Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

My Dell 2000FP 20" TFT has some problem with the control circuits. It
started out as a temperature-related problem - if the monitor had been
switched on for say 30 mins and I switched it off and then on again, it
would get stuck in its boot-sequence or lock in standby mode. Ok again
after cooling down.

Recently (as I guess is expected) it stopped working and is now always
in this "half-booted" mode with the power LED lit as if in standby
mode.
Anyway, after some phone calls I discovered that Dell doesn't repair
monitors, and neither do the generic repair companies ("we don't have a
service agreement with Dell or with Dell parts").

So, I have now opened the monitor up myself looking for evident stuff
like burned caps and such - none found, but yeees there are many chips
and micro-components in there! But while doing this I saw that several
of the circuit boards are branded Acer.

My question to you pros is what would be my best shot; trying to find
an Acer technician, try to find Acer parts and replace boards myself,
bin the monitor, ...?

Cheers
Mike

  #2   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

Maybe try a can of component cooler on parts until you find the
part/area that is faulty. My $0.02.

-Brian

  #3   Report Post  
Posted to sci.electronics.repair
JANA
 
Posts: n/a
Default tft always in standby mode

In these monitors I have been sometimes lucky and found capacitors reading
high in ESR. You will need an ESR meter to test them. You can purchase SMD
type capacitors from most of the major electronics parts suppliers. You will
need a proper soldering iron and good soldering skills to change any of
these caps.

Farther than that, would not be possible do service at home. The warranty
service people change the boards to fix these monitors.

--

JANA
_____


wrote in message
oups.com...
My Dell 2000FP 20" TFT has some problem with the control circuits. It
started out as a temperature-related problem - if the monitor had been
switched on for say 30 mins and I switched it off and then on again, it
would get stuck in its boot-sequence or lock in standby mode. Ok again
after cooling down.

Recently (as I guess is expected) it stopped working and is now always
in this "half-booted" mode with the power LED lit as if in standby
mode.
Anyway, after some phone calls I discovered that Dell doesn't repair
monitors, and neither do the generic repair companies ("we don't have a
service agreement with Dell or with Dell parts").

So, I have now opened the monitor up myself looking for evident stuff
like burned caps and such - none found, but yeees there are many chips
and micro-components in there! But while doing this I saw that several
of the circuit boards are branded Acer.

My question to you pros is what would be my best shot; trying to find
an Acer technician, try to find Acer parts and replace boards myself,
bin the monitor, ...?

Cheers
Mike


  #4   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

Hi Brian, the monitor doesn't function even when cool any longer, but
you reckon that the broken component will function if made really cool?
(I might start with putting the monitor outside for an hour or so, only
+5C here ;-)
Any suggestions on which components are usually temp related and which
are not (to avoid unnecessary tests)? Chips, caps, ...?
Thanks/Mike

  #5   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

Hi JANA,

In these monitors I have been sometimes lucky and found capacitors reading
high in ESR.


Ok, sounds interesting. And have you seen this on monitors with the
kind of problems I'm having? (Ie, is a broken cap a probable cause?)

Farther than that, would not be possible do service at home. The warranty
service people change the boards to fix these monitors.


Well, that was one of the tricky parts as Dell doesn't sell parts for
their monitors, not to anyone. Is it easier to get parts for Acer
monitors and/or can I assume that my Dell monitor is an Acer design
from top to bottom, or did Acer just produce the boards according to
Dell specs...?

Thanks/Mike



  #6   Report Post  
Posted to sci.electronics.repair
JANA
 
Posts: n/a
Default tft always in standby mode

I cannot answer the question about the product relationship between DELL and
Acer. I know that DELL subcontracts to many of the big monitor manufactures
for their monitors, as like all their other devices. DELL themselves are not
a manufacture.

I found that with all these computer monitors, it is almost impossible to
buy original parts or service manuals for them.

The most common cause of failures with these monitors are capacitors going
high in ESR. The surface mount capacitors are available from Digikey, and
other suppliers like them. You will have to know the size number, the
microfarads, and the voltage rating of the ones you need in order to place
an order. Or, you can get their catalogue, and try to identify the
capacitors yourself.

If the monitor is used with defective caps, eventually this may lead to
other failures. Also, with age other types of components can start failing,
which leads to an unreliability factor after some time.

As for most of the IC's and non generic types of components in these
monitors, they will be impossible to purchase from any of the electronics
parts suppliers. The manufactures of these components will not sell directly
to anyone who is not the contractor who made the original purchase.

