Hi everyone,

On the last year, i’ve been becoming more and more interested on learning how to make and understand electronic circuits, but for now i am still in very basic learning, so after seeing some posts from this fórum i decided i had to register on it, as it has soo much to offer and maybe i can also help others allong my own learning path, after all it’s learning and helping others to learn that we all learn better right?

So in this first post, i will tell you the tools i have, the tools i’m thinking buying, and the problem i have in hands more recently!

I Have the regular electronic enthusiastic equipment, two soldering irons one with a bigger tip and one with a smaller tip, the solder paste, solder pump, very basic soldering base to hold small circuits on which i work on, a DMM and a good counter with light to work on!
I’m thinking latelly on obtaining a solder station with hot air and soldering iron, i’ve been seeing some on ebay from the uk or even some chinese ones. But not sure about the quality of them, so that’s still a thought for now, maybe you can give some advices about some good and cheap stations that i will be able to order to Portugal, if you do, that’s one more thing i will thank you really very much, because as i told you before, i’m just starting on this, and i’m affraid from making error buying some piece of equipment that don’t serves me well.

Now, here it goes the problem on which i’m asking for your help!

About na year ago, i made a carpc for my car, and i was able to successfully put and mount everything together, it hás been working flawlessly for about this last year that passed, but some time ago started giving me some problems, and yesterday the psu stopped working.

My carpc is composed by a D945GCLF2 motherboard, 2gb of ram, a 160gb hard drive, several usb devices as gps, rádio, bluetooth, wireless usb card, wireless keyboard, obd2 device connected to the car, reslers device to use the steering wheel buttons on the carpc, and two extensions of usb ports that i put on the car’s front center console.
Powering all this was a M2 ATX chinese clone with 150w of power psu.. it never gave me any king of problems untill now!

What i did untill now, tested the motherboard, it’s working as all of the connected devices, so the problem should be the one and only PSU, tried the psu on the counter, with the green and black wires connected, and as i thought it hás no output power, but the input it’s there, i tried to locate the inline fuse, since this m2atx clone doesn’t have a mini blade fuse as the original one, but that didn’t served me for anything except to blown up without wanting so a component on which a wire touched :/

I’m hoping maybe i can substitute that component with your help on identifying what i should puto n it’s place, and after that, to locate the source of the original non-working problem!

Before anything else, i want to thank really a lot to anyone who reads all of this, and tries to help me, and sorry for the mistakes on english, but i’m portuguese, and i don’t practice my english as much as i would like to.

Well, here it goes some photos of the psu board, first one of the entire board, and next the board on 3 photos to see better on detail, any more photo of some particular área please tell me, and i will post it asap!












Regards, and once again thanks for everything!!

 

Instead of using outside hosts for your links, why not use the local albums here on AAC. They are free and it works better overall. I suspect you are still editing while I type this. Happens to me all the time.

By the way, welcome to All About Circuits!

 

Hi,

Thanks for the welcome message, and for the advice

It was as you said, i was editing the post as you were writing yours, i was trying to see what was the best way to add images to the post! I decided on posting images outside from the forum, because of the size of the images, if i put the images on the forum album they where very limited on size and resolution, and this way i can have both! Or are there any more option to add images without loosing the needed resolution to check for details on the circuit?

Once again, thanks for the quick reply and welcoming message on this first post of mine

regards

 

The white square smd is a fuse, check to see that it is good.
Not sure on the capacitor, looks like something shorted it out and left some extra copper.

Need a photo of the back side to determine what that is a part of, looks like a a capacitor, maybe part of a voltage sense line, if the resistor is open the supply should shut down, but should still work with the cap removed.

 

Hi 3ldon,

Thanks for replying my thread!

Is this the one that is a fuse?

I was suspecting that too, but when i put the dmm on it, it tells me that one of it's sides is positive and the other negative! It that supposed to be like that?

And here it is one image of the back of the psu!



Once again, thanks for replying!

 

Hi,

Thanks for the welcome message, and for the advice

It was as you said, i was editing the post as you were writing yours, i was trying to see what was the best way to add images to the post! I decided on posting images outside from the forum, because of the size of the images, if i put the images on the forum album they where very limited on size and resolution, and this way i can have both! Or are there any more option to add images without loosing the needed resolution to check for details on the circuit?

Once again, thanks for the quick reply and welcoming message on this first post of mine

regards

The local attachments don't have the same restrictions, and you can still display them full size.

