Electronics help

[T i m]

Whilst I get what you are saying (and given limitations like the cost of some diagnostic equipment), you can sorta 'see' what's going on with some electronics by using a simple DMM or even an oscilloscope (and you can get PC based / USB jobbies quite cheap these days) or even just an LED and resistor. ;-)

As has been mentioned elsewhere, the 'problem' with diy fixing SMPSU's is the high voltages often flying about, the frequencies and the closed loop'edness of them.

One of the common problems with them (and PSU's in general) is capacitors going bad but you can often spot them and if done soon enough (like if something starts misbehaving rather than failing outright as such) you can often save something from dying in a more complicated way. ;-)

Cheers, T i m

[ss]

Update:

I got the other charger working, replaced the fuse and no joy, it turned out the fuse holder was faulty so replaced that and all ok now.

As for the other I may as well get a replacement for the faulty diode and see what happens, now out of interest more than anything else due to the other charger now working.

Thank all for the input and help given.

[Archibald Tarquin Blenkinsopp]

If it's not "information overload", I never had a supply blow one rectifier.

The current that flows in the duff reccy invariably takes the other out simply because you now have a mains input with a diode across L-N.

The fuse is no protection for the diodes, semiconductor rated fuses would have no place in a SMPS feed.

I always replaced all four, they were cheap and technically two should survive and not have sufferred any "trauma", but replacing all four was a certain way of avoiding the pitfalls of erronious identification and meter prods that might not have had a good contact.

On a plus point, I bought some reccys from Ebay for my Polaroid TV, I was amazed at the price, If I were back in the trade I'd be buying them in in the kg

If you are throwing any PC's out, the PSU's contain four suitable mains recs. Even if they are cheap, it's not good to spend cash on something you may have stashed in the shed.

AB

[tabbypurr]

lots of PSUs do, and they don't need to be 1N3599s (or whatever they were) but I expect the OP doesn't have suitable junk lying about nor could identify which diodes would be suitable & which not.

NT

[ss]

I do have an old PC and monitor was broken but with the help from here managed to get it repaired so keep as a spare. Yes I would probably struggle to indentify suitable components. I do Have loads of junk but mechanical stuff rather than electronic.

The diodes on ebay will cost under £2 for pack of 4 so will just go with that, easiest option for me.

[tabbypurr]

re) but I expect the OP doesn't have suitable junk lying about nor could id entify which diodes would be suitable & which not.

sounds good. Maybe this sort of thing will spawn a new market for 100w filament lamps.

NT

[tony sayer]

Agree on that look for swollen ones..

[Cursitor Doom]

Sorry, not read this from the beginning so don't know which diode you're referring to. Some diodes you can just replace from whatever you find in your junk box and they'll work just fine. HOWEVER, if your SMPS runs at (for example) 20khz (some run much faster) then you will NOT fix it by replacing the diode with another common-or-garden rectifier device. For these you need a *fast recovery* diode. The low junction capacitance of a FRD can make all the difference between it working or not. They're not expensive, but you're highly unlikely to have one lying around. I'm sure CPC Farnell have them for peanuts, though - order over internet.

[The Natural Philosopher]

Its the mains input side, dear, running at 50Hz

[Archibald Tarquin Blenkinsopp]

Do you not mean MAINS or maybe *running* at 50Hz

or are his keyboard acrobatics related to the stupidity of the gibberish :-)

God help any poor soul in the NG that does need assistance :-(

AB

[tabbypurr]

What is this guy's issue? In case there's any question TNP's comment was correct, and any old diode can not be used, though a good many can.

NT