Author Topic: Zebra/Eltron LP2844 generic power supply  (Read 2053 times)

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Offline StarblazerTopic starter

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Zebra/Eltron LP2844 generic power supply
« on: March 01, 2015, 03:48:11 am »
First off, thanks for the forum and Dave for his videos.

I have a power supply that has failed.  It powers on just fine and prints slowly just fine.  If you select the high speed printing, the printer works just fine until it needs to draw a bit of current.. and then it shuts off and resets.  I replaced the power supply and the problem went away.

I took the old power supply apart and I found the following.  That one part labeled L1(right next to the LED) on the board doesn't look too good.  Additionally, when I measured the two caps next to it.. they measured around 2500uf-3000uf each. 

So, in closing, I think to repair this I need to replace the two caps because they are reading too high.  Does that L1 part look bad? 

Thanks!

 

Offline SeanB

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Re: Zebra/Eltron LP2844 generic power supply
« Reply #1 on: March 01, 2015, 06:26:18 am »
L1 is an inductor, to reduce the noise on the 18V supply to the printer. It is covered with that black shrink cover, and looks fine. If it fails the sleeve will be cooked off it or melted.

Those 2 capacitors will need replacing, though you should also look at the underside and resolder the joints on the secondary rectifier diode, as it will by now be getting a dry joint on the one leg.

A replacement power supply is expensive as OEM, but a cheap laptop power supply ( almost any one, it does not need to supply more than 2A) works well as a replacement.
 

Offline StarblazerTopic starter

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Re: Zebra/Eltron LP2844 generic power supply
« Reply #2 on: March 01, 2015, 08:05:10 am »
Thanks for the reply!  I've taken a peek, a view, and a stare at the bottom of the board and everything else seems to be in order.... well.... for the quality of this PSU.  I'll be sure to resolder those joints though as a precaution while I'm in here.
 

Offline kripton2035

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Re: Zebra/Eltron LP2844 generic power supply
« Reply #3 on: March 01, 2015, 08:37:06 am »
the top cap is beginning bulking. needs a replacement.
may be only this cap is faulty, but the second cap is nothing to replace too so !
the inductor seems fine (by the picture...)
 


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