The manufactures of these monitors do not service any of their monitors at
the component level. They put in new boards, and then re-calibrate using an
interface system that connects to the monitor.

After warranty, most of these monitors do not pay to service, unless it is a
high end monitor that is very costly to replace.


--

JANA
_____


wrote in message
oups.com...
Hi JANA,

In these monitors I have been sometimes lucky and found capacitors reading
high in ESR.


Ok, sounds interesting. And have you seen this on monitors with the
kind of problems I'm having? (Ie, is a broken cap a probable cause?)

Farther than that, would not be possible do service at home. The warranty
service people change the boards to fix these monitors.


Well, that was one of the tricky parts as Dell doesn't sell parts for
their monitors, not to anyone. Is it easier to get parts for Acer
monitors and/or can I assume that my Dell monitor is an Acer design
from top to bottom, or did Acer just produce the boards according to
Dell specs...?

Thanks/Mike


  #7   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

Thanks for your detailed reply JANA!

The most common cause of failures with these monitors are capacitors going
high in ESR.


Well that sounds promising!

After warranty, most of these monitors do not pay to service, unless it is a
high end monitor that is very costly to replace.


An equivalent monitor is priced from around $600. Do you have any idea
in what price range a replacement board would be, in case I would find
a match among Acer's parts?
(So I don't waste time looking for a part that will be too expensive
anyway...)

Cheers
Mike

  #8   Report Post  
Posted to sci.electronics.repair
Dave
 
Posts: n/a
Default tft always in standby mode

wrote in message
ups.com...
Thanks for your detailed reply JANA!

The most common cause of failures with these monitors are capacitors
going
high in ESR.


Well that sounds promising!

After warranty, most of these monitors do not pay to service, unless it
is a
high end monitor that is very costly to replace.


An equivalent monitor is priced from around $600. Do you have any idea
in what price range a replacement board would be, in case I would find
a match among Acer's parts?
(So I don't waste time looking for a part that will be too expensive
anyway...)

Cheers
Mike

For boards, lcdpart.com sells inverter boards and Norris Parts on eBay sells
logic boards. I've worked with them and they are both pretty solid. If I
were in your shoes, I'd buy a working cracked screen monitor of the same
model on eBay and swap in the good boards. I've purchased cracked screen
monitors for as low as $15 just to get the working boards and the backlite
bulbs.

Maybe its just a coincidence but I'm starting to see a number of 2000fp's on
eBay that just "died" or have other circuit related problems. That might be
a signal to stock up on boards or to just trade up to something newer. Or
it might not. ;-)

Dave


  #9   Report Post  
Posted to sci.electronics.repair
 
Posts: n/a
Default tft always in standby mode

Stick it in your freezer for at least 12 hours, see if it comes up OK.
If not, toss it. If it does, ;-) , just don't turn it off.


Actually not a bad idea. Just for curiosity; why such a long time? (I
just looove scientific explanations ;-).

  #10   Report Post  
Posted to sci.electronics.repair
Kevin G. Rhoads
 
Posts: n/a
Default tft always in standby mode

Just for curiosity; why such a long time

If it is, as the other posts suggest, high leakage electrolytics, then you want the electrolytics'
electrolyte paste to be completely chilled. Since this is aqueous, dense paste it has a relatively
high heat capacity and at best only moderate heat conductance. 12 hours is usually ong enough to
complete freeze chicken pieces, so it should be more than adequate for electrolytics, none of which
in such a device should be as big as chicken parts. Now if it were old DEC power supplies, for example,
I'd suggest longer, they often had electrolytics as big or bigger than a 40mm round, which would have
longer characteristic cooling times.
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Preventing TV standby mode [email protected] Electronics Repair 7 January 4th 06 08:23 AM
Pimp my scale or:The YADRO-Files, part 1 Nick Müller Metalworking 6 September 17th 05 12:17 AM
standby mode consumption vs longevity Sam Electronics Repair 3 October 23rd 04 05:09 AM
Are PC surge protectors needed in the UK? greywolf42 Electronics Repair 82 July 13th 04 11:37 AM
RCA TV CTC169 (BG5) F35750ST Wont come out of standby - Ticking sound when Power button is pressed Electronics Repair 0 September 25th 03 06:25 PM


All times are GMT +1. The time now is 06:48 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"