AirPort Time Capsule rebooting itself every time it disconnect from power

Exactly what model TC is it.. just say tower for the latest AC model..

Otherwise get the A1xxx number from the base.. e.g. A1409 for Gen4.. A1355 for Gen3.. I really hope it is no earlier than that.

You really should not disconnect the TC from power.. that will not make it last longer and it can mess up settings.

I presume it is working just for backup.. so tell me how it is connected into the network and how you expect to use it.

Do use a static IP on the TC itself and set DCHP reservations in the main router as well if possible.

Also setting correct domain can help.. this is assuming the TC is not actually faulty.

When you turn it on does the front LED go green??

What device are you configuring it on.. i.e. iOS device.. PC with windows or Mac with what OS??

Ok.. A1302 suffers from the old power supply problem.. it is amazing that it works at all.

The A1302 should be replaced.. just pull the hard drive out of it and buy a USB enclosure and you can plug it into USB of the newer A1355.

You could try repairing the A1302 or if you have an Apple repair store somewhere around you ask them to replace the power supply.. but I think it would be a waste of money.

https://sites.google.com/site/lapastenague/a-deconstruction-of-routers-and-modems/apple-time-capsule-repair

A1355 is Gen3. Much much better design.. it is full revision of the original design which is same from Gen1 (A1254) and Gen2 (A1302) which use identical main boards but different wireless cards.

How are your DIY soldering skills?

There are full details of how to repair the existing power supply on the reference I gave you. My preference now is to replace the internal power supply with external 12v DC supply and a 12v-5v module inside the TC to supply the 3A or so required for the main board and hard disk.

Even easier if you remove the hard disk completely because then it only needs 5v supply.. all the info and pinouts are there on the website.

You can order a replacement power supply. Tons on eBay.. just type Time Capsule power supply into the search.

They all come from China and most will be refurbished but just as bad as the original. I am not sure what you are paying for them in Israel but most places in the world I would just order another Gen3 or Gen4. They are faster, run cooler and wireless performance is much better. And apple used a different power supply in the later ones.. far superior design. You cannot buy them second hand to use in earlier models unfortunately.

Or buy the Gen4 or Gen5 Airport Extreme which are much better than the Time Capsule in terms of lifespan. Since they use external power supply they don't overheat internally as the TC are renowned for doing.

is there another way to prevent it from disconnecting permanently every time the power is off?

Just use UPS. All network equipment should be on UPS when you have poor power reliability.

Even better use DC .. I have instructions for DIY DC UPS run from SLA battery. (Nowadays you could use Lithium but much harder to charge).

https://sites.google.com/site/lapastenague/diy-ups-dc-controller

This was designed to work specifically with a Time Capsule in situation of bad power where long periods need to be sustained on battery power alone.

Be careful because 12v into the hard drive is very accurate.. you should not exceed 13.2v.. (12v for hard drive must be within+10% and -5%) most SLA batteries are set to 14v and this is really too high for hard disk.. although it might be ok with some older drives.. you are risking it. I did use 13.5v for a while and accepted the risk.. it was OK. But note that a spike would have easily killed the drive and you have no allowance for any overhead.

A different but better way to fix things would be to buy a 1 or 2TB laptop SATA drive and plug that into the TC in place of the 3.5" desktop type drive.. the smaller drives use 5v only and with the board being 5v as well you only need a single 5v external power supply or even better use a 5A 5v module inside the TC so you can supply it with any DC voltage from 9-24v.. and you can then use a float charge SLA battery without any fears of things going wrong.

Btw how bad is it if I'll pull the plug from the new A1355 about every three days?

Remember your NEW A1355 is at least 10years and up to 12years old. Your A1302 is 12-14years old.

When you pull power make sure the hard disk in the TC is not spinning.. just hold it for a few seconds and if you feel vibration wait until it stops.

You will stress it a bit ... obviously just the heating and cooling is not good for electronic equipment. However it is unlikely to cause any great harm. Power on is hard on the power supply though.. so remember that.. and replacements of the original Gen3 supply are very rare.. you would be forced to use DC external supply as replacement.

Do you have any ideas on how to use the A1302 in the most effective way there is? I mean, it is quite a remarkable device, and it still has working parts. I don't like storing old devices just because they are old, and not because they can't function. This one still can, even after 12-14 years :)

Old computers and electronic devices are designed for a certain lifespan.. beyond that.. ewaste. Sorry but even I would not run a TC as old as the A1302. I am happy to keep a Gen3 or Gen4 going just for backup but it is marginal in terms of power usage.

None of the parts are of value. Even as working item it is worth only a few dollars.

They are inefficient cf modern products, poor wifi and produce far too much heat.

Do you think it will be worth it in the future as a vintage product?

No.. it is a network device.. not like an AppleII which has some historical value.

And what do you think causing this problem, that every time it disconnecting from power, it losses all connectivity options and the backups are there but are not accessible?

Really hard to say but failure of the ROM is a possible problem.. maybe the battery would be simple thing to check.. but I am yet to find one out of spec.

a wifi-chip problem

Maybe but that cannot be fixed. Mostly faults on the board cannot be fixed.

Maybe there is a cheap way to make it a remote-backup device

Unreliable backup is useless.

You learned a hard lesson.. don't buy old products for high prices.

To get into the fault troubleshooting is too hard without getting SSH access to the TC.

The first part of this discussion on changing country has links to opening SSH.

https://sites.google.com/site/lapastenague/a-deconstruction-of-routers-and-modems/apple-time-capsule-repair/change-country-on-airport-router

But I can assure you finding a fault and fixing it are two different things. The value of the item vs the cost of repair must be balanced. A faulty chip can only be removed with specialised equipment that costs $thousands. And getting access to the same chip is near impossible so you have to buy another good TC to remove the chip to fix your faulty one.

The only viable checks are voltages.. I have given some details on how to measure all the different power supplies on the TC board. There is a fair bit of detail here.. but from the next model.

https://sites.google.com/site/lapastenague/a-deconstruction-of-routers-and-modems/apple-time-capsule-repair/new-issue-with-a1355-gen-3-tc

Fixes depend on the fault but I have done various things.. in the end.. all of this is just for fun and is not seriously going to put the TC back into operation. But you will learn heaps.