Fauty Wiser HubR

[sparkler13]

My Wiser HubR developed a fault of constantly resetting /rebooing every 10 minutes. Been onto tech support for some weeks without any progress apart from normal basic questions. I sent videos, they apparently logged into it and couldnt see any problems.

After lots of fault finding I found that with 3 TVR's connected it was stable, adding a 4th tipped it over the edge and the HubR started resetting again. It was always exactly 10 minutes between reboots. I presumed the HubR requested info from the TRV's every 10 minutes suspecting a memory corruption or similar.

I went out and purchased a new one and now all is working well, everything works so definately a fault had developed after a few years of usage. Still waiting for tech support to come back to me after 5 days silence and ask me some more irrelavant questions as they have gone quiet.

I dismantled the old and took some pictures of the PCB both sides. Maybe someone is interested in what it looks like inside

 

[CBW]

Sounds like a pain in the arse. Maybe Drayton don’t know the answer?

 

[DetlefSchmitz]

I'd be inclined to try replacing the electrolytic capacitor (middle right of pic 2). Symptoms sound about right.

 

[sparkler13]

I'd be inclined to try replacing the electrolytic capacitor (middle right of pic 2). Symptoms sound about right.

Thanks for the advice, I might give it a go. I know its a 1000uF capacitor but how do I know what voltage rating?

 

[DetlefSchmitz]

It really should say on it. Maybe round the back?

 

[RandomGrinch]

Thanks for the advice, I might give it a go. I know its a 1000uF capacitor but how do I know what voltage rating?

I believe the LNK305CN is a 12V AC/DC converter, so a cap of at least 16V may be ok, as above check for markings on the other side of the cap.

...it's interesting that there is some corrosion on the bottom of the PCB in the capacitors location. A clean up with some IPA there, wouldn't hurt! Nor would changing the backup battery

 

[sparkler13]

I believe the LNK305CN is a 12V AC/DC converter, so a cap of at least 16V may be ok, as above check for markings on the other side of the cap.

...it's interesting that there is some corrosion on the bottom of the PCB in the capacitors location. A clean up with some IPA there, wouldn't hurt! Nor would changing the backup battery

Thanks, Ive checked and the only writing is 102. Is it worth me checking underneath the skin?
Its not easy to get hold of components on the high street any more so would appreciate any advice what component to get before I order online. I also noticed the corrosion so will clean it up if I replace the capacitor.

 

[DetlefSchmitz]

You could also put a dc voltmeter across the one on the new board, and then add a bit.

 

[RandomGrinch]

Thanks, Ive checked and the only writing is 102. Is it worth me checking underneath the skin?

Yes, take the heat shrink off, there may possibly be some writing underneath.

Its not easy to get hold of components on the high street any more so would appreciate any advice what component to get before I order online.

The size of the capacitor will also give an indication of the voltage rating, for instance, this 16V 1000uF cap has a diameter of 10mm and is 16mm high...

https://cpc.farnell.com/multicomp/mcgpr16v108m10x16/capacitor-85c-16v-1000uf/dp/CA04742

I personally order from CPC or Rapid; as long as you want a few items, you can avoid silly postage costs and minimum order quantities. For one off small purchases, eBay or Amazon are ok.

...and of course, mind the polarity!

 

[sparkler13]

Yes, take the heat shrink off, there may possibly be some writing underneath.


The size of the capacitor will also give an indication of the voltage rating, for instance, this 16V 1000uF cap has a diameter of 10mm and is 16mm high...

https://cpc.farnell.com/multicomp/mcgpr16v108m10x16/capacitor-85c-16v-1000uf/dp/CA04742

I personally order from CPC or Rapid; as long as you want a few items, you can avoid silly postage costs and minimum order quantities. For one off small purchases, eBay or Amazon are ok.

...and of course, mind the polarity!

I'd say it was 8mm diameter and 10 mm in height. There isnt anything under the heat shrink. I'll have a look to order overteh weekend.
Thanks for your help.

 

[Gasguru]

That component is a 1mH choke....I suggest you chuck the lot in the bin. Most of that board operates at lethal voltage and given the comments so far, any attempt at repair would be ill advised.

 

[RandomGrinch]

That component is a 1mH choke....

Thank you, yes, apologies to the OP, I didn't look closely enough.
But...

Most of that board operates at lethal voltage

That is something I would disagree with!

Although, there isn't now much scope for repair.

 

[mcprinter]

Thank you, yes, apologies to the OP, I didn't look closely enough.
But...

That is something I would disagree with!

Although, there isn't now much scope for repair.

To be fair to you, 102 is also the type of numbering used for caps. Normally small ceramics/poly.

240V on the Hub so potentially a little risky.
I have had the odd mains and undischarged capacitor tickle over the years

 

[DetlefSchmitz]

Apologies from me too. I should have realised my mistake on hearing about the absence of voltage marking. It's just a good rule of thumb to look for electrolytic capacitors as in general they only have a lifetime of 2000 hours.

 

[Gasguru]

That's the rating at high temperatures but you design accordingly. Electrolytics can last a 100,000 hours and more.