Repairing the power LED circult of a PS-018 220v-100v step-down transformer

In 2010, my original SCPH-10000 came with this step-down transformer... which appears to actually belong to a SCPH-39001 console that I returned for an exchange (And it's how I got my SCPH-39006).

The exterior is cracked (Perhaps the previous owner found it fun to throw it around?)... and the power LED was never working. It has "PSX2" printed on it's cover.

Today, I've taken this adaptor apart to fix it's casing, and I found that the power LED was not working because one of the wires that connects it to the transformer itself seems to have been burnt.

At first, I thought that it would be a simple resoldering job... until I noticed that the burnt wire seems to have an electronic component as part of it. :S

The problem is that component does not seem to have any numbers nor markings, and I am not trained to work on such high-voltage devices. Unless I am sure that nothing can go wrong after replacing the component, I will not attempt to fix it.

So... has anyone here seen this step-down transformer before, and can anyone tell me what is this electronic component that I should replace? Thanks!

 

Resistor

 

Thanks. Any idea what value it is?

 

WOW! What a crap!
Measure the V between the two point where's the led is collegated and tell it to us. I give you the right value
Be carefull !

 

Thank you.

I connected my multimeter to the wires that the LED should get connected to, and the results are... weird.

I think that it's actually ~110 V AC, as it's nearly no voltage indicated when my meter is set to 50V DC and it greatly exceeds the 10V DC setting. Plus it causes the needle to jump around, so the current seems to be alternating. (Actually, it should be AC anyway, since that box contains only a step-down transformer with no other electronics for voltage/current regulation)

When set to the 250V AC setting, my meter reads about 115V. So the LED was running on 110V? :S

Well, in the event that I cannot fix this, it's no big deal. The unit itself is working properly, but it's LED is the only part that isn't functional.

 

Wow not cool. You maybe able to replace it with a neon light as opposed to a led.

 

I think it's very strange that the led is connected to alternate current source, also directly at high voltage :S
The simplest solution is to use a simple diode ( best two) to conver AC to DC and use a 5.6 Kohm resistor (5W)
But, honestly, i don't like this solutions :|
This solution it's pure crap as that converter itself...

 

Thanks guys!

In the end, this is just another badly designed device, probably from a Chinese company from somewhere in China. It doesn't even seem to output 100V as printed on the cover, but about 115V (So probably around 110V under load?).

EDIT: Unless, this raised output voltage is caused by me plugging it into the 230V (Instead of 220V as printed on it's cover) mains here. :S
But that..'s STUPID! D:

The only reason why I bother getting this restored is because it looks... 'meant' for the Playstation 2.:loyal:

Thank you very much!

Tell me, what's wrong with that simple solution?

I came across something similar when searching the Internet, and usually people say that it's just not good because it doesn't protect the LED from voltage flucturations (But they don't say that it's bad otherwise?).

Thankfully, the mains here has always been stable at 230V, for as far as I can remember. Wouldn't that mean that such a simple solution would be good enough, or do you mean that it's just not a good solution for some other reason? Will it heat up greatly or waste a lot of power anyway? :S

People say that a (1N4003) diode would be used to prevent the LED from being destroyed by the negative AC phase, but why do you recommend two diodes be used instead of one? (For better heat dissipation?)

I see that a diode bridge is used for converting AC to DC, but they consist of 4 diodes instead of 2.

 

An LED is a diode.

 

A LED is a diode with low break-down voltage tolerance. I read that feeding it a too high voltage in reverse will destroy it, hence the need for a stronger diode... unless you are saying that the LED itself will be sufficient.

The original circuit doesn't seem to have an extra diode in it though. :/

Another thing that I'm now curious to know is why master991 recommends a 5.6K ohm resistor. On some other sites, the calculations show that a 4.7K (At a much lower wattage too, like around ~1W) resistor is already sufficient. Sure, a resistor with higher ratings would be safer, but I would like to know why.

 

I never said it would work. Just that "you need a diode" is overly vague, as LED is a diode. Obviously just an LED can work, as it has done all these years.

Id probably just use a rectifier to convert to DC to avoid any hassle though.

 

I recommende a diode (better two, one for ande anode other for catode or in parallel for better heat dissipation) to rectifier the voltage. Led it's a diode (better, semiconductor) but can easly destroied with reversed voltage (as mentioned sp193 has low break-down voltage ) also a led should be used as a light source, not a rectifiers too
The "classic" 1N007 would be perfect.

I say a 5.6 Kohm resistor because in my country (italy) we use IEC 60063 for standard value of resistor and I can't find a resistor with the value of 4.70K (plus bigger value is always better due to tollerance )
For the vattage a 2W resistor is sufficient, but with the crappy design of that piece of shit the resistor start blown as the old one. So 5W it's better
@SP193: They don't use the diode because that AC\AC converter it's very very economic

That it's the Graetz bridge. But one diode or two are enogh for the scope

 

My point was, you just said "a diode"

There are many types of diode, not all of them are sufficient for the task. If it was a case of any diode working - an LED is a diode.

 

Wrong interpretation due to my "mental" and fast conversion ENG-ITA. Now I understood what you meant Bad_Ad84.
Sorry

 

Thank you very much! You have been a lot of help here.

I'll try to get the replacement components tomorrow, after work. As an added bonus, I might add one more 100V socket to the unit, so that I can power my external HDD unit without my other step-down transformer.

 

Neon....

http://www.circuitspecialists.com/110v-neon-indicators

 

Thanks, but I would rather retain the original design. Plus there is also nearly no space left behind the LED, as the transformer was strangely put right in the centre of the box (And so it makes most of the space at both ends unusable by anything too large).

One more thing guys, I took apart my other 220-110V step-down transformer (PowerPac PP60), and saw that they are using a 100K ohm resistor (Seems like a 1/2w) with the LED, without a diode as well. Is that safe? I mean, is a 1/2w resistor safe?

I think that I'll copy what is being done in that step-down, as it was done by a company with a brand.... only if the 1/2w resistor certainly won't burn up when I switch the step-down transformer on.

 

Just go to maplin and buy this cool step down with led on a switch http://www.maplin.co.uk/300w-uk-to-usa-voltage-convertor-265288

It works on usa japan xbox and ps2 saturn and many more.

 

Knowing SP193, even if he did actually buy a new stepdown transformer, he would still try to fix this one, if it is just for the learning.

 

Agreed!

Well, the thing is... both my step-down transformers are working fine. The only thing that doesn't work on this one is the LED lol.

The PowerPac one stopped working - as one of the solder joints cracked off the board with the copper trace when I opened it... however that happened -_-" (Badly made in China?).

I've figured out that it uses a 100Kohm resistor as the connector will output 220v instead of 110v, if the unit is set to step-up (110 -> 220) instead of stepping-down (220 -> 110) the AC mains.