Friday, August 8, 2025

More on Watch Demagnetizers - Strength Matters.

After a recent trip, I found my new Hanhart was gaining about 40 seconds a day. I checked it with a magnometer app and a compass and it had become magnetized.

I did have a couple cheap plastic "demagnetizers" and I have used them successfully on my Omega (see my previous post).
But I cannot get them to work on the Hanhart. Maybe the Hanhart is too well shielded, as it is specified and marketed as "antimagnetic".

So I brought the watch to two watchmakers... both didn't want to touch it because it was under warranty. That was strange to me and I essentially begged them to put it on their demagnetizers and they refused. Maybe they just didn't want any liability for an attempted repair, especially knowing the watch was still under warranty.

So I went to eBay.
First I bought a nice vintage South Bend unit:



Testing the South Bend with a small screwdriver, it was CLEARLY more powerful than the cheap chinese units I had tried. So I put the Hanhart through it many times... and sadly it didn't help.

Somehow, I remained convinced the watch was magnetized, as it's symptoms perfectly matched that. No beat error, good amplitude, but 40+ seconds a day too fast. I still believed the "antimagnetic" shielding of the watch was just making it harder to demagnetize.



A bit of research showed that push-button "instant" demagnetizers are significantly more powerful that the others. So I searched for and found an old Elimag that was claimed to still be working:



The Elimag is claimed to be very powerful, as it uses a voltage quadrupler circuit, meaning it charges to more than 400 Volts. I pulled the crown out (stopping the watch) and put the Hanhart on the Elimag face down and pushed the button. For the heck of it, I did it again, and then on the side crown up and crown down.

And then tested the watch on my timegrapher.... FIXED! +3s/d face up! Yay!
Watch is working perfectly.



Beware of magnetism. ;-)

Tuesday, April 1, 2025

Watch Demagnetizer Testing and Demonstration (also works with small tools)

 My newly serviced mechanical watch suddenly gained half a minute overnight. So I checked it and found the timegrapher showed more than +20 seconds a day.

A quick google said the likely cause was magnetism and a compass did show it was slightly magnetized.

So I bought two cheap watch demagnetizers on Amazon. A blue "Tui Ci Qi" unit for about US$13 and a white "HUAXING" unit like a mini MRI machine for about US$20.


I put both of these devices on a power meter, and found the blue one used about 7.6W and the while one about 23.3W. And then I played with both, magnetizing and demagnetizing a small screwdriver. In my opinion the white unit worked better, but it could be the technique. 

For the blue unit, most recommend putting the watch/tool on the pad, turning the unit on and then slowly lifting the watch/tool up and away from the pad for more than 24" (60cm) before turning the unit off. But some recommend rubbing the watch/tool back and forth and around on the pad. I tried both with my magnetized screwdriver with variable results.

For the white unit, most recommend putting the watch/tool in the unit's hole, turning the unit on and then pulling the watch/tool out and away from the unit for more than 24" (60cm) before turning the unit off. However, some people recommend passing the watch completely through the unit from one side to the other.

For either unit, multiple passes could be used to possibly improve the results. I found the white unit consistently demagnetized my screwdriver in one pass.

I made a video showing a demonstration of the white unit:

I did disassemble both units, and both are VERY crudely made. I highly recommend only plugging these in when using them and unplugging them when done! Also, the manufacturers recommend only uses them for a very short time before letting them cool off. The white unit says to use it for 1 minute maximum.

Interior photos for those that are curious.



Oh, after a pass through the white demagnetizer the performance of my watch is restored. ;-)

Friday, September 20, 2024

The 12VHPWR fiasco - or: Choosing a replacement adapter cable for your GPU.

An Nvidia 12VHPWR adapter cable with a chip in it.

The 12VHPWR fiasco… or: choosing a replacement adapter cable for your GPU.
This issue has been around for a long time, but I only just got an RTX 40 series card and so it is all new to me. Please let me know if I have something wrong below…

I received my new RTX 40 series GPU and it came with an Nvidia branded 3-into-1 12VHPWR adapter cable for the power supply. Sadly, my Corsair power supply only came with 2 PCIe power cables, so I needed an additional PCIe cable to make the Nvidia adapter work properly. But if I purchased that cable, I’d end up with an octopus like mess of 4 cables connected together just to get power to my GPU! Another option would be to "daisy chain" one of my existing PCIe cables, like this:
An ugly mess that isn't a good idea.

Clearly, I should just get one cable to replace this messy bundle.

