Repair SMPS - Need help identifying SMD, schematic attached

silversweden · 23rd December 2008, 11:01 PM

Hello folks!
I need some help identifying a SMD transistor. Q119 on schematic.
Schematic of SMPS on Page 129 and 131. www.itxpress.se/433cmx.pdf

It says "YA" on top of the SMD transistor Q119.
And it is a SOT23 package or similar.
It should be a FET according to schematic.

On most sites i find that YA is a pnp wich is faulty according to schematic.

But then i found this site:
http://www.ginko.de/user/franz.hambe...mdcode/cy.html

It says YAs = BSS83P wich is a SIPMOS, could this be correct?
Maybe i can use BSS84? Dont know if this part is critical.

The reason i want to replace it is because it reads a low Ohm.
R133 are burnt and Q125 shorted, probably because Q119
failed. Anyone who can confirm or dismiss my theory?

Any help here would be great though!

scott wurcer · 23rd December 2008, 11:12 PM

You need to ID the maker, AFAIK the codes are only unique within one companies product line and should be on their datasheet. With some really tiny packages the ID is only on the strip carrier or shipping bag so you need the schematic.

silversweden · 23rd December 2008, 11:36 PM

I posted a link to the schematic. It does not say what they are.
Just a schematic. I think pioneer bought the power board
from someone else to power PDP. All components on the
other schematics for the different boards is written out.

But not the Power Supply

What should i do?

Lumba Ogir · 24th December 2008, 12:47 AM

silversweden,
BSS83P and BSS84 are PMOS. You need NMOS.

silversweden · 24th December 2008, 01:26 AM

I really cant find the original part number

Wich NMOS could i replace this with?

Lumba Ogir · 24th December 2008, 02:15 AM

silversweden,
I don`t think a part number exists. YA is probably just some kind of internal designation or production code.
Try some NMOS you can get.

silversweden · 24th December 2008, 02:30 AM

Yippie! I found it =) i think. on this site, dont understand the language.
http://monitor.net.ru/forum/plasma-p...fo-114977.html

just saw what YA = 3LN01C wich is a NMOS

maybe they just suggested that part... dont know

Lumba Ogir · 24th December 2008, 02:46 AM

That`s a real audiophile-grade device.

silversweden · 24th December 2008, 02:51 AM

okey but do you think it will work?

Lumba Ogir · 24th December 2008, 03:09 AM

It definitely will. My assumption was wrong, the marking is confirmed in the datasheet. It`s the device.

23rd December 2008, 11:01 PM	#1
silversweden diyAudio Member Join Date: Oct 2007	Repair SMPS - Need help identifying SMD, schematic attached Hello folks! I need some help identifying a SMD transistor. Q119 on schematic. Schematic of SMPS on Page 129 and 131. www.itxpress.se/433cmx.pdf It says "YA" on top of the SMD transistor Q119. And it is a SOT23 package or similar. It should be a FET according to schematic. On most sites i find that YA is a pnp wich is faulty according to schematic. But then i found this site: http://www.ginko.de/user/franz.hambe...mdcode/cy.html It says YAs = BSS83P wich is a SIPMOS, could this be correct? Maybe i can use BSS84? Dont know if this part is critical. The reason i want to replace it is because it reads a low Ohm. R133 are burnt and Q125 shorted, probably because Q119 failed. Anyone who can confirm or dismiss my theory? Any help here would be great though!

23rd December 2008, 11:12 PM	#2
scott wurcer diyAudio Member Join Date: Jan 2004 Location: cambridge ma	You need to ID the maker, AFAIK the codes are only unique within one companies product line and should be on their datasheet. With some really tiny packages the ID is only on the strip carrier or shipping bag so you need the schematic. __________________ 2012, our time is running out.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
SMPS repair has me stumped	PM650	Power Supplies	3	19th January 2009 09:56 PM
Nad 218 THX repair/faulty/schematic/etc	IsakAlexander	Solid State	0	27th July 2008 03:52 PM
Anyone ever repair the smps inside an Alpine V-Drive head unit?	turbo_slug	Car Audio	1	18th March 2008 08:42 PM
Capacitor choice for attached schematic	kasra	Tubes / Valves	11	17th February 2007 06:46 PM
Car poweramp SMPS repair TL594CN based design, help!	Puggie	Power Supplies	3	2nd August 2006 08:21 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

23rd December 2008, 11:36 PM	#3
silversweden diyAudio Member Join Date: Oct 2007	I posted a link to the schematic. It does not say what they are. Just a schematic. I think pioneer bought the power board from someone else to power PDP. All components on the other schematics for the different boards is written out. But not the Power Supply What should i do?

24th December 2008, 12:47 AM	#4
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	silversweden, BSS83P and BSS84 are PMOS. You need NMOS.

24th December 2008, 01:26 AM	#5
silversweden diyAudio Member Join Date: Oct 2007	I really cant find the original part number Wich NMOS could i replace this with?

24th December 2008, 02:15 AM	#6
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	silversweden, I don`t think a part number exists. YA is probably just some kind of internal designation or production code. Try some NMOS you can get.

24th December 2008, 02:30 AM	#7
silversweden diyAudio Member Join Date: Oct 2007	Yippie! I found it =) i think. on this site, dont understand the language. http://monitor.net.ru/forum/plasma-p...fo-114977.html just saw what YA = 3LN01C wich is a NMOS maybe they just suggested that part... dont know

24th December 2008, 02:46 AM	#8
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	That`s a real audiophile-grade device.

24th December 2008, 02:51 AM	#9
silversweden diyAudio Member Join Date: Oct 2007	okey but do you think it will work?

24th December 2008, 03:09 AM	#10
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	It definitely will. My assumption was wrong, the marking is confirmed in the datasheet. It`s the device.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)