Hi all, I wasn't quite sure where to post this thread as I am a newbie and are still trying to workout the forum, so sorry to the moderators in advance for this. My power supply had a minor fizz and i was after a bit of help in identifying the part? I think it's a resistor marked "R5" on the board and has a code 47XX? see pics attached. The XX part of the code has been burnt away? I tried contacting the company via aliexpress but all of a sudden a repair enquiry gets a cold shoulder! Go Figure!! If anyone has an idea about that component I'd love to hear from you. Your help will be really appreciated. Thanks.

 

Looks like it says 47R0. Which translates to 47 ohms.

 

Yep deffo a 47R, looks like it.

 

You will probably find that either or both of Q1 and Q3 is now short circuit in which case there are likely other components blown too.

 

Hello,

As @AlbertHall said, check the transistors.
I see that Q3 is not correctly screwed on the heatsink, so it may have overheated.

Bertus

 

R2 nd R5 look like respective 'gate stopper' resistors for Q1 and Q3 respectively, so 47 Ohms would be an appropriate value. Agree with Bertus about Q3 mounting/overheating.

 

Hi All thanks so much for identifying the 47R0 and your advice and input. Also great observations on the Q3 not being snrewed in you guys. I will replace R5 with a new 47R, screw in Q3 and check both Q1 & Q3 for shorts along with other components. Hopefully that does the trick. Thanks again to All

 

Still wondering what that "chinese" in the title has to do with the technical side of the problem. Had you said "Spanish" instead, or "Peruvian" or..., it would be still the same...

 

Still wondering what that "chinese" in the title has to do with the technical side of the problem. Had you said "Spanish" instead, or "Peruvian" or..., it would be still the same...

I always preface my phone as a Chinese iPhone, don't you?

 

I always preface my phone as a Chinese iPhone, don't you?

First, I ignore where my two mobiles come from and second, aren'the they all nowadays?

 

First, I ignore where my two mobiles come from and second, aren'the they all nowadays?

I think it is funny that the highest quality devices in the world are coming from China (iPhones) and people still say stuff like "Chinese Power Supply".

there are a lot of countries that could be inserted in the blank, "_______ power supply" statement that I would cause me to raise an eyebrow and question quality. China is not one of them. China offers a wide range of qualities for all consumers but the fact it is made in China has nothing to do with the quality. If you buy an 8Amp bench power supply for $35, I think you'll likely get all the quality and durability you can expect from a $35 bench power supply.

 

I recall in the late '50's early '60's when Japan also was flooding the market with goods, transistor radios etc, and there was much outcry with 'Cheap Japanese Junk'.
Like many eastern countries, they did not go through an Industrial Revolution like the west, hence they had to use western models of products in order to make copies and learn.
A couple of the typical items were German camera lenses and UK motor cycles.
In some cases, to the chagrin of some, some knock-offs were better than the originals.
I recall visiting a Japanese CNC company office based in the US in the 90's, they had a handout blurb on the history of the company, at the turn of the 20th century they were making rush baskets, at the time I was there they were a world leader in CNC machines.!!
There was a significant gap from 1940-1945
Max.

 

Yes Max, I recall the first YAESU ham equipment I run across versus the FT901DM I bought maybe 30 years later!