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HP ZR2440w that won't power up

 
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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.
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vtech



Joined: 08 May 2006
Posts: 1265
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.
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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.
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superman46
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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
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NoName234
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PostPosted: Wed Oct 16, 2013 6:21 pm    Post subject: Reply with quote

Same here, anything new?
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velip
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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.
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velip
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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.
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Jason123
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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.
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