electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
HP ZR2440w that won't power up

 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Computer and office equipment repairs
View previous topic :: View next topic  
Author Message
lelleprinter82



Joined: 28 Jan 2013
Posts: 2
Location: Linkoping, Sweden

PostPosted: Mon Jan 28, 2013 6:46 pm    Post subject: HP ZR2440w that won't power up Reply with quote

Hi everyone.

I've tried to repair an HP ZR2440w lcd monitor that won't power up.
I've rescued it from the dumpster. Of course it was standing outside, so th eunit was cold. So I let it stand for a few hours in room temperature, before powering it on. It powered up that day, but the next day it was completely dead. :O It won't power up anymore, so I took it apart to look for any bad caps. I couldn't find any, but I replaced the ripple capacitor + two on the secondary side. Still won't power up. I was getting voltages on the primary side, but not on the secondary side. There were no voltages after the little transformer between the primary and secondary side. (TPW-E910) Li Tai.
These Output voltages are mentioned on the power supply:
+5v/3.0A
+12V/0.7A
+65V/0.48A
I was getting zero voltage, it refuses to power up. So I suspect the little transformer. But I cannot find any information on the internet at all about the transformer, not even about the Power Supply. (Tatung TPC-06034)

Maybe someone can shed some light, as I'm out of ideas. The monitor is in a very good condition, no cracks or what so ever. So it would be a shame to throw it away. It still costs 3200 SEK in stores. (about 500 dollars or 370 euro)

I have some photos of the power supply, even the underside of it.
And the model number, if anyone want's to see the photos.

Sorry if my english is bad, I'm from sweden. I've explained as good as I could.
_________________
I love electronics and computers, and I love to repair it too.
Back to top
View user's profile Send private message MSN Messenger
vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Tue Jan 29, 2013 1:22 am    Post subject: Reply with quote

Without some sort of a schematic it is hard to tell. I'd say chances of the transformer being the problem is vey unlikely? You could always check the transformer for continuity? There is always a switching power supply involved and a slight problem can prevent it from running all together.
Just about all you can do is to look for things like open resistor(s) or may be even a dead short on any of the power supply lines?
While I am not familiar wit the specific monitor, I used to repair monitors and bad caps & shorted diodes were rather common.
Back to top
View user's profile Send private message
lelleprinter82



Joined: 28 Jan 2013
Posts: 2
Location: Linkoping, Sweden

PostPosted: Tue Jan 29, 2013 10:05 am    Post subject: Reply with quote

Hi, and thanks for your answer.

I will check for shorted diodes, the primary part seems to be ok.
But I'll check for shorts etc.

I'll inform you after this.
_________________
I love electronics and computers, and I love to repair it too.
Back to top
View user's profile Send private message MSN Messenger
superman46
Guest





PostPosted: Tue Apr 02, 2013 7:50 am    Post subject: Reply with quote

Hello!

Did you manage to repair it?

I have same problem =)

Regards, Bojan
Back to top
NoName234
Guest





PostPosted: Wed Oct 16, 2013 6:21 pm    Post subject: Reply with quote

Same here, anything new?
Back to top
velip
Guest





PostPosted: Tue Jan 05, 2016 6:32 am    Post subject: Reply with quote

Hi,

I found this thread by Google. I was able to repair my ZR2440w. I didn't power up with power button (nothing happened) and had no voltages on secondary side.

It got faulty resistor on switch mode controller bootstrap circuit on primary side. Faulty one was R810 that is 4.7MOhm. It seems to have three resistor in series so it would be good to check all of those. I used two 5MOhm 1000V resistors in series for R810. Now the display works fine.
Back to top
velip
Guest





PostPosted: Tue Jan 19, 2016 6:59 am    Post subject: Reply with quote

Sorry, I don't know what I was thinking when writing last reply but I was used two 10MOhm resistors in parallel of course.
Back to top
Jason123
Guest





PostPosted: Mon Jun 12, 2017 1:02 am    Post subject: Thanks Reply with quote

Thanks buddy.. R810 was dead on mine too.. thanks for saving me hours of troubleshooting.
Back to top
AeroLars
Guest





PostPosted: Sun Jan 27, 2019 2:04 pm    Post subject: Reply with quote

many thanks for this information.
Here ist was R813, Also 4,7MOhm.
Best regards Lars
Back to top
Guest






PostPosted: Sat Mar 09, 2019 12:13 am    Post subject: Reply with quote

R813 here also. Used an AB 1/2W 4.7Mohm carbon resistor

Thanks so much for information that kept the required repair time low enough to make this repair worthwhile.
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Computer and office equipment repairs All times are GMT
Page 1 of 1

 
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


eServiceInfo on FB - Service Manuals Free Download - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Service Manual Search - Jabse.InK  - onTap.bg

SnimkiOt.com - Poblizo.com : пътешествия