Help! Help! Help! PSU digital

kyrochan · 23rd November 2007, 06:22 PM

Hallo,
today the digital psu of my Sony dvp-s7700 is dead. Simply when I turn it on the fuse on it blow up.
I've recently replaced the caps before the connector, simply some filter caps on it.
I think the problem is in the trasformer since I don't see any element flamed or burnt.
Do You think I shuold re built a switching PSU or should be better a standar regulated PSU? This PSU feeds evrything in the player except the DAC and the op-amp based output stage.
Ther's the service manual if You want give a look at it.

http://www.eserviceinfo.com/download...DVP-S7700.html

The main problem is that the PSU has several voltage output:
ten output or somthing so.
And could be honestly an hard work repair it. But I have not any idea how to repair this one if as I suspect the trasformer is gone.

Extreme_Boky · 23rd November 2007, 10:19 PM

Do not waste time trying to repair the SMPS, and in the future attempt to modify such power supply only if you know exactly what parts to use to suit high switching frequencies.

The problem is probably related to blown opto-coupler or switching transistor…

I suggest you to obtain the exact replacement SMPS unit from Sony Service. That is, if you want to get the player working again. If your plan is to learn and try everything to repair it yourself, search the “switched mode power supplies” topic on the net and find out the principles of operation first.

Boky

kyrochan · 24th November 2007, 09:23 AM

Please note that I haven't tweak the "switch part" of the psu. Just 4 filter caps at the end of the PSU doubled in value. The only thing that cold be happend is the "stress" of the trasformer for the higher current in the primary. But this is very strange to me.
Anyway, I would like to know if there's a superiority of the Switching psu for Digital psu above standard trasformer/filter/regulating transistor. If I would like to rebuilt the PSU.

23rd November 2007, 06:22 PM	#1
kyrochan diyAudio Member Join Date: Jan 2005 Location: Bari	Help! Help! Help! PSU digital Hallo, today the digital psu of my Sony dvp-s7700 is dead. Simply when I turn it on the fuse on it blow up. I've recently replaced the caps before the connector, simply some filter caps on it. I think the problem is in the trasformer since I don't see any element flamed or burnt. Do You think I shuold re built a switching PSU or should be better a standar regulated PSU? This PSU feeds evrything in the player except the DAC and the op-amp based output stage. Ther's the service manual if You want give a look at it. http://www.eserviceinfo.com/download...DVP-S7700.html The main problem is that the PSU has several voltage output: ten output or somthing so. And could be honestly an hard work repair it. But I have not any idea how to repair this one if as I suspect the trasformer is gone.

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23rd November 2007, 10:19 PM	#2
Extreme_Boky diyAudio Member Join Date: Dec 2003 Location: Sydney	Do not waste time trying to repair the SMPS, and in the future attempt to modify such power supply only if you know exactly what parts to use to suit high switching frequencies. The problem is probably related to blown opto-coupler or switching transistor… I suggest you to obtain the exact replacement SMPS unit from Sony Service. That is, if you want to get the player working again. If your plan is to learn and try everything to repair it yourself, search the “switched mode power supplies” topic on the net and find out the principles of operation first. Boky

24th November 2007, 09:23 AM	#3
kyrochan diyAudio Member Join Date: Jan 2005 Location: Bari	Please note that I haven't tweak the "switch part" of the psu. Just 4 filter caps at the end of the PSU doubled in value. The only thing that cold be happend is the "stress" of the trasformer for the higher current in the primary. But this is very strange to me. Anyway, I would like to know if there's a superiority of the Switching psu for Digital psu above standard trasformer/filter/regulating transistor. If I would like to rebuilt the PSU.