Dead Vu+Duo repair guide

[ajh1949]

Hi,
My box is stuck on starting, however, when I removed the cover a capacitor on what I assume is the power board, has obviously blown as the top was off it! This is marked as C17 on the board. There is also signs of leakage from the large capacitor on the same board marked C1.
Should I try replacing these capacitors?
Thanks
ajh1949

 

[zenith]

hi all not sure what my problem is?
box is original vu duo had for 4 years and has vix 4.2.001 also tried with later vix 3 image same thing happens.
started a week ago where vix sign would come up and box would`nt respond to remote had to restar same again after twenty mins?
i have changed capacitor c807 last year when got red light and fixed my problem until now.
changed that again when seemed same problem doesn`nt have red light.no change so changed c814 and c850 with 220uf 35v all 3 still same problem.box takes time for problem to start and gradually gets sluggish and vix sign coming up.
did notice that one of the capacitors on psu was showing slight bulging not burst?
could this be my problem?
any help on this as always much appreciated

 

[adm]

hi all not sure what my problem is?
box is original vu duo had for 4 years and has vix 4.2.001 also tried with later vix 3 image same thing happens.
started a week ago where vix sign would come up and box would`nt respond to remote had to restar same again after twenty mins?
i have changed capacitor c807 last year when got red light and fixed my problem until now.
changed that again when seemed same problem doesn`nt have red light.no change so changed c814 and c850 with 220uf 35v all 3 still same problem.box takes time for problem to start and gradually gets sluggish and vix sign coming up.
did notice that one of the capacitors on psu was showing slight bulging not burst?
could this be my problem?
any help on this as always much appreciated

Often a faulty electrolytic capacitor doesn't show any physical sign of failure but if you have one that is bulging then consider it to be dead.

 

[adm]

Hi,
My box is stuck on starting, however, when I removed the cover a capacitor on what I assume is the power board, has obviously blown as the top was off it! This is marked as C17 on the board. There is also signs of leakage from the large capacitor on the same board marked C1.
Should I try replacing these capacitors?
Thanks
ajh1949

How are you identifying that the capacitor is leaking? In many PSUs some components are glued to larger components or the board to make the circuit more resilient to vibration (during shipping). The blob of glue is often mistaken for something that has been expelled from a capacitor.

Also be aware that a very large capacitor close to the mains input is likely to have 300+V across it. This can kill! Switch the box off at the mains plug and leave for at least 5 minutes before messing around with this capacitor.

 

[Tmc007]

hi i have a vu+ solo 2 with the same problem could this be the same problem with mine

 

[franta]

hello guys,
i seams to have a different issue: my receiver seams to go automatically to deep standby or at least this is my impression
i have the receiver since 2010 and 2 years ago i had changed the capacitor. all went ok until 3 month ago when the power source went down , I had change the 2 1500mF capacitors in the middle of the board and all was ok. i had replace in the same shot all 3 capacitors on the motherboard (one was replaced 2 years ago) to be sure...

a few days ago in the morning i find my receiver with red light, but the receiver is answering to he remote and when i pres power is starting , then is telling vu duo and after a few second the red light comes again.
i use one of the latest vix images

I am considering a software issue but i am afraid if i try to install a fresh image will block in the middle of the process and brick my reciver

any advice will be highly appreciated

 

[carmine]

please delete you in box for pms i tried to send you a pm

 

[ks2013]

Can someone advise if this is the right capacitor to replace with.

http://www.maplin.co.uk/p/220f-35v-105c-radial-electrolytic-capacitor-n86kf

Thanks

 

[timofee]

That will work fine. Also it is a good choice as it is a higher rating in having both higher voltage and higher temperature tolerance than the original capacitor.

 

[adm]

That will work fine. Also it is a good choice as it is a higher rating in having both higher voltage and higher temperature tolerance than the original capacitor.

True and possibly OK for this application. Ideally it also has to be low impedance (low Z) and Maplin do not claim that for that capacitor. They do even state the manufacturer so a search on the Web for a full data sheet is pointless. Check the physical size - the packaging for a capacitor that has a higher voltage rating may/will be larger - usually height and in a power supply there is usually plenty of room for a taller component.

Alternative UK supplier for reputable capacitors

http://cpc.farnell.com/rubycon/35yxf220my1013/capacitor-low-z-35v-220uf/dp/CA05108

data sheet

http://www.farnell.com/datasheets/14936.pdf

http://cpc.farnell.com/panasonic-electronic-components/eeufc1e221/capacitor-220uf-25v/dp/CA05151

data sheet

http://www.farnell.com/datasheets/94578.pdf

Rapid Electronics (UK based)

https://www.rapidonline.com/samwha-wf1v227m1012m-220-f-20-35v-105-c-low-imp-radial-alum-elect-capacitor-11-3928

You may/will be able to find the same manufacturers part numbers on a well known auction site but possibly buy from a UK supplier with a high feedback score.

 

[timofee]

I fitted a Mаplin capacitor in a VU+ Duo1 and it has been working faultlessly for four years.

The original capacitor fitted by VU in the factory failed after a year or so.

 

[b13orn]

hi there are no capacitors on my board??? all 3 in that row look like a brown strip between negative and positive is there an upgrade

 

[timofee]

The faulty capacitors are only present on the original production on the VU+Duo1.

The later VU+ Duo1 versions have much smaller integrated capacitors. These are not known to fail as frequently as the originally used capacitors.

In any event, this repair guide does not apply.

 

[io2345]

I replaced C807 with a Tantalum-type now, 220uF 16V. Hope, it will last longer. Changed it already two years ago (with a standard Electrolytic-type though).
If you are not into electronics pls. note, that Tantalum Capacitors have marked the + Wire (not - like the Electrolytic ones).

The Duo is still working fine for me. I'm on latest OpenPLI

 

[adm]

I replaced C807 with a Tantalum-type now, 220uF 16V. Hope, it will last longer. Changed it already two years ago (with a standard Electrolytic-type though).
If you are not into electronics pls. note, that Tantalum Capacitors have marked the + Wire (not - like the Electrolytic ones).

The Duo is still working fine for me. I'm on latest OpenPLI

Fit them round the wrong way and they will immediately glow cherry red before producing the magic smoke. If you are unlucky red hot capacitor casing will fly towards you at high speed

Tantalums have the habit of failing short circuit whereas the electrolytic capacitors originally fitted fail more gracefully - the capacitance and internal resistance changes.

"Standard" 85C Electrolytic capacitors seldom last that long in a switched mode power supply. Ideally the replacements should be designated impedance (low Z) or Low ESR (Equivalent Self Resistance), be rated for 105 degrees Centigrade operational, from a reputable brand such as Rubycon, Panasonic or Vishey etc. and purchased from a reputable source.

 

[io2345]

I replaced C807 with a Tantalum-type now, 220uF 16V. Hope, it will last longer. Changed it already two years ago (with a standard Electrolytic-type though)....

One month later the red light symptom was back from time to time. Puzzled, I fiddled out the Mainboard. Did ever someone find something like that before?:



Important thing that we learn from that: C807 is only one out of three capacitors, it is in parallel with C814 and C850. So, if your box won't start after replacing one of them, replace all three of them.
In order to be prepared for a quick replacement I extended the wires now. Not beautiful but works:



=============================================

Information for people who have trouble to tune certain channels: I tried the hack of @addicted (Post 28 of this thread). C848 indeed has something to do with tuning problems (If it's missing, you can't tune any channel, in fact). Working fine now. Thanks apply to @addicted for this.

 

[adm]

View attachment 64163

With those bare component leads you stand a good chance of them shorting out to the tops of other electrolytic capacitors on the board.

 

[io2345]

Those are solid copper wires, no flex (stranded wire). Unless you throw the box, they will stay in place. But, of course, you are right - it would be better to insulate it...

 

[littlejim]

There can be be cases where the inductance of that length of wire would be enough to cause problems.

If you use the right parts, and parts that don't date from the capacitor plague when a lot of manufacturers were using a stolen faulty recipe for the electrolyte in the electrolytic capacitors, they will not need replacing again.

View attachment 64162

That looks like a weird bodge too. Not a great idea to rely on the green solder resist as an insulator.

 

[adm]

There can be be cases where the inductance of that length of wire would be enough to cause problems.

While the capacitors may be decoupling the power supply they don't appear to be part of the power supply board where filtering of high frequencies are more important.

If you use the right parts, and parts that don't date from the capacitor plague when a lot of manufacturers were using a stolen faulty recipe for the electrolyte in the electrolytic capacitors, they will not need replacing again.

While I agree I'm not sure it as simple as that. I read a report from a reputable manufacture that indicated that with even the correct electrolyte some manufactures were attempting to miniaturise one stage too far. All the reputable manufacturers of electrolytic capacitors seem to have the same physical can size for the same voltage/capacitance rating whereas some of the capacitors coming out of Korea were/are smaller. Given that it was mainly Korean manufacturers that were using the stolen recipe (and got it wrong) this may be true. In my experience capacitors made by SamYoung (not Samsung) and various other brand names close to those of more respected electronic goods manufacturers do tend to fail more quickly than their specification sheet suggests.

The life expectancy of a capacitor rated at 105 degrees centigrade may be only 2000 hours AT THAT TEMPERATURE but for EVERY 10C below that perhaps double the life expectancy figure. That's why it's recommended to use a capacitor rated for 105C operation rather than ones rated at the more common 85C. It's the operational temperature inside your box that matters which could easily peak at 50C+ and if the capacitors are in the power supply they could be physically close to a very hot heatsink. The price difference between a general purpose capacitor and better rated one may be of the order of 10p and often it's only the better temperature rated capacitors that have a low ESR suitable for switched mode power supplies.

That looks like a weird bodge too. Not a great idea to rely on the green solder resist as an insulator.

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