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[sheddyian]

Well at least the Kitty-shop has received a financial donation from yourself. You could complete that donation circle by re-donating the two PSUs that you have only just purchased! 

I may have cut the plug off the 12 volt one just before realising it was AC....

I'll put it in the shed.  It might be useful for something.

Ian

[sheddyian]

Look what I just found in my shed, that I'd forgotten all about :



Just to insult me a bit more, it was me who wired that DC power plug onto it as a temporary measure some time ago.  A DC power plug that is centre positive AND FITS THE BT MODEM!

All this time searching and I had the very thing in my shed all along.

It was originally a power supply for a 12 volt powered Peltier Junction dehumidifier I'd got from a junk shop, that did an admirable job of drying my shed out when the roof had been leaking.  But I found that the PSU was a bit under-rated, and ran very hot powering the dehumidifier, so instead I ran it from a car battery with a mains battery charger topping it up all the time as it was running.

I'd later bodged the wires on the PSU so that it could run an old LCD computer monitor that I wanted to test, that wanted a 12volt DC power supply, not mains.

And the plug for that old monitor happens to be the same size one I need for the BT modem/router.

Still, at least I've got something now, and it works (meter says it's outputting 12.4 volt with no load).

Off to try it out ! 

Ian

[roseway]

Off to try it out ! 

I hope it doesn't do what the little picture suggests.

[sheddyian]

I might as well have set my hair on fire today, I'm getting old and senile I think.

Forgetting that I had a power supply THAT I'D PUT THE RIGHT PLUG ON

Then :

Having opened up the BT Homehub last week, I've now lost the power button.

Connected it all up, it wants me to change from the default (but unique) password.  But I don't know what that is, because the little plastic tab with passwords & keys on wasn't there when I bought it.

Decide to do factory reset, but realise I need MAC address & serial number from the bottom of the foot that the modem sits on.  Spend several hours looking for this, as I thought I'd removed it.  I hadn't, it was attached to the half-opened modem case all along.

In the process of looking for the foot that wasn't missing, I FOUND MY NEW RASPBERRY PI that I thought was lost in the post.  It was attached with an elastic band to another parcel that arrived a week ago, which I hadn't opened yet as I knew what was in it (a mains lead).  I hadn't spotted that the one parcel was actually two, elastic banded together by the postman.

In fact, it was THREE parcels as the memory I'd ordered from China a month ago (but wasn't really expecting just yet) was also taped to it all.

I'm going for a cup of tea and a lie down.  I daren't do anything technical today, I'll end up setting fire to something or formatting the wrong disk.

Ian

[roseway]

I prescribe cocoa and an early night.

[burakkucat]

I'm going for a cup of tea and a lie down.  I daren't do anything technical today, I'll end up setting fire to something or formatting the wrong disk.

Look on the bright side. You can blame it all on the Sheddy gremlins. 

[sheddyian]

Well, I may have discovered the reason why this BT Home Hub 3 was on sale for 50p in a cat's charity shop...

It starts up ok, get flashing lights which go steady, and then I can see it's web configuration screen.  Was studying that, when the PC suddenly reported that a network cable was unplugged.  The lights on the hub had changed colour.  It then proceeded to reboot, then go steady, pc detected new device, then lost it and the hub rebooted again.

When I unplugged it it was incredibly hot.  It had been powered up for maybe 15 minutes max.

My improvised power supply is outputting 12.3 volts, so I don't think it's my fault it's overheating.

Who'd have thought a 50p modem from a cat's charity shop would cause me so much grief, eh? 

Ian

[asbokid]

Don't crush it under foot just yet!    Somewhere on the board may be points for obtaining UART and/or JTAG connections.  A case of (very) patient probing, if you've got the patience!

cheers, a

[sheddyian]

I'm not sure I've got the technical expertise for locating UART or JTAG connections!

Also, what would that gain me?

The modem starts working, then crashes after a quite short time (presumably because it's running very hot.

Is that not likely to be a hardware failure rather than firmware (I'm assuming you're thinking I could reflash the firmware using the JTAG?)

Ian

[asbokid]

I'm not sure I've got the technical expertise for locating UART or JTAG connections!

Yeah, course you have :-)   

Also, what would that gain me?

It's probably a firmware fault.  A pushed f/w upgrade that failed.  Those are the same symptoms - repeated rebooting.  The device has got some sort of checksum detection routine that forces a reboot if the f/w checksum fails.  Hence the re-boot cycling.

The modem starts working, then crashes after a quite short time (presumably because it's running very hot.

The BCM6361 does run very hot.  There's quite a hefty heatsink on it. Is it excessively hot in areas of the board other than the CPU?  The power regulation is that hot?

Is that not likely to be a hardware failure rather than firmware (I'm assuming you're thinking I could reflash the firmware using the JTAG?)

Or even flash it by UART.  That's got a different bootloader to the more usual Broadcom CFE bootloader, iirc, but it's probably got a flash write function in it.  First guess though would be a f/w fault.   The device probably wouldn't have got to the point of re-booting and twiddling its LEDs if it were a hardware fault.

The NAND is worth a quid or two, if you can get it off intact!

cheers, a

[sheddyian]

Ah, but the modem does start up.

The PC saw it, and it's DHCP gave the PC an ip address.  I was able to see the configuration screens, look at the help etc via the web interface.  (The PC was ONLY connected to the homehub 3 - via a single lan cable, I wasn't getting confused with another network device )

It was running for maybe 15 minutes before it started reboot cycling.

Which is why I concluded a hardware fault.

Several areas of the board were getting very hot - somehwere near the DC power socket, the chip on the back of the board was very hot, and something under the metal screening can (doesn't look like a heatsink) was also very hot.  It smelt hot too.

The label definitely says 12 volts, and I was definitely giving it 12 volts 

I can understand a failed firmware update causing the symptoms you describe - repeated power cycling.  But running seemingly ok for a while (albeit only 15 minutes) and then starting to power cycle?

Ian

[GigabitEthernet]

Have you tried turning it on and and leaving it and then seeing if the same behaviour occurs? I do recall there being a bug with the Home Hub 3 where it would reboot when one used the web interface.

[asbokid]

I can understand a failed firmware update causing the symptoms you describe - repeated power cycling.  But running seemingly ok for a while (albeit only 15 minutes) and then starting to power cycle?

Sorr,y, that does sound bad :-(  oh well.  Something wrong with the power regulation circuit?

cheers, a

[sheddyian]

arobertson545: I'll try powering it up and not accessing it, but the heat & subsequent failure leads me to think it's just faulty.

asbokid: That seems possible, since it's several things that seem to be getting unreasonably hot.

Ah well, it was 50p.  I'll take it to the recycle depot!

Was hoping to use the USB as part of a NAS device, especially since it's got a gigabit ethernet port on it.  Will keep a look out for more of them

Ian

[JohnJBurness]

In my grotto, I have both a BT HH3.0B and a BT BH3.0. I have been led to believe that the latter is just a BT HH3.0A with different firmware . . .

Looking at the PSU of the BT BH3.0, I see it is marked as follows --

BT Switching Power Supply
Model No: S012NB1200100
P/N: 253371437
Input: 230V~50Hz 300mA
Output: 12.0V==1000mA
For use with BT Home Hub 3.0 Type A

I can confirm that the centre pin is the positive connection on the Hub.

Measuring the PSU plug, to the best of my ability, I make its dimensions to be 12 x 5 x 2.1 mm. (L x D_outer x D_inner)

Can I just add that the PSU Plug, for a Type A, is different to that used for a Type B!

My HH was not working very well & BT sent me a replacement - the original was a Type A & the replacement is a Type B.