Mastervolt Battery Charger does not start

[westernman]

I have a Mastervolt Mass 12/60 mains powered battery charger. However, it does not easily start when plugged into the mains and this has been getting much worse of the last few months. It is usually possible to get it to start by juggling with the mains on off switch. The sequence seems to be to turn off the Mastervolt, turn on the mains, turn off the mains, turn on the Mastervolt at exactly the right moment and as the leds on the Mastervolt are dying turn on the mains again and sometimes it will start up.

I was told by a guy from Mastervolt on their stand at the Paris boat show a few weeks back that this is a symptom of a couple of capacitors which are dying. It seems to be a common problem. He promised to send me some more information if I emailed him the model number and serial number which I did. And he didn't.

So can anyone else shed any light on this?

If it is a couple of standard capacitors I could get some one to change these easily at work rather than going to the trouble of sending it off to Amsterdam or where ever it needs to go to.

It is a Mass 12/60, Part no. 041010610, Serial no. L625 H 007

 

[davidwf]

If its capacitors failing chances are they are Electrolytic, if you open it up you should see the failed ones as they will be blown, ie their tops will not be flat. If there is any discharge do not touch with bare hands it's not nice stuff. If they are blown you should be able to get replacements from CPC or Radiopares, buy the better quality ones.

Make note of stripes on capcitors as you remove them. Take a photo.

When replacoing make sure the stripe goes the right way round they are polarity sensitive.

 

[savageseadog]

It's not too difficult to change them if you're experienced but wouldn't recommend it if you're not. However I would be surprised if the capacitors are faulty, you don't say how old your unit is but they are normally reliable components for 10-20 years if not misused. There is the possibility that they're underrated for the job they're doing, the cause could possibly be ripple current, something that can be forgotten by designers.
Another possible cause can be your batteries being faulty or a wiring fault, I don't know this particular unit but there might be sense wires as well as charging wires. You need to check your wiring thoroughly (not with a normal meter)

 

[westernman]

As I said, the Mastervolt guy on their stand at the Paris boat show immediately recognised the symptoms and said there were two capacitors which needed changing.

I just don't know which ones. I can't see anything obviously broken - no bloated electrolytic capacitors or anything else.

 

[savageseadog]

As I said, the Mastervolt guy on their stand at the Paris boat show immediately recognised the symptoms and said there were two capacitors which needed changing.

I just don't know which ones. I can't see anything obviously broken - no bloated electrolytic capacitors or anything else.

Capacitors don't always reveal their faults, it is possible to test them. Check your batteries and wiring first, stock answers (fob offs) are easy, salesmen are invariably silver tongued and know bugger all. Your response in retrospect should have been to say I'll send it in for free repair quoting your name as it's obviously not merchantable. I'm not saying you have been fobbed off but always start at the start.

 

[lw395]

For what it's worth, I've just fixed a power supply which had failed due to a capacitor.
It was the electrolytic immediately after the bridge rec.
These things have lives of a few thousand hours at their rated temp, mine had been in almost continuous use for a few years, so I cannot really complain. I used it to float charge a group of 12V batteries.
I replaced with a higher temperature rating, higher voltage rating Panasonic branded part for a couple of quid.
The old cap was clearly heat damaged, and as I desoldered it, it left one lead behind!