Red Light with Starting....

[jakspratb]

Looking for a bit of help, I've read the posts about problems with capacitors burning out on the Duo + receiver. I've taken the casing off and I thought that maybe I had the same issue on C807? The screen shows the red light and starting... Nothing is shown on the TV at all.

Box is original and just less than 2 years old.

Any thoughts on what else it could be if nothing seems burnt out?

Thanking you in advance

4847048470

[bellejt]

if under warranty back to seller.

[khan888]

It could still be the C807 Cap. I replaced one a few weeks ago which looked ok and solved the red light issue.

The ones installed on your receiver look like surface mounted capacitors (smd)


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[jakspratb]

Hi, thanks for your responses, where would be my best place for picking up one of the surface mounted caps, somewhere like maplin? I'd guess these are pretty simple to change over, heat the solder and remove what's there, replace and re solder back in?

[abu baniaz]

You can use the big ones. Easier to work with.

[adm]

The large electrolytic capacitors - which are the ones that go in many power supplies from many manufacturers - are unlikely to be surface mount components. There are some surface mount capacitors on the board but these will all be small values and 99.99% unlikely to fail.

The other round surface mount components are inductors. The silk screen legend (printed text on the board) looks like they are all identified with the letter L - hence inductors.


The C807 will be an electrolytic capacitors and will be one of the larger round components approximately 20mm high.

A guide can be found at
http://www.world-of-satellite.com/showthread.php?26735-Redlight-of-Death-Repair&highlight=C807

However the capacitor suggested there is NOT one I would recommended. It's only rated to 85 degrees centigrade and Maplin doesn't specify a low ESR (Equivalent Series Resistance). This is a general purpose capacitor and NOT the type recommended for switched mode power supplies.

You need a capacitor rated at 105 degrees centigrade and one specified with a low ESR or Low Z (Low Impendance)

Perhaps a 220u 16V from an UK Ebay seller of Panasonic or Rubycon capacitors, for instance


http://www.ebay.co.uk/itm/5-X-Panasonic-Ultra-Low-ESR-105-Degrees-FR-Range-Radial-Electrolytic-Capacitors-/351313817882?var=&hash=item51cbef711a:m:mXXzjM9N4LmjUbHFqKMqSxw


By the way, when an electrolytic capacitor fails you may not see any physical damage. You are highly unlikely to find burn marks. You may find the top of the can bulging or when removed you may find a sticky wet patch on the board where the capacitor has leaked - but often in the minority of failures.

Example of bulging


https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSvvFfxj88BneG5udntmWBX5vOGyThi_ 0KrCw75xOq9x1QyX6Vd4w


The score lines on the top of the can of the capacitor are deliberately designed in to be a weak point so it ruptures rather than exploding.

[abu baniaz]

The picture quite clearly shows that SMD capacitors are used for C807 and the other two near it.

There was a big thread on LSS where someone bought one (not from the sponsor). It went faulty, he contacted the seller. The seller accused him of altering it and refused to honour the guarantee. IIRC, the sponsor contacted Vu and confirmed they had indeed started to use SMD capacitors in a bid to put an end to the red light issue. Obviously this has not worked.

Use good quality parts as recommended by ADM, and you should be fine. Best not to trying switching the unit on until you replace the capacitor as you risk the regulators going faulty.

[adm]

The picture quite clearly shows that SMD capacitors are used for C807 and the other two near it.

There was a big thread on LSS where someone bought one (not from the sponsor). It went faulty, he contacted the seller. The seller accused him of altering it and refused to honour the guarantee. IIRC, the sponsor contacted Vu and confirmed they had indeed started to use SMD capacitors in a bid to put an end to the red light issue. Obviously this has not worked.

You are correct C807 is a surface mount BUT it will NOT be a large value.

Irrespective of the technology a 200/220uF 10/16V capacitor is going to be physically large and comparable in size to those non-surface mount capacitors in the cans nearby on the circuit board. My guess is that the manufacturers have changed the circuit and have replaced C807 with something like a ceramic plate 0.1uF capacitor. These will not fail. Without a circuit its hard to diagnose what may now be failing.




Use good quality parts as recommended by ADM, and you should be fine. Best not to trying switching the unit on until you replace the capacitor as you risk the regulators going faulty.

While I stand by my advice about using better quality capacitors rated for switched mode power supplies in this case it will not be C807 that has failed. I'll almost guarantee that the component now fitted to that board in position C807 will not have failed.

[wullboy]

Hi, is this Schema Diagram any good guys....