Hi,

I have a NEC V920 19" monitor which seems to have a faulty flyback.

It was occasionally (once every couple of weeks) arcing internally somewhere - a quick, short arcing sound could be heard, and the screen would noticably dim for a short time.

Late last week it became quite frequent (a few times a minute), and finally a long arcing sound, and then the screen went blank.

The monitor seems to make all the normal sounds when turned on (you can hear the relays clicking), and the power light under the switch turns on (the power supply seems to be working), but there is no EHT being produced by the flyback (tested by placing an earthed screwdriver near the EHT connection on the side of the tube, under the rubber boot. No discharge. In fact, the screndriver can touch the metal connection, and no discharge is observed).

I've measured the voltages on the PCB connections to the FBT (T302), and there are five connections at ~120VAC, five with 0V on them, and one connection with 24VAC present. Without a schematic, I can only assume that this indicates that the FBT is being supplied with the correct voltage, and it has become open circuit internally.

Is the flyback a common fault in these monitors?

Are there any other tests I should perform before replacing the flyback?

Is it economically viable to replace the flyback in this monitor? (Or cheaper to buy a new one?)

Where is the best place in Australia (Perth) to buy a replacement flyback?

The flyback has the following codes on an attached sticker:
H0003931
F94056A F-801
MERITRON
CT-8733 00806A

Thanks,
Alex.

how did you go with this monotor? i am seeing related issues with a v921

I ring flyback,SMPS's xfmers,video heads,yokes and other x-fmrs using the calibration output of my TEK465 and two 0.1Uf poly caps:

http://www.iwaynet.net/~nesda/flypoor.html
http://www.iwaynet.net/~nesda/Dec02/Dec021.html
http://www.iwaynet.net/~nesda/Dec02/Dec023.html

and it works great.

HR Diemen of Spain makes top quality flybacks,SMPS transformers and test equipment which have ISO9001 & maybe ISO9002 certification,they are now the OEM supplier for Sony who as we all know have poor flybacks,the proof is on their website,CD ROM and paperback catalogs.
They also have free online specs for each of their products including schematics.

They manufacture the world's best flyback transformers:

http://www.hrdiemen.com/indexeng.shtml

At the above link you can lookup the winding diagrams and schematics of it as well.Here is an article that I contributed to NESDA:

http://www.iwaynet.net/~nesda/Oct02/Oct028.html
http://www.iwaynet.net/~nesda/Oct02/Oct029.html
http://www.iwaynet.net/~nesda/Oct04/Oct041.html

HR Diemen SA
Edificio Dimabel 08512
Saint Hipolit de Voltrega Barcelona
Spain
Tel: 34 93 850 23 23
Fax: 34 93 850 24 62

http://www.hrdiemen.es
http://www.flyback.com
E-mail:hr@hrdiemen.es
E-mail:marketing@hrdiemen.es
Attention:
Martha Bach
Sales Department

In the USA HR Diemen flybacks are available through:

Electronica
2828 E.Colfax Ave
Denver,Co 80206
USA
Ph:1-800-722-5578
Phone:(303)322-3037
fax:(303)322-1135
http://www.electronica-usa.org/

or

http://www.mcmelectronics.com

or

PRB Belt Company

now bought by:

Russell Industries Inc
3000 Lawson Blvd
P.O Box 508
Oceanside,New York 11572
USA
http://www.prbline.com
http://russellind.com/downl.htm

Ph:1-800-558-9572 Press # 1(PRB/Russell)
Ph:1-800-645-2202 M-F=9:00-5:30 EST
Attention:
Larry

or

Tritronics
http://www.tritronicsinc.com/lookup_cs.htm

Sidney
Dartmouth,Nova Scotia
Canada

http://www.iwaynet.net/~nesda/May02/May18.html
http://www.iwaynet.net/~nesda/SonyAudMod.html