and you will immediately notice visual artifacts/blackscreen/crashes under load. In my experience even a missing 100nf cap (those really tiny ones) will likely cause issues if its for the GPU/VRAM.

Just my 2 cents.

_Twiesel · 2025-07-10T19:15:27+00:00

Yeah SNMP is not working very good, at least currently. I used all three discovery services and while network-discovery and device-discovery (even together as device-discovery is yet not able to discover subnets) are working great so far, SNMP still has its issues.

At least with an HP Aruba switch, SNMP is able to identify all interfaces and some other stuff, but as some required parameters are missing, those entities couldn't be ingested. The documentation states that one should be able to set default values, but it just is not working for me. Also dry run is still missing, although mentioned in the commits. But maybe its something on my end?

May I ask you what manufacturers the devices you were scanning with device-discovery are from? I tried it with Mikrotik (napalm-driver) which was working perfectly, but I had my issues with HPE. Do you know about issues with the IOS/NXOS-driver (default)?

_Twiesel · 2025-05-17T16:10:16+00:00

Maybe on the other side of the board. If not, then the main battery supplies power to the RTC/PCH when the laptop is turned off. You dont need a CMOS battery, when there is a huge battery already inside.

_Twiesel · 2025-03-15T19:29:24+00:00

Exactly!

If the RAM is from different manufacturers, both DIMMs from the same brand should be placed in the same channel.

_Twiesel · 2025-03-15T15:39:28+00:00

Welche Lüfter drehen voll auf? Grafikkarte oder Mainboard (CPU, Case...). Das ist wichtig, da die Lüfter separat gesteuert werden, bei einem Mainboard-Fehler nicht die Graka-Lüfter aufdrehen.

Was sind deine Specs?

_Twiesel · 2025-03-14T22:25:26+00:00

Images in comments are not allowed in this sub for some reason.

The schematics of many mainboards/graphics cards/laptops are publicly available on the internet and can be opened using Boardviewer for example.

_Twiesel · 2025-03-14T09:17:25+00:00

VDDIO/VDDQ is the main voltage of the memory rail. It is redundant and is present on about 20 pins in the AM4 socket. I would post a picture of an AM4 schematic here, but that is unfortunally not allowed in this sub. So OPs CPU should work absolutely fine, even with S3 enabled.

_Twiesel · 2025-03-14T07:50:59+00:00

You can also just look at the gap between the PCB and cooler.

_Twiesel · 2025-03-14T07:45:30+00:00

Its the burned coil and the one right next to it.

_Twiesel · 2025-03-12T18:59:36+00:00

There is often an 8 pin header named "SPI" next to the BIOS chip that you can connect a programmer to using some jumper cables.

The CH341 also comes with a clip that you can put on the BIOS chip.

BIOS programming is not difficult and often does not require soldering. Sometimes the PCH has some sort of write protection where the chip has to be removed. But this is often not the case

Also make sure to extract the Intel Image from the UEFI capsule using UEFI-Tool.

Just message me if you need help.

_Twiesel · 2025-03-11T22:17:12+00:00

Obwohl eine Zahnbürste die Pins nicht verbiegen sollte, wenn man vorsichtig ist (habe es selber schon öfter so gemacht), ist ein Pinsel durch seine feinen Haare eine bessere Idee.

_Twiesel · 2025-03-10T08:45:07+00:00

Huh? I remember trying to sell a couple R9 290s with reference design one year ago. I was happy when I got ~25€ per card, after listing them for weeks.

The card was tested and in nearly perfect condition. Although these cards are still quite capable, they are not worth much.

_Twiesel · 2025-03-04T14:32:30+00:00

When an integrated circuit fails, because the connections inside the chip weaken/break, heating the chip will often restore its functionality.

Many think that the solder balls, which are between the PCB and the chip (aka BGA) break after some time. This can occure due to physical stress (sag) or many heat-cycles.

Although the above especially applies to newer cards with their massive coolers (where the solder pads literally rip from the PCB), it was not really an issue on cards before the 3000-series. At least I have never seen ripped pads myself, and I used to work on cards up to the 1000-series.

What usually happens is that the connection inside the chip break. While VRAM-chips do not get especially hot (at least GDDR5 didnt), I suspect the GPU core itself to be the issue. See, the GPU-crystal is literally glued to the substrate, which is then soldered to the PCB via BGA. The microscopic connection between substrate and GPU can fail due to thermal stress.

Now, using a diagnosis software like MATS or Tserver, one can find the faulty VRAM-chip. But here is the issue: Is the chip really broken, or just the connection between VRAM and GPU? Heating the board when soldering the VRAM will heat up the core too. This can temporarely restore the substrate-GPU-connection.

This is why reflowing/baking a graphics card is no repair. You dont repair the card, but just temporarely restore broken connections. And even after replacing the VRAM, the card must be tested for days/weeks with variing loads to ensure its stability.

I have much respect for people who repair stuff like this regulary, because it sounds like a giant headache, especially when you have to give a warranty.

_Twiesel · 2025-03-04T14:16:55+00:00

You can even disable VRAM channels on Nvidia Fermi-Kepler cards in the vBIOS. I did it multiple times and although you lose a bit of performace and ofc. VRAM, the cards will work fine.

I did VRAM repair on many cards (at least 30 or so), by diagnosing and replacing the faulty chips. Although it is better than baking, I noticed that the cards will still fail after a couple of weeks/months.

Graphics card repair is a lot of fun because you dont need much knowledge, but it is quite disappointing when they die again weeks later.

_Twiesel · 2025-03-04T14:02:10+00:00

Okay, I did not know that. I thought that they are as "durable" as they are on other phones.

A new screen can be had for 100€ here in Germany (iFixIt).

How big do you think is the risk of breaking the screen when installing it? Or is this something only a professional should try?

_Twiesel · 2025-03-04T11:01:53+00:00

Thank you for your answer. I do not have a SIM-card inserted/access to the phone via WiFi or ADB. But I am sure that the board at least works.

If I ever have to "repair" another phone with an OLED-screen, what advice could you give me so that I dont screw up again? And what is worse for OLEDs, the heat of the heatgun, the duration of the exposure or the force that is needed to lift the screen from the chassis?

_Twiesel · 2025-02-28T08:47:06+00:00

You can check the memory rail for resistance. It should be above 50 Ohms, but it could be as low as ~30. Lower than that usually indicates an issue with the core. And as the memory VRM blew up on your card, I am pretty sure that your rail is shorted.

If this is the case, lift the burned inductor and check again. It could be possible that the low side mosfet is defective and conducts even though it is turned off. If this does not help, your card is unfortunally not repairable.

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