How to Display Attachments Full Size

Bill's Index

 

The white square smd is a fuse, check to see that it is good.
Not sure on the capacitor, looks like something shorted it out and left some extra copper.

Need a photo of the back side to determine what that is a part of, looks like a a capacitor, maybe part of a voltage sense line, if the resistor is open the supply should shut down, but should still work with the cap removed.

Hi 3ldon,

Thanks for replying my thread!

The one you are saying that is a fuse is this one?

I was also suspecting this one was a fuse, because it's the location of the mini blade fuse on the original M2 ATX PSU, but when i put my multimeter on it, one side was positive, and the other negative! Is this the way it should be?

And here it is a image of the back of the PSU:
[url=http://img693.imageshack.us/img693/2666/p1060111z.jpg]
[/URL]Once again, thanks for replying!

Regards

 

The local attachments don't have the same restrictions, and you can still display them full size.

How to Display Attachments Full Size

Bill's Index

Hi once again Bill_Marsden,

Once again, thanks for the advice i will have to check that out, but still i'm affraid that if i put the images in full resolution here on the page they would occupy the entire page that's why i opted for putting a image on the outsource, because it allows us to see the image and maximize it gradually as needed, but still, i will really have to check that out!

Regards

 

Can someone please help?

regards

 

Do you have a schematic for this sucker? It is pretty impossible otherwise, just a bunch of guesses.

 

Give me a reply if you want it done.
or is it working now, cause I missed tis thread.

Rifaa

 

If u got the guts to tackle the PSU, then I can guide you.

Rifaa

 

Do you have a schematic for this sucker? It is pretty impossible otherwise, just a bunch of guesses.

Don't have a schematic of it, and dont know if there is any on the web, but thanks for the quick reply, i will try to find one and if i find, i will put it here!

regards

 

If u got the guts to tackle the PSU, then I can guide you.

Rifaa

Hi Rifaa,

Thanks for replying my thread, i have the guts to do it, only need someone to tell me what to do, and i will try to learn quick so that i won't bother you too much!

thanks once again!

regards

 

OK..
Gimme a few minutes to study the pics and I'll let u know.
Keep a lazy eye on this thread...
Cause I might reply suddenly or after a few hours....

Rifaa

 

OK..
Gimme a few minutes to study the pics and I'll let u know.
Keep a lazy eye on this thread...
Cause I might reply suddenly or after a few hours....

Rifaa

Ok! Thanks a lot for helping me! I really thought i was in a dead end here! maybe i can still recover this psu with your help

regards

 

I have edited one of the pic and below are the references.
Remember to answer the questions individually. I want you to be my eyes and ears
Some points might be something u have to do, like desoldering and cleaning the PCB. If done, post back with a clear picture, it will speed up the process.

First discharge all the caps, shorted the pins of each cap briefly from the underside of the PCB. This will discharge them. Use a tweezer or long nose plier.

1. Label 1 points to the damaged component, it seems to be a chip capacitor, we can be sure at a later stage. for now I want you to remove it. Desolder it, use a your iron or hot gun, be care full not to damage the tracks and near by components. Use plenty of solder and heat. Clean the area with surgical knife or a pointed knife, if necessary, try to scrape off the debris slightly. Use alcohol or thinner to clean the flux residue tht build during desoldering I want you to scrape of the dark debris of that area as much as possible. Try to scrape the green solder mask too, it will help in resoldering process. The way I see it, you have a multi layer PCB. Desoldering could be difficult if the PCB absorbs heat faster than the iron can transfer, in such cases using a big tip with considerable amount of heat would do the job. If you have solder braid or wick. I advise you to use it to clean the burned area.
As you can see the component have burned the PCB upto some extent. scraping off the dark matter and cleaning will tell you how bad the damage is. Being a multi layer PCB, I advise you to be careful not to use force, be gentle, be patient, it will help. clean as much as you can and post a pic, remember to keep removed component, as it tends to get lost in plain sight. Being small and all.

2. I like to confirm whether this component is an inductor or something else, the way I see it, it may be an inductor to filter the ignition in +B. Tell me how many pins it have and what they are connected to. Use the DMM diode range to check for 0Ω.

3. This component is a capacitor, check it's resistance to confirm it is not short circuited.

4. Check this diode for short, if the diode is OK the DMM diode check range should give a reading of around 0.1V or so. These are High current, high speed diodes, which means forward voltage will be lower than a normal diode.. Reverse reading should be there, if u get a reading in reverse remove it and test it, if you can. You might get a reading even if the diode is OK in REVERSE in CIRCUIT, but the reading will increase with in seconds and probably will finally give an over load reading. This is normal. If this occurs diode is OK.

5. No. five shows you two points, I like to know the resistance between them.

6. Same goes for no. six (same as above)

7. No. seven shows two resistors. I want you to trace them through the resistors from the ACC pin to the IC labeled no. 8. Tell me to which pin the ACC is applied. If you can draw out a schema

8. It seems that who ever made this DC to DC converter, did not want any one to find out the parts no. or reverse engineer it. If you can make out the no. it will help. If not, no worries, cause I have a few tricks up my sleeve too. Secondly find the ground pin and the supply pin of this IC, trace it if you can, use 0Ω resistance and check for +B and GND connections. ( since no. is not visible).

9. No. 9 is a continuity check to see to what PIN the inductor (R50_0712) is connected. I don't think u will get a reading. check it.

10. Again since the no. is scraped off I'm thinking that this must be the controller chip for the step down voltages. Just clean the pins and surrounding areas. Use thinner or alcohol and brush off the dirt.

11. and 12 ( notice the no. 4468, familiarize how many of this components are there)
These are the Power MOSFET drivers. The arrow of no. 11 is pointing to the pin 1 of the FET, as u know it counts as a standard 8 pin IC.
But this is a 11A low voltage N CH Power TRENCHFET's. Pin 1 to 3 will give u a short circuit. Pin 5 to 8 will give u a short. This is normal. If you know how to check MOSFET's with a DMM then you can go ahead. pin 1-3 are source, pin 4 is gate, and pin 5-8 are Drain.
The source to drain might give you a short circuit, but that does not mean the FET is shorted. Just check them all. Do not try to remove them. I'll tell you later why they show a short sometimes.
Still I like u to give me the diode readings of all the TrenchFet's. D to S, S to D, D to G, G to D, S to G and G to S.
write them down one by one.

I like to get a scaled picture of both sides of this unit. Equal in focal length and dimension. A high res one. I want to trace out the tracks for further study.

I do hope u understand all these, and I assume, since you have a soldering iron and all and you up to it, that u know the basics of soldering and all. well..u know what I mean.

If in doubt. STOP. and POST BACK...I am here.
PS.. I forgot to ask about the connector near the inductor, what is it?

Happy Hunting
Rifaa

 

I have edited one of the pic and below are the references.
Remember to answer the questions individually. I want you to be my eyes and ears
Some points might be something u have to do, like desoldering and cleaning the PCB. If done, post back with a clear picture, it will speed up the process.

First discharge all the caps, shorted the pins of each cap briefly from the underside of the PCB. This will discharge them. Use a tweezer or long nose plier.

1. Label 1 points to the damaged component, it seems to be a chip capacitor, we can be sure at a later stage. for now I want you to remove it. Desolder it, use a your iron or hot gun, be care full not to damage the tracks and near by components. Use plenty of solder and heat. Clean the area with surgical knife or a pointed knife, if necessary, try to scrape off the debris slightly. Use alcohol or thinner to clean the flux residue tht build during desoldering I want you to scrape of the dark debris of that area as much as possible. Try to scrape the green solder mask too, it will help in resoldering process. The way I see it, you have a multi layer PCB. Desoldering could be difficult if the PCB absorbs heat faster than the iron can transfer, in such cases using a big tip with considerable amount of heat would do the job. If you have solder braid or wick. I advise you to use it to clean the burned area.
As you can see the component have burned the PCB upto some extent. scraping off the dark matter and cleaning will tell you how bad the damage is. Being a multi layer PCB, I advise you to be careful not to use force, be gentle, be patient, it will help. clean as much as you can and post a pic, remember to keep removed component, as it tends to get lost in plain sight. Being small and all.

2. I like to confirm whether this component is an inductor or something else, the way I see it, it may be an inductor to filter the ignition in +B. Tell me how many pins it have and what they are connected to. Use the DMM diode range to check for 0Ω.

3. This component is a capacitor, check it's resistance to confirm it is not short circuited.

4. Check this diode for short, if the diode is OK the DMM diode check range should give a reading of around 0.1V or so. These are High current, high speed diodes, which means forward voltage will be lower than a normal diode.. Reverse reading should be there, if u get a reading in reverse remove it and test it, if you can. You might get a reading even if the diode is OK in REVERSE in CIRCUIT, but the reading will increase with in seconds and probably will finally give an over load reading. This is normal. If this occurs diode is OK.

5. No. five shows you two points, I like to know the resistance between them.

6. Same goes for no. six (same as above)

7. No. seven shows two resistors. I want you to trace them through the resistors from the ACC pin to the IC labeled no. 8. Tell me to which pin the ACC is applied. If you can draw out a schema

8. It seems that who ever made this DC to DC converter, did not want any one to find out the parts no. or reverse engineer it. If you can make out the no. it will help. If not, no worries, cause I have a few tricks up my sleeve too. Secondly find the ground pin and the supply pin of this IC, trace it if you can, use 0Ω resistance and check for +B and GND connections. ( since no. is not visible).

9. No. 9 is a continuity check to see to what PIN the inductor (R50_0712) is connected. I don't think u will get a reading. check it.

10. Again since the no. is scraped off I'm thinking that this must be the controller chip for the step down voltages. Just clean the pins and surrounding areas. Use thinner or alcohol and brush off the dirt.

11. and 12 ( notice the no. 4468, familiarize how many of this components are there)
These are the Power MOSFET drivers. The arrow of no. 11 is pointing to the pin 1 of the FET, as u know it counts as a standard 8 pin IC.
But this is a 11A low voltage N CH Power TRENCHFET's. Pin 1 to 3 will give u a short circuit. Pin 5 to 8 will give u a short. This is normal. If you know how to check MOSFET's with a DMM then you can go ahead. pin 1-3 are source, pin 4 is gate, and pin 5-8 are Drain.
The source to drain might give you a short circuit, but that does not mean the FET is shorted. Just check them all. Do not try to remove them. I'll tell you later why they show a short sometimes.
Still I like u to give me the diode readings of all the TrenchFet's. D to S, S to D, D to G, G to D, S to G and G to S.
write them down one by one.

I like to get a scaled picture of both sides of this unit. Equal in focal length and dimension. A high res one. I want to trace out the tracks for further study.

I do hope u understand all these, and I assume, since you have a soldering iron and all and you up to it, that u know the basics of soldering and all. well..u know what I mean.

If in doubt. STOP. and POST BACK...I am here.
PS.. I forgot to ask about the connector near the inductor, what is it?

Happy Hunting
Rifaa

Hi again Rifaa, and once again thanks for helping

On the end of this afternoon when i arrive home i will try to check all that points, and for now i will answer you what i already know, and i will add an atachment with the manual of this psu to see if it can help any way, the connector near the inductor is a connector to the car amplifier to the cases on which we want the psu to connect and disconnect automaticaly the car stereo amplifier, i think it only sends a switch signal!

regards

 

Hmmm.. interesting.
I thinks the 18 pin IC is a PIC and the surface mount is the switcher.
After reading it I think what I thought was an inductor (no. 2 )...or it could be a fuse.
See if u can find that "blade" fuse thingy.
Take your time and do the above..i'll be back tomorrow....
Haven't slept yet.........yaaaaaaaaaaaawn!!.

Just in case you might be wondering... I'm like PIC programming 24/7. Just started learning em buggers. pretty useful these things are....quite interesting too.
By the way feel free to search for my posts, I am sure u won't get bored.

C ya

Rifaa

 

Hmmm.. interesting.
I thinks the 18 pin IC is a PIC and the surface mount is the switcher.
After reading it I think what I thought was an inductor (no. 2 )...or it could be a fuse.
See if u can find that "blade" fuse thingy.
Take your time and do the above..i'll be back tomorrow....
Haven't slept yet.........yaaaaaaaaaaaawn!!.

Just in case you might be wondering... I'm like PIC programming 24/7. Just started learning em buggers. pretty useful these things are....quite interesting too.
By the way feel free to search for my posts, I am sure u won't get bored.

C ya

Rifaa

One day i would also like to learn how to program a pic, thats in my to do list and i also believe it is possible it's a pic ic, because it has many delay options, so they have to be programed somewhere right?
About the mini blade fuse, it exists on the original m2 atx, but on this chinese clone it doesn't, i think that in the manual it's saying about a mini-blade fuse because it should have been coppied from the original m2 atx manual for sure, because on this one it isn't anywhere, they should have made this simplier instead of harder to work with, but they prefered to make life harder to someone who wanted to fix this for what it looks like

See if you get some rest, you have to take care of yourself my friend! And already read some of your posts, its impressive the way you are always ready to help others, and always have time for helping and the knowledge you have about pretty everything it is needed on this forum!

thanks for letting me be one of the lucky ones that have you as mentor searching for a solution on a problem like this one!

now, go and try to have some rest, and we will speak again tomorrow then!

have a nice sleep!

regards