Thomson Sky-HD (and Sky+) PSU failure

admin · Posted: Tue May 27, 2008 3:03 pm Post subject:

Some of the electrolytics - especially the 1200µF - are very highly stressed by being subjected to fast risetime, high energy pulses. To cope with this without overheating, they have to have a high current rating, which requires a very low "Effective Series Resistance" (ESR). I can't put it more simply because it's quite a difficult concept.

The only capacitors we could find, which were good enough (for our 3 year guarantee), were available only from America. Had the Maplin ones been good enough, we'd have bought those and saved ourselves a lot of hassle!

In the case of electrolytic capacitors, they all have a limited lifespan expressed in hours at a specific temperature. So every fix is "temporary". In our case "temporary" means at least 3 years. If you are happy to replace the capacitors every 6 months or so then use whatever you can get hold of.

By the way, the kits contain exactly the same capacitors as the Rebuilt PSUs. The only reason we don't specifically offer a 3 year guarantee on the kit capacitors is that people could fit them the wrong way round and damage them, then claim they were faulty.

andyt · Newbie Joined: 27 May 2008 Posts: 6

OK, thanks for the advice. I've decided I should order the kit and fit the bits from there. It was more that I wanted to get it sorted ASAP (since the wife gets tetchy when she can't watch Desperate Housewives..), rather than wait for the kit!

Oh, and is it my imagination or has the kit gone up by £1 since yesterday?!
Wink

admin · Posted: Wed May 28, 2008 4:22 pm Post subject:

Yes, cost of ordering parts from the USA. Cost of employing another repairer. We held it down as long as we could. But let me know your order number.

andyt · Newbie Joined: 27 May 2008 Posts: 6

(number hidden), but it's OK, I wasn't demanding a discount, I'm just glad to know my memory is OK and I'm not going mad!

admin · Posted: Wed May 28, 2008 5:01 pm Post subject:

Sorted, although you just missed the post. Your kit will go out tomorrow.

alanforster · Newbie Joined: 28 May 2008 Posts: 1

Firstly, thanks for the kit I received today to fix my PSU.. very quick service!

I've installed the capacitors provided and am glad to see its solved the blocking channels. However I must have screwed something up as the fan is now blowing inconsistently (speeding up then slowing down again every second or two). Any suggestions as to where to start if it's a problem you've encountered?

Any help is much appreciated.

Thanks

Alan

admin · Posted: Wed May 28, 2008 6:29 pm Post subject:

Sorry, no idea.

You could try asking Michael who repairs Sky+ digiboxes and the occasional Sky-HD:
http://www.DigifixLtd.co.uk

admin · Posted: Wed May 28, 2008 11:21 pm Post subject:

16 more PSUs were shipped out today.

admin · Posted: Wed May 28, 2008 11:33 pm Post subject:

Has anyone with a rebuilt power supply suffered the "back-to-back" failed recording symptom which is described here?
http://www.avforums.com/forums/showpost.php?p=7097800&postcount=18

admin · Posted: Fri May 30, 2008 11:02 am Post subject:

RUBBER PINS
We finally managed to get another batch! Apologies for the delay but there's only one supplier and we have to place our order several weeks in advance. The trick is in predicting when stocks will get low and demand has been much higher than we expected.

sunil1234 · Newbie Joined: 09 Mar 2008 Posts: 26

Just an update on the second replacement rebuilt PSU I only got round to fitting last week.

Everything seemed OK at first (just like the first rebuilt PSU) in that no out of standby issues/ failed recordings or blocking on "most" of the channels that I used to get before with the original PSU. However, without fail every time I record anything HD (and only one HD programme recording at a time) then I always get a small bit of blocking and sound drop out early on and then no more after that for the rest of the hour long programme. This was the same with the first rebuilt PSU so a replacement hopefully means it isn't the PSU causing it.

Its really weird but I don't get any other issue than just this one on HD channels. I am not sure if the same thing would happen if i watched the programme live as I am usally in bed when its on and its happened on all 3 instances of it since the new PSU was fitted (Lost on Sky one HD). When I recorded disocvery HD and nat geo HD at the same time when fitting the second rebuilt PSU it didn't show this problem so I am not sure why it might have arised on skyone HD since?

As this is my second rebuilt PSU, I don't know what else to do although it is bloody annoying!

I still get the problem that if i go to signal strength meter, the tuner 2 can show fine or can show nothing for a few seconds and then appear. Is this a fault or just software bug. The bars are always there for tuner 1?

Also if I select BBC1 really quick from the sky menu then I get "No Satellite Signal .." but selecting it slowly will get the channel back. don't seem to have this problem on doing the same with many other channels?
- have had this problem before the PSU started failing. It doesn't do this on my Amstrad sky+ or pace sky+ boxes running off the same dish?

Any advice much appreciated

TIA

S

admin · Posted: Fri May 30, 2008 4:25 pm Post subject:

There were several reports about "Lost" getting lost this week on the digitalspy forums. I think the chances of its being caused by the PSU are slim. More likely there's a firmware bug that affects only specific recordings.
http://www.digitalspy.co.uk/forums/showthread.php?t=803166

andyt · Newbie Joined: 27 May 2008 Posts: 6

admin · Posted: Sun Jun 01, 2008 5:16 pm Post subject:

I confess that I haven't got one of my own so I haven't had the opportunity to stick my fingers on a live heatsink (don't try this at home, kids!)

But it's not uncommon for a heatsink to "boil spit". The heatsink gets really hot if the largest capacitor (400 volts) dies. As yours will be new, it should be fine.