Help finding DIA-002 shorted motherboard

[Ju084]

Hi everyone, i need your help trying to fix my old ps3 cechk-04 with motherboard dia-002.
It was working perfectly fine until 1st of january 2021.
Since this day it doesnt start anymore : i got an instant ylod then blinking rlod....

I found that a lot of component near the rsx chip are shorted. But cannot figure out which one is guilty.

This unit was never reballed, and temperature were very good ( thermal paste changed last year etc.....)

It's 3 weeks I'm investigating but no luck yet. With an external power supply i see that all the voltages are correct i got 12v, 5v, 3.3v and 1.5v. ( half a second until the ylod appears) but i also got 0.6 v from gnd.

Do someone know how to check properly the mosfet, and other component on this line? See attached picture.

Thank for your help!

 

[Ju084]

Also i already removed and test the board without this 3 components, and i still have a short.

The 470uf capacitors are not shorted i already checked too.

 

[haxxxen]

sorry to disturb, but can you make a picture of the nor testpoints on the backside? the area with the lot bunch of testpoints

 

[vyktormvmpay25]

Have you tried UART diagnostic mode for it? It will take less time.

 

[Ju084]

I don't know how to do with UART. What is rhe procedure? I will take a picture of the nor

 

[vyktormvmpay25]

Finding out here
https://r.tapatalk.com/shareLink/to...share_fid=179881&share_type=t&link_source=app
Or here
https://r.tapatalk.com/shareLink/to...share_fid=179881&share_type=t&link_source=app

 

[Ju084]

Finding out here
https://r.tapatalk.com/shareLink/to...share_fid=179881&share_type=t&link_source=app
Or here
https://r.tapatalk.com/shareLink/to...share_fid=179881&share_type=t&link_source=app

If you can help me with the procedure for uart check out find a Tutorial it will be nice. I don't understand what's the necessary material, where to connect the wire on my board, and how to download the error code on a computer?

 

[vyktormvmpay25]

You have usb to rs232 UART adaptor? Your syscon is there on photo. Do you still have that short-circuit on your rsx?

What resistance does it show on power line on tantal caps? It may be mosfet to that line short-circuit but not sure, I will reply more after I remove on dead board. That side of short-circuit on your board should be like 110 ohms or something up from 85.
One more thing to say about measurements on av ic at position with red
If still short on there you can desolder av ic, clean pads so they won't be short-circuited, check again if same measurements.

 

[Ju084]

You have usb to rs232 UART adaptor? Your syscon is there on photo. Do you still have that short-circuit on your rsx?

What resistance does it show on power line on tantal caps? It may be mosfet to that line short-circuit but not sure, I will reply more after I remove on dead board. That side of short-circuit on your board should be like 110 ohms or something up from 85.

Thank you for your help!
Unfortunately i do not have the usb to uart adapter.

The syscon is the ic chip on the other side of the board right?

I still have my short ( same like on my first pictures near the rsx)

I took other values like you asked me ( i hope that's what you asked for?)

1st picture : 111 ohms
2nd. 519 K ohms
3rd. 515K ohms
4th. 123 K ohms

 

[Ju084]

I need first to take the resistance on the red point? And if shorted here you want me to desolder the chip in the white circle and check again for shorts? Am i correct?

I'm scared i can't weld again this chip in a good position as the pitch is really small...

 

[Ju084]

By the way i also have other boards (ylod as well, didn't yet check this ones) and if the problem come from this av chip, can i exchange it with another one from a cechl board?

 

[vyktormvmpay25]

Yes you can exchange it from any motherboard as long is same serial of ic.
What I was point you to take measurements on motherboard only av ic. That syscon is where you solder USB cable to connect pc and do diagnostic test on pc.
Syscon is a system managmet inside hole system right. From here you can see few errors and understand which ic does not have power.
First download from here and read pdf tutorials
https://github.com/db260179/ps3syscon

 

[Ju084]

Yes you can exchange it from any motherboard as long is same serial of ic.
What I was point you to take measurements on motherboard only av ic. That syscon is where you solder USB cable to connect pc and do diagnostic test on pc.
Syscon is a system managmet inside hole system right. From here you can see few errors and understand which ic does not have power.
First download from here and read pdf tutorials
https://github.com/db260179/ps3syscon

Ok, i took the following measures:

On the 2nd and 3rd pictures i got 0 omhs, but on my other board i have 1844 ohms.

 

[Ju084]

To be sure :
- on the first picture it is the av chip
- on second picture it is syscon?

Correct me if i am wrong!

 

[vyktormvmpay25]

Yes. Now have you take measurements on av ic on those points where there is no component soldered? What value do you get there in that place?

Also what value is that capacitor?

Set on resistance should be 320 ohms.

 

[Ju084]

On av ic chip i have 1733 ohms ( see my messages on top)

On the capacitor of your second question i have 312 ohms

 

[vyktormvmpay25]

Seems fine. On bottom of board look at that mosfet and measure caps on his exit or between gnd and that point

So this capacitor is less than 86 ohms?

 

[Ju084]

Here is 0.8 ohms

This one is shorted too, i put it on my first message. I have also 0.8 ohms.

 

[vyktormvmpay25]

If you look on bottom that trace goes under av ic. It is a common trace of that side of rsx and not sure if is with av ic. Could either desolder that mosfet or av ic. Not sure.

It is quite risky with that mosfet. Should have a preheater for boar and heat place until 120°
then with hot air at 300~350 in few seconds should go easy out. You must be careful as you are near rsx. Board should be on a jig or at straight level when you work on it. If you want to desolder av ic first do exact same, preheat board to 120, add flux on pins, add with soldering iron some leaded alloy on all pins which will melt easy then lead free alloy from factory, with hot air 300 ~350 until getting ic out, clean all pads with wick and test again that 0.8 ohms. To be honest never had this issue and not sure how rsx got that side shorted, unless any diode is tied to that power line from hdmi ic

 

[Ju084]

If you look on bottom that trace goes under av ic. It is a common trace of that side of rsx and not sure if is with av ic. Could either desolder that mosfet or av ic. Not sure.

It is quite risky with that mosfet. Should have a preheater for boar and heat place until 120°
then with hot air at 300~350 in few seconds should go easy out. You must be careful as you are near rsx. Board should be on a jig or at straight level when you work on it. If you want to desolder av ic first do exact same, preheat board to 120, add flux on pins, add with soldering iron some leaded alloy on all pins which will melt easy then lead free alloy from factory, with hot air 300 ~350 until getting ic out, clean all pads with wick and test again that 0.8 ohms. To be honest never had this issue and not sure how rsx got that side shorted, unless any diode is tied to that power line from hdmi ic

Thanks a lot for your contribution, i really appreciate it.

I'm at work now and will check this evening.
The short cannot come from the hdmi ic because i already removed it ( i changed it 1 year ago because no hdmi signal, and everything worked again after the change. As i suspected in a first place my maybe not good solder on hdmi ic i removed it but it's not this chip shorted)

I will follow your instructions and remove the mosfet first, i believe it's much easier to sold the mosfet back than the AV IC.....