But!...
  1. Of course, the power supplies are not all the same... some use different proprietary pinouts! This is why many recommend using the Nvidia adapter provided with the GPU with the cables that came with the PSU, and I suspect the chip in the adapter cable helps check things too.
  2. Wait… there is a chip in the Nvidia octopus adapter cable that comes with the GPU?! Apparently, the Nvidia 3-into-1 adapter cable that comes with the GPU actually has a chip in it that tells the GPU that all three ends at the PSU are plugged in and supplying the proper voltage etc. But the aftermarket cables do not have that chip and I suspect just hard-wire the sense lines. I read that this is fine, as long as you actually properly plug the adapter into a properly spec'd supply. Also, note the Nvidia adapter cable seems to connect all the positive wires together, and same for the ground. The aftermarket cables only seem to short adjacent PCI2e wires together at the 12 pin GPU connector.
  3. I had remembered there was a connector problem when these RTX 40 series cards first came out: connectors at the GPU were melting! People were not plugging in the connectors all the way, or they were bent hard near the GPU and that was pulling them out or weakening the connections. Also, original cables were soldered to the connectors, a potentially bad practice for power cables. So you want to get a quality cable, with crimped connections. And don’t stress the cable by bending it harshly at the connectors.
  4. You can now get cables with a 90 degree (right angle) connector at the GPU, so the cable doesn’t have to bend hard, an issue in smaller cases like mine. The right angle can bend up toward the backing plate or down toward the cooling fins. Note that if you want a right angle (90 degree) cable you have to make sure your connector on the GPU is not recessed and decide if you want the right angle to bend up toward the backing plate or down toward the cooling fins. Some GPUs may only fit a cable that goes one way, bent up or down. The cable manufacturers seem to call these “A” or “B” variant/type cables. Note that if you choose the bend so that it goes over the latch (B), it may be very hard to remove the connector from the GPU because the connector and cables will be in the way. Choose carefully.
  5. You also need to decide if you need a 2-into-1, 3-into-1 or 4-into-1 cable. This is determined by the power requirements for your GPU. The manufacturer CableMod claims that a 2-into-1 cable is enough to provide a full 600W, but there is little reason to use less than a 3-into-1 cable if you need full power*. 
In summary: So to order a replacement cable, if you need to decide:
  • Can you get one that matches the specific connectors and wiring on your power supply?
  • Are you are OK with using a cable without a chip?
  • Do want a right angle (90 degree) connector on the GPU end of the cable, and if you do, what way should it bend and will it fit?
  • Do you need a 2-to-1, 3-to-1 or 4-to-1 cable?
top: ugly assembly of Nvidia adapter connected to 2 Corsair PCIe cables.
bottom: aftermarket 3-into-1 12VHPWR cable with 90 deg connector.

What a fiasco.

So... I ended up buying 2 cables, one manufactured by CableMod and one made by JOYJOM. They both worked and seemed wired adequately. However, they were wired differently. In the picture below you can see that at the PSU end, the JOYJOM cable is missing 6 connectors and the CableMod is missing 2 connectors. I haven't completely researched what is going on with this, but I suspect both are OK. But again, pick carefully!

I posted on Reddit with the above pic and a CableMod representative replied:

Finally, here is the CableMod cable installed. I chose an "A" version so that the GPU end the clip is exposed and it can easily be detached. In my case, the cable is plenty long enough to come out upward around the GPU card backing plate and then back down behind the GPU to the PSU.

Epilogue: Of course, there is a new power supply cable standard that just came out… don’t be surprised if the next generation of GPUs use a new connector called the “12V-2x6” connector. Supposedly this new connector will be backwards compatible with the 12VHPWR one.

*From the CableMod web site: 
DON’T PCI-E PORTS ONLY PROVIDE UP TO 150W PER PORT? HOW IS IT THAT A 3 X 8-PIN (OR 2 X 8-PIN FOR THAT MATTER) CABLE CAN BE SUFFICIENT TO POWER GPUS THAT REQUIRE UP TO 600W AT PEAK? In truth, an 8-pin PCI-e port on modern PSUs can supply over 300W of power each (up to 342W, depending on model). Thus, two 8-pin PCI-e ports are more than enough to provide the required 600W. We provide both 3 x 8-pin and 4 x 8-pin versions of this cable for extra redundancy. **Please note that all 8 Pin PCI-e plugs need to be plugged in for the cable to function properly. If you order a 2 x 8-pin, 3 x 8-Pin, or 4 x 8-Pin to 16-Pin, make sure that all of the 8-pin connectors are connected correctly to your PSU.

        source: https://cablemod.com/support/#12vhpwr-pcie-gen-5-atx-3-0 

Steve and the team from Gamers Nexus just did a huge report on these cables, adapters and connectors. Check it out here: 12VHPWR is a Dumpster Fire | Investigation into Contradicting Specs & Corner Cutting

After watching the Gamers Nexus video, I'll add these tips:

  1. Make sure you have a large enough power supply
  2. Use the cables that came with your quality supply and the Nvidia branded 3 to 1 adapter cable
  3. Do not bend the cables near the connector. If you have a narrow case or other factors that make the GPU power connection a tight fit, get a right angle adapter cable from a quality manufacturer.
  4. Make sure the cables are fully seated and do not have tension on them.