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  
Reinhard
 
Posts: n/a
Default No horizontal sweep on NEC FE1250

Hi,

I've got a NEC FE1250 (JC22W71) 22" monitor which display a vertical line only. This is
due to a blown R556. The point is I can't figure out why this resistor keeps on blowing.
There is a service bulletin from NEC that states:

The result of cause investigation to which R556 becomes open, it turns out that IC541
which is power regulator for IC501 is operating incorrectly. It is thought that IC541 has
received damage, point of bonding wire inside of IC has stress with over heat or abnormal
welding conditions.

I replaced the parts as described in the bulletin, but the results so far are that the
monitor will operate ok for a while, but then R556 blows again.

Any suggestions are welcome.

Thanks,
Reinhard


  #2   Report Post  
Jerry G.
 
Posts: n/a
Default

It can be that the IC is being damaged from something, and thus blowing the
resistor. Check to see if the main power supply is in specs. If it is over
voltage this can cause the problem you are having. Also, if something is
pulling too much current on the load side of the resistor, it will be
damaged, including other components in the path of the load. In simple
terms, you will have to replace the damaged parts, and also look for the
cause of these failures.

--

Jerry G.
==========================


"Reinhard" wrote in message
...
Hi,

I've got a NEC FE1250 (JC22W71) 22" monitor which display a vertical line
only. This is
due to a blown R556. The point is I can't figure out why this resistor keeps
on blowing.
There is a service bulletin from NEC that states:

The result of cause investigation to which R556 becomes open, it turns out
that IC541
which is power regulator for IC501 is operating incorrectly. It is thought
that IC541 has
received damage, point of bonding wire inside of IC has stress with over
heat or abnormal
welding conditions.

I replaced the parts as described in the bulletin, but the results so far
are that the
monitor will operate ok for a while, but then R556 blows again.

Any suggestions are welcome.

Thanks,
Reinhard



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
Bench Top Horizontal Mill Stands/Cabinets Too_Many_Tools Metalworking 2 August 24th 04 12:51 AM
Horizontal sync problem? RubyTwoShewz Electronics Repair 3 June 3rd 04 10:33 PM
RCA TV - Model: F32665 / Chasis:CTC203CX Guy Petty Electronics Repair 10 May 4th 04 03:22 AM
TEK 7704A with dual sweep funky?? mike Electronics Repair 0 March 16th 04 11:10 AM


All times are GMT +1. The time now is 10:13 AM.

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"