Mitsubishi VS-4543 PTV, blows fuse as soon as powered on

B

Benjamin Bair

Guest
Got a Mitsu VS-4543, blows main fuse as soon as unit is turned on.
Checked for bad solder joints, bad caps, shorted HOT, rectifier,
regulators, and diodes. Absolutely no evidence of overheated or
thermally damaged components.

Question #1, does anybody happen to have schematics and/or service
manual for this set, or know where I can get a copy relatively
cheaply.

Question #2, would a shorted yoke cause this, without blasting the
HOT? Would a fried STK do this as well (don't know how to check the
STKs)

Question #3, does anybody out there have experience with this set, and
maybe be able to point me in the right direction? I can't seem to find
the failed components.

I'm pretty new to repairing TVs, although I have a solid electronics
background and have been able to keep my 10 year old Zenith PTV going.
It is a very enjoyable new hobby and newsgroups like this are a great
resource for learning.

Thanks in Advance!

Ben
 
#1 the print prob is still avail via MGA,
#2 With this set you better have a very good esr meter and know how to use
it
#3 Yes a yoke or shorted crt can and will take out a protect device
#4 Expect to spend at least 1 - 20 hours even witha grod schema
#5 maybe you should call a MGA service and at least have them give you an
expert opinion or have them look at the set and give an estimate of repair.
Enjoy und Happy Holidays
"Benjamin Bair" <bbair@compdoconline.net> wrote in message
news:78eee655.0312152114.34f2f114@posting.google.com...
Got a Mitsu VS-4543, blows main fuse as soon as unit is turned on.
Checked for bad solder joints, bad caps, shorted HOT, rectifier,
regulators, and diodes. Absolutely no evidence of overheated or
thermally damaged components.

Question #1, does anybody happen to have schematics and/or service
manual for this set, or know where I can get a copy relatively
cheaply.

Question #2, would a shorted yoke cause this, without blasting the
HOT? Would a fried STK do this as well (don't know how to check the
STKs)

Question #3, does anybody out there have experience with this set, and
maybe be able to point me in the right direction? I can't seem to find
the failed components.

I'm pretty new to repairing TVs, although I have a solid electronics
background and have been able to keep my 10 year old Zenith PTV going.
It is a very enjoyable new hobby and newsgroups like this are a great
resource for learning.

Thanks in Advance!

Ben
Click to expand...
 
This is a VZ3 chassis....easy to work on.

Remove the Horizontal Output and see if it still blows the fuse. If
so.....all the H-sweep related stuff can be eliminated.

Check for a dead short across the main B+ filter cap for the power converter
IC900 ( STRM6811)......if you read a short there , remove IC900 to see if it
goes away.


You should be able to run the set without the H-output and verify good
regulated voltage at the collector pad.

IC900 is a common failure for your symptom.




--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
jstielau@snet.net
========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd


"Benjamin Bair" <bbair@compdoconline.net> wrote in message
news:78eee655.0312152114.34f2f114@posting.google.com...
Got a Mitsu VS-4543, blows main fuse as soon as unit is turned on.
Checked for bad solder joints, bad caps, shorted HOT, rectifier,
regulators, and diodes. Absolutely no evidence of overheated or
thermally damaged components.

Question #1, does anybody happen to have schematics and/or service
manual for this set, or know where I can get a copy relatively
cheaply.

Question #2, would a shorted yoke cause this, without blasting the
HOT? Would a fried STK do this as well (don't know how to check the
STKs)

Question #3, does anybody out there have experience with this set, and
maybe be able to point me in the right direction? I can't seem to find
the failed components.

I'm pretty new to repairing TVs, although I have a solid electronics
background and have been able to keep my 10 year old Zenith PTV going.
It is a very enjoyable new hobby and newsgroups like this are a great
resource for learning.

Thanks in Advance!

Ben
Click to expand...
 
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