Re: Sony DA0HK5MB6F0 MBX-269 problem

Thanks for suggesting openboardview.[B]org[/B]
Board looks like a little bit different but I could find PR498 and PR499. They both are on the board.Re: Sony DA0HK5MB6F0 MBX-269 problem

Thanks for suggesting openboardview.[B]org[/B]
Board looks like a little bit different but I could find PR498 and PR499. They both are on the board.Re: Sony DA0HK5MB6F0 MBX-269 problem

Thanks for suggesting openboardview.[B]org[/B]
Board looks like a little bit different but I could find PR498 and PR499.

Re: Sony DA0HK5MB6F0 MBX-269 problem

High-side MOSFET seems to be ok. All componnets in the feedback circuits seem also to be ok. I can not find PR498 and PR499 in vicinity of PU105.
I downloaded also .brd file but I can not open it in Eagle v9 or v6.
I am getting "Error: line 1, column 1: Start tag expected."

So, I really can not find the resistors

Edit:
Hmm, it seems that PC496 is not present. I don't know, maybe I removed it with hot-gun while replacing PQ253.
What is this TONSEL signal? PC496 and PR374 build a RC...

Re: Sony DA0HK5MB6F0 MBX-269 problem

Ok, I was able to measure (or not measure) gate frequencies. My multimeter has also frequency measurement mode. When I measure other MOSFETs' gate, I can read some frequencies.
When I measure gates of PQ252 & PQ253, there is no signal.
So, that means PU105 is damaged?
Where can I find it?

Re: Sony DA0HK5MB6F0 MBX-269 problem



Thanks for answer.
There is only one enable signal at PU105, pin 15. When I press power button enable signal is 3V. TON signal (pin 16) is 1V. Power supply for IC is 5V at pin 2.
Output resistance is around 12 ohm. I measured it at PC493.
Can I measure gate frequencies with multimeter? Is it DC and square wave?...

Hi,

I have a DA0HK5MB6F0 MBX-269 motherboard and it is not working. I have schematics and I checked all power supplies and found out that 1.05V 15A PS controlled by PU105 was not working. I checked MOSFETS PQ252 & PQ253 and PQ253 was damaged. I replaced it but still PU105 is not producing 1.05V.
When I press power button, 3 LEDS LED_NUM1, LED_CAP1, LED_SCR1 are lighting and orange LED D13 (SATA_ACT) is lightning for 2-3 seconds. Then it powers down again.
On screen there is nothing.

What is the problem? I don't have any EEPROM programmer.
...

Re: Unitrend UT61E (pictures included)

I have a question. Is it possible to measure hFE of a trasnsistor with the UT61E? I know it is possible with other models but UT61E does not have any hFE measurement option. How can we measure hFE even there is no hFE measurement on it?

Re: New Members - please post your introductions here

Hi all,
I am new member here and I would like to introduce myself. I am an electrical engineering student and I am doing my master degree in the area of computer hardware and automation.

Thanks a lot.