electrum & coldcard watch-only wallet issue (derivation path, maybe)

[vectorx8]

Hello!

I would like some technical help, please.

I use Coldcard with Electrum interface; deposit is made to a watch-only wallet generated some time ago using the extended public key (zpub, since it's Native Segwit) from the original standard wallet (also generated from Coldcard).

Last week, I needed to restore the original standard wallet because I changed my PC, however after generating it from Coldcard and transfering through a microSD to my PC, no balance is shown at Electrum.

I've got back to my old PC, opened the watch-only wallet on Electrum and everything is fine. The balance is still there.

As I created the wallet more than 2 years ago, I don't remember some details. Maybe, (but, just maybe. it's a hypothesis!) it's related to account number (aka derivation path). I don't remember if I created something different from 0 back then. I've tried plenty of different derivation path, but none match the zpub where the balance is shown.

PS.: on Electrum, the watch-only wallet doesn't show the derivation path neither the fingerprint.


Is there anything I could do to identify my wallet again?
Do you guys recommend anything?

Thanks,

[DireWolfM14]

Electrum won't show the master fingerprint for a watch only wallet, as far as I know.  And it wouldn't have the information from the master key to show derivation paths either.  Does your old computer still have the main wallet file?  IIRC, ColdCard adds the fingerprint to the file name when you export it to the mSD.

Do you have the original seed phrase?  The ColdCard will display it, in case you forgot to write it down, which you should have done anyway just in case the ColdCard goes kaput. 

My suspicion is that you included a passphrase to generate your wallet, which is a wise thing to do.  I hope you wrote that down also, or at least remember what it is, if you used one.  Once you log the passphrase into the ColdCard it will show you the master fingerprint, and hopefully you can match it to the filename of the main (not watch-only) wallet.

[nc50lc]

I use Coldcard with Electrum interface; deposit is made to a watch-only wallet generated some time ago using the extended public key (zpub, since it's Native Segwit) from the original standard wallet (also generated from Coldcard).
-snip-
Maybe, (but, just maybe. it's a hypothesis!) it's related to account number (aka derivation path). I don't remember if I created something different from 0 back then. I've tried plenty of different derivation path, but none match the zpub where the balance is shown.

The statement above could mean that you've used the standard legacy derivation path to derive the Native SegWit extended public key.
That's if you mean P2PKH (legacy) when you said it's from the "original standard wallet".
In this case (USB connection), try to select "Legacy" first, copy the derivation path below, then select "Native SegWit", and paste the previously copied derivation path.

Or since that was created with you a zpub from your Coldcard, have you tried to sign transactions created by that watch-only wallet via PSBT export? (guide)
Is it still working? If so, you can simply transfer the wallet file from the old PC to your new PC.
Copy it from/to: [Electrum Datadir Location]/wallets

Questions; have you reset ColdCard? Set a new seed? Passphrase?

[dkbit98]

Is there anything I could do to identify my wallet again?
Do you guys recommend anything?

All you need is to have correct seed words backup in safe place, and you can always restore it in different wallets, but you didn't say what coldcard device and wallet version you are using.
Instead of using Electrum wallet you can try if Sparrow can find your addresses, from my experience this wallet works better when connected with hardware wallets.
And make sure yu didn't use additional passphrase on top of your seed words.

[vectorx8]

Electrum won't show the master fingerprint for a watch only wallet, as far as I know.  And it wouldn't have the information from the master key to show derivation paths either.  Does your old computer still have the main wallet file?  IIRC, ColdCard adds the fingerprint to the file name when you export it to the mSD.

Do you have the original seed phrase?  The ColdCard will display it, in case you forgot to write it down, which you should have done anyway just in case the ColdCard goes kaput. 

My suspicion is that you included a passphrase to generate your wallet, which is a wise thing to do.  I hope you wrote that down also, or at least remember what it is, if you used one.  Once you log the passphrase into the ColdCard it will show you the master fingerprint, and hopefully you can match it to the filename of the main (not watch-only) wallet.

Firstly, thank you for your reply. It's my first time I post here and I see how kind people are.

Just sharing more information that maybe can help us to think about a solution:
 - I do have the seeds + passphrase (so, it's 25 words);
 - in the watch-only wallet, whose file and access I still have, all address are shown as "bc1q...". futhermore, the public master key starts with "zpub...". For these reasons, I conclude the main wallet was generated on Native Segwit, since these patterns are typical of it;
 - I tested a cenario which a new wallet was created, but the account number was different from 0. When exporting to the mSD using any number but the right one, the balance is shown as zero and, besides, everything else is different from the main wallet (like zpub and address). So, the account number does influence what's generated.

I am wondering if there is any other way to find the right account number.
Or, if this issue isn't related to that, since it's a hypothesis, what could I do?

Is plugging the Coldcard to the USB and Electrum the right way?
Or, only writing the seeds into the Electrum restore option?

