electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
ATX power suply LC8700 doesn't work (+5V) ICs PS229 and wt75
Goto page 1, 2  Next
 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Service manuals & datasheets
View previous topic :: View next topic  
Author Message
dr.1m



Joined: 30 Jul 2008
Posts: 6
Location: SI

PostPosted: Wed Jul 30, 2008 12:38 pm    Post subject: ATX power suply LC8700 doesn't work (+5V) ICs PS229 and wt75 Reply with quote

I searching for datasheet of this two IC but till now I have no luck.
The two IC are:
1st one is 8pin with this marking
Weltrend
WT7518D 636
2nd one is 14pin with this marking
PS229
M05B24A1F

Have anyone more luck? Here is the photo of this two ICs.
Back to top
View user's profile Send private message
vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Fri Aug 01, 2008 5:29 am    Post subject: Reply with quote

Your best bet is to try checking the electrolytics first or "try" getting a schematic which is more likely impossible? This is why I hate having to deal with chinese made yingyang crap who choose not to have any information whatsoever.
The weltrend number alone refers to a 14 pin dip? perhaps a 8pin version made just for them? and the other one is simply non-existant--even the logo seems obscure.
Back to top
View user's profile Send private message
dr.1m



Joined: 30 Jul 2008
Posts: 6
Location: SI

PostPosted: Wed Aug 06, 2008 7:58 am    Post subject: Reply with quote

vtech thank you.
Till now I find only the datasheet for Weltrend IC but nothing for other one.
The problem I have is that the 5V output don't work properly. In fact the 5V output is OK till is unburdened (without load), but the PS switch if instantaneous when I connect the load.
I checked the capacitors of 5V output and also change them, but nothing change. The interesting think is that if I connect the load before switch PS on the PS work (after switch it on) for couple of second an the switch off. In that time the 5V output is little under run:
With current around 3A the voltmeter indicate 4,9V and is litle waved.
With current around 25A the voltmeter indicate 4V and is more waved.
But with 1A load the voltage is good.
Back to top
View user's profile Send private message
dr.1m



Joined: 30 Jul 2008
Posts: 6
Location: SI

PostPosted: Thu Sep 25, 2008 7:00 am    Post subject: Reply with quote

Until now I haven't found any deflects. Probably is that the power supply is good, and I'm trying it in a wrong way. Why?
I know that the ATX power supply work only if they have a load on 5V output, but here it seems that not so. Why?
When on the output of 12V is a load that consumes 1A the 5V voltage output is stable. At least until 12A.
It's possible that the power supply has working conditions other than the standard ATX. It means that it's run only if there is a load placed on 12V output instead of 5V output? Rolling Eyes
Back to top
View user's profile Send private message
Guest






PostPosted: Sun Oct 25, 2009 1:52 am    Post subject: Reply with quote

did you found solution for your problem, because I have the same problem with my PSU lc8850 :S
Back to top
dr.1m



Joined: 30 Jul 2008
Posts: 6
Location: SI

PostPosted: Mon Oct 26, 2009 1:02 pm    Post subject: Reply with quote

And what is your problem with it, anyway?
I found that maybe the my PS doesn't have any problem, but I didn't tested it on new PC yet.
Back to top
View user's profile Send private message
Guest






PostPosted: Mon Oct 26, 2009 1:54 pm    Post subject: Reply with quote

I dont have stable 5 and 3.3v but when on the output of 12V is a load that consumes 1A the 5V voltage output is stable, but the bigest problem is schematic for this kind of PSU because I can't find any :S
Back to top
dr.1m



Joined: 30 Jul 2008
Posts: 6
Location: SI

PostPosted: Mon Oct 26, 2009 2:27 pm    Post subject: Reply with quote

Even I didn't find any schematic. Anyway, I don't aspect it any more.
Did you understand my answer? Do you use it on a new PC? Because it seem that it can't work on oldest PC.
Back to top
View user's profile Send private message
Guest






PostPosted: Tue Oct 27, 2009 9:31 am    Post subject: Reply with quote

yes I understand, but it worked on my pc before and now same psu wont start computer :S
Back to top
Guest






PostPosted: Tue Oct 27, 2009 4:58 pm    Post subject: Reply with quote

Aha, now I see... but I don't know the solution. Maybe I have the same problem... I will see.
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Service manuals & datasheets All times are GMT
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Електроника София - Service Manuals Free Download - Prikachi - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Search - Jabse.InK  - Pulsator

Connector Pinout Forum - Новини - SnimkiOt.com - безплатен DNS - Whois разузнаване - Poblizo.com : пътешествия