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Electronics => Repair => Topic started by: negativ3 on September 21, 2017, 01:01:37 am

Title: Dell 19" monitor standby
Post by: negativ3 on September 21, 2017, 01:01:37 am
Hi all,

Had a strange occurrance with a monitor. Left the PC rendering overnight and made sure all monitors were in standby.

The Dell standby was off (power button light out), indicating no power, so I removed the power cable and re-inserted it, with the same result.

When inserting the cable, I heard the "crackle" of electricity as the contacts mated.

I unplugged the monitor again, and left it for 10 minutes, after which I plugged it back in and it works.

Is this some kind of protection or am I seeing the start of a failure in the PSU? The PSU is internal to the monitor.

Put it back into service and wait until it fails, Dave? :)

Thank you.
Andy
Title: Re: Dell 17" monitor standby
Post by: Toasty on September 21, 2017, 01:08:32 am
There are many monitors.  May we have a model number?  How old is the unit?

T
Title: Re: Dell 19" monitor standby
Post by: negativ3 on September 21, 2017, 01:40:27 am
My apologies, it's an Ultrasharp 1905FP, at least a decade old.
Title: Re: Dell 17" monitor standby
Post by: Toasty on September 21, 2017, 01:54:50 am
Thanks!

Common issue as you correctly assumed, the PSU.  Specifically the capacitors from that era were particularly bad.  I'm amazed it lasted this long...

Recap is fairly easy and inexpensive.

Parts:

Code: [Select]
Dell 1905FP

[ Max cap height 22mm ]

3 - 1000@10v  - 10x16 - Capxon KF  -  Pana FM == P12353-ND - EEU-FM1A102
1 - 1000@25v  - 12x16 - Capxon KF  -  Pana FM == P12379-ND - EEU-FM1E102
1 - 2.2@50v   - 5x11  - Capxon KM  -  Pana FC == P10313-ND - EEU-FC1H2R2
1 - 4.7@50v   - 5x11  - Su'scon    -  Pana FC == P10315-ND - EEU-FC1H4R7
1 - 10@50v    - 5x11  - Capxon KM  -  UCC KZE 5x7 == 565-1702-ND - EKZE500ELL100ME07D
1 - 22@50v    - 5x11  - Capxon KM  -  Pana FM == P12927-ND - EEU-FM1H220
2 - 220@50v   - 10x16 - Capxon KM  -  Pana FM == P12397-ND - EEU-FM1H221
4 - 470@35v   - 13x20 - Capxon KF  -  Pana FM @ 50v == P12400-ND - EEU-FM1H471
    {Sub for FM - UCC KZE == 565-1712-ND - EKZE500ELL471MK20S}
1 - 150@450v  - 18x45 - UCC PAG    -  Not Replaced; not a common failure

-------
15 caps - 14 replaced

** Note: The FM series from Panasonic has been somewhat deprecated starting 2 years ago.  Replacements are in the FR series.

Also, while you're in there, redo the solder on pins of the 2 transformers for the backlights.  Known to be a source of problems from poor or cracked connections.

T
Title: Re: Dell 19" monitor standby
Post by: negativ3 on September 21, 2017, 02:33:23 am
All I can say Toasty is thanks very much, I will get the parts on the way and look at the backlight transformers for sure.

Will update again when all done.
Title: Re: Dell 19" monitor standby
Post by: Bushougoma on September 23, 2017, 12:50:40 pm
That crackle could have been arcing due to cracked solder joints on the IEC connector check those too when you open it up.
Title: Re: Dell 19" monitor standby
Post by: negativ3 on September 28, 2017, 07:57:11 am
Very good point, I will give it a full health check when the bits arrive.