By the way, doing any of these could in fact resolve the issue, if related to lost account number (or derivation path)?

[vectorx8]

I use Coldcard with Electrum interface; deposit is made to a watch-only wallet generated some time ago using the extended public key (zpub, since it's Native Segwit) from the original standard wallet (also generated from Coldcard).
-snip-
Maybe, (but, just maybe. it's a hypothesis!) it's related to account number (aka derivation path). I don't remember if I created something different from 0 back then. I've tried plenty of different derivation path, but none match the zpub where the balance is shown.

The statement above could mean that you've used the standard legacy derivation path to derive the Native SegWit extended public key.
That's if you mean P2PKH (legacy) when you said it's from the "original standard wallet".
In this case (USB connection), try to select "Legacy" first, copy the derivation path below, then select "Native SegWit", and paste the previously copied derivation path.

Or since that was created with you a zpub from your Coldcard, have you tried to sign transactions created by that watch-only wallet via PSBT export? (guide)
Is it still working? If so, you can simply transfer the wallet file from the old PC to your new PC.
Copy it from/to: [Electrum Datadir Location]/wallets

Questions; have you reset ColdCard? Set a new seed? Passphrase?

Firstly, thank you for your reply. It's my first time I post here and I see how kind people are.

Just sharing more information that maybe can help us to think about a solution:
 - I do have the seeds + passphrase (so, it's 25 words);
 - in the watch-only wallet, whose file and access I still have, all address are shown as "bc1q...". futhermore, the public master key starts with "zpub...". For these reasons, I conclude the main wallet was generated on Native Segwit, since these patterns are typical of it;
 - I tested a cenario which a new wallet was created, but the account number was different from 0. When exporting to the mSD using any number but the right one, the balance is shown as zero and, besides, everything else is different from the main wallet (like zpub and address). So, the account number does influence what's generated.


I tried to sign a transaction on my Coldcard which was previously generated from the watch-only wallet in Electrum. However, it's not possible.
On antoher occasion, which one I had all information known (like seeds, passphrase, account number, ...), I tried the same and, again, I realizaed it's not possible to sign a watch-only transaction. Only the main wallet grants that.

As for your questions:
 - when I mentioned "standard wallet" I meant main wallet. I'm not referring to the Legacy version.
 - I haven't tried to reset the Coldcard. Why should I do that?
 - As mentioned before, I do have the seeds + passphrase. But I haven't tried to write them down into Electrum in order to restore the main wallet.

[vectorx8]

Is there anything I could do to identify my wallet again?
Do you guys recommend anything?

All you need is to have correct seed words backup in safe place, and you can always restore it in different wallets, but you didn't say what coldcard device and wallet version you are using.
Instead of using Electrum wallet you can try if Sparrow can find your addresses, from my experience this wallet works better when connected with hardware wallets.
And make sure yu didn't use additional passphrase on top of your seed words.

Firstly, thank you for your reply. It's my first time I post here and I see how kind people are.

Just sharing more information that maybe can help us to think about a solution:
 - I do have the seeds + passphrase (so, it's 25 words);
 - in the watch-only wallet, whose file and access I still have, all address are shown as "bc1q...". futhermore, the public master key starts with "zpub...". For these reasons, I conclude the main wallet was generated on Native Segwit, since these patterns are typical of it;
 - I tested a cenario which a new wallet was created, but the account number was different from 0. When exporting to the mSD using any number but the right one, the balance is shown as zero and, besides, everything else is different from the main wallet (like zpub and address). So, the account number does influence what's generated.

As for your questions:
 - I am using Coldcard Mk3;
 - I am using Electrum 4.5.5 (lastest version, by now);
 - I've never used Sparrow before, but I'm open to that in order to try different options;
 - As mentioned by me before, I have "seeds + passphrase"; So, it's 25 words.

Anything else you recommend?
I believe it's related to derivation path (aka account number in Coldcard), but I am open to more ideas, please.

[nc50lc]

As for your questions:
 - when I mentioned "standard wallet" I meant main wallet. I'm not referring to the Legacy version.
 - I haven't tried to reset the Coldcard. Why should I do that?
 - As mentioned before, I do have the seeds + passphrase. But I haven't tried to write them down into Electrum in order to restore the main wallet.

Those questions are to identify if you've set a new seed phrase or passphrase to Coldcard.
Based from the answers, it seems you've been using the same setup.

I tried to sign a transaction on my Coldcard which was previously generated from the watch-only wallet in Electrum. However, it's not possible.

Have you ticked "For hardware device; inclide xpubs" when you exported (Save to file) the PSBT from the watch-only to ColdCard via SD Card?
screenshot:


Just to be sure, that wasn't created from an exported "skeleton wallet" but by directly importing the zpub from an already existing Electrum wallet created by ColdCard?
If so, it's missing some of the information in its keystores in comparison to a normal Electrum wallet created from a skeleton ColdCard wallet
And that could be the reason why the Cold Storage signing method wont work.