Re: Another help question. power supply

From: tommoni <tommoni_at_email.domain.hidden>
Date: Thu, 22 Mar 2007 07:33:25 +0100


in the schematic schemview.php?id=1419 you can see CR11 (two diodes in one housing). I think this one has ONE corrupted diode. It's very unlikely that all two diodes have a shortcut. So you can measure them both and there should not be a significant difference. As I'm not so familiar in technical english I try do describe with my own words what you'll have to do to get this fixed:
Keep the power-supply off for approx min. 10 minutes (better a few hours) so that all electical components could discharge themselves. First you do not need to unsolder sth. because the fault is very uncritical, you will get two really different results in measurement, when you connect one pin of CR1 on the soldering side with the kathode (=housing of that dual-diode) with an ohm-meter. If you have a "modern" multimeter, then use the "diode-test"-function and you should get the result "infinity" (and after switching the red and black measurement-cable, you'll get 0.5 up to 0.8 volts as result for the diode) if the diode is still working. There are minor variabilities, because the surrounded components may determine the results, but not very much.
IF YOUR DIODE IS BAD, the you'll get either ZERO ohm (or ZERO volts in diode-test-function). It doesn't matter wheter you connect the red cable with the anode and black with kathode or reverse: you'll always get nearly zero, because the diode is bad = shortcut You'll then have to replace it with two single diodes with the following data: 50 V and 25 A or more than that. Perhaps you'll still get the original dual diode, or a similar one with the same connections: two anodes = pins and kathode = metal-housing. And keep an eye on cooling the diodes, if you'll not get the original one :-)

I hope my description was not to gramatically bad :-) But I'll speak very much better german than english greetings: TOM from Bavaria, the center of europe, the country with the marvellous castles of Koenig Ludwig, the alps and the original Octoberfest in munich

Am 21.03.2007 um 21:59 schrieb Patrick Garber:

> O my bad did you mean The huge mj8505 transistor? I was told that
> I could replace with MJ16018, It would be easier if you could tell
> me what to check based on the number from the schematic I have.
> from
> Because I am so lost on this, I must be stupid today so sorry
> everyone.
> Patrick

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Received on 2007-03-22 10:09:49

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