Re: "easy" PSU repair
it draws less than 0.1 mA. literraly i cannot even measure it because my multimeter dont have that low scale
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"easy" PSU repair
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Re: "easy" PSU repair
transformer with a short in the primary will still work but draw more current (reduced resistance)
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Re: "easy" PSU repair
It could be that the top224 is damaged, if everything else seems to check ok
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Re: "easy" PSU repair
it does matter?
nothing gets hot so it will be miliamps
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Re: "easy" PSU repair
before this goes any further,
you blew the fuse - did you find what blew it yet?
because that's not related to output voltage.
do you know the current it's drawing from the mains?
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Re: "easy" PSU repair
try to remove it but nothing changed
if it is connected in blocking way to plus it can stay there
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Re: "easy" PSU repair
Have you tried removing it to see if the voltage will come up? It could be breaking down when there is voltage on it.
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Re: "easy" PSU repair
What about the diode across the 12 volt output? what is the number on it? I asked about it in post #26 (the one in the yellow box)
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Re: "easy" PSU repair
i replaced both diodes VR1 and D1. VR1 is that P6KE200A and D1 i just throw some diode laying around. i check it now and its B360A 3A shotky diode. it's rating is only 60V but it dont blow so it is good :-)
when i remove that 1A shotky diode nothing changesLast edited by ktmmotocross; 01-26-2019, 01:10 PM.
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Re: "easy" PSU repair
You can't have a regular diode across the 12 volt output (My picture post#26)
I see the diode you replaced in your picture above(post#27) Which diode are you replacing? If you look at the schematic, is it VR1 or D1 ?
That diode you are using to replace VR1 is a p6ke200a that should be okLast edited by R_J; 01-26-2019, 01:01 PM.
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Re: "easy" PSU repair
yes that diode is 1A shotky, looks like it was nor replaced
that big diode have on it P6KE200A 4702
removed that capacitor but voltage not risesLast edited by ktmmotocross; 01-26-2019, 12:51 PM.
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Re: "easy" PSU repair
This diode is a 1 amp shottky diode? This should be a Zener diode.
And you replaced the P6KE200 with the proper tvs diode, correct?
Do you mean that chip cap across the output diode? just remove it for now and see if the voltage comes up.Last edited by R_J; 01-26-2019, 12:43 PM.
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Re: "easy" PSU repair
all resistors chcecked outside of board and is ok
that P6KE200 diode is a zener diode that i replace earlier for just diode that it meant to be
That diode on output is 1A shotky barier diode
across output diode i found broken capacitor. dont have its parameters so i just throw in some capacitor laying around without know its capacity,is it a problem?Last edited by ktmmotocross; 01-26-2019, 12:17 PM.
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Re: "easy" PSU repair
This seems to be how the feedback is connected, Are the resistors ok ?
There is a diode across the output, Is this a zener diode?
when i measure components on this PSU i see that this two diode was shorted, so i replace it with two normal diodes.
how can i know the value of that zener diode when i dont have original diodeLast edited by R_J; 01-26-2019, 12:02 PM.
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Re: "easy" PSU repair
so what can be checked next? as i check optocoupler so there must be something bad elsewhere
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Re: "easy" PSU repair
If you loose the feedback you want the voltage to go low, If there was a problem with the feedback circuit and the voltage went high, it could reach 20-30 volts which would not be good.
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Re: "easy" PSU repair
It looks like you have 0 volts on the opto, so the internal led is not lit, I believe you should have at least 1 - 1.5 volts
I can't see how the traces are run so its hard to diagnose. The diode in the picture covers the traces.
Is the circuit close to the diagram I posted ? does one of the pins of the opto connect to the 12 volt output?
What is the number on the optocoupler?Last edited by R_J; 01-26-2019, 11:06 AM.
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Re: "easy" PSU repair
i made a test circuit with 6.5V PSU and multimeter in diode mode and optocoupler was working.
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