Call help ... My Advantest R3271 canot boot after I changed all E-CAPs

[williamlee]

Hi all,
  My Advantest R3271 cannot boot after I changed all E-CAPs of PSUs(2 BOARDS). Because of smell BBQ ...  so, I decided to open it. What I found is that 60% E-Cap has leaking.
But after E-caps changed, I put the 2 PSU back and turned the power on, I only saw the buttons light around half sound ... and then, everything is quiet, no display, smoke, and explode. 
  Can any clue to me? Thanks a lot

[squadchannel]

Troubleshoot the power supply on its own.
whether voltage is normally present on each power line when run by itself.

 

[coppercone2]

more then likely you disturbed a very damaged trace when replacing the caps that took it out totally.

[williamlee]

No display and no boot activity(buttons led just light within 0.2 second ) . I tried to test each power line and it's totally not normal -// really sad, especially for a beginner like me. I am sure that the capacitor change is okay. (I did ifr 1200s)

[williamlee]

I was careful and used HOKKO FR-301 for the desoldering job. 

[williamlee]

Did anyone know what the number can replace this "Diode"?

[squadchannel]

I checked the manual, but there is no schematic of the power supply section.

first to see if there is any visible damage in board. I don't see how the diode could be damaged.

You said "totally not normal".
In detail, which power supply lane is wrong? all supply lanes wrong?

Did the smoke come from the power supply board? Isn't it from RIFA cap?

Is power supplied to the PWM control IC? Are safety devices such as thermistors functioning properly?

First, check if there is no short on the AC side DC side of the full bridge rectifier, if the winding of the switching transformer is normal, and if the FET is normal.

[wasedadoc]

Did the smoke come from the power supply board? Isn't it from RIFA cap?

I think the "and" in the OP's "everything is quiet, no display, smoke, and explode." should have been "or".

[lowimpedance]

You have checked carefully that no damage/corrosion to adjacent components or PCB traces occurred near the leaking capacitors ?
Have you put it back together correctly !

Why those two diodes ? , do they measure short as that might be in circuit paths giving incorrect measurement.
What fuses are there if any besides the obvious mains in. Are they all good !

Some overall pictures would be helpful too.

[williamlee]

Thank you, the without schematics is a big issue. My feeling is ... when I turn on the power, everything is quiet after all the button LED lights just flash 1 time, even the fan is stop there ( 1 pin is 11.2v, the other one is 11.4v) I try to check what you mentioned.   

[williamlee]

I cannot find the RIFA, but the universal switching unit seems fine, it generates AC118v almost the same as the input.   

[williamlee]

The circle of red are leaking area, I did test it several times. All new e-cap was been tested by DEREE DE-5000.

[williamlee]

No schematis is big issue. Advantest should doing something.

[williamlee]

Some resistors damage near around M51995P.

[squadchannel]

https://www.seti.net/notebook/volume-11/chap69/R3271_PSU.zip

I found a little bit of information. It looks like a block diagram and delivery documents.
It shows the secondary side circuit.

[williamlee]

Today, I checked all 1/16w resistors on the second PSU and found 47 pcs were gone. a lot of the 10k, 7.5k. So, tired 

[_rushin_or_draggin_]

Just to clarify, before you replaced all the electrolytics, was the unit functioning properly? You may want to double check and make sure none of the caps are backwards (although I’m sure an audible pop would’ve let you know already). Do a very thorough inspection of all the traces and components in the areas you were working. Try to, with the board powered off, trace the paths as far as you can to make sure something doesn’t have a cold solder joint. Check for shorts as well like already stated. If you power the board up out of circuit and you get all the correct voltages, then you’re going to have to dig deeper. Unfortunately, until some schematics are found, it’s going to be rather difficult I think.

[williamlee]

Thank you for your suggestion. It function worked fine before I did Caps replacement. I am waiting for some components for replacement. But the worst case is to rebuild a new power unit for it.

[williamlee]

Attached is why I make the decision for all Caps replacement.

[Haenk]

Attached is why I make the decision for all Caps replacement.

That seems very reasonable by the looks of it.

[_rushin_or_draggin_]

I definitely agree with your decision to replace them. It just seems odd that it worked with all that leakage and then stopped when they were replaced. I agree with what coppercone2 said about the possibility of disturbing an already damaged trace. It might be beneficial to ohm out all traces and see if you get lucky. That or wait for your parts to get in and go from there. What parts are you planning on swapping out exactly?

[williamlee]

Most order parts arrived, C1093, MB3769A, UPC209C, C330C, M51995AP, MB3769A. Hope, everything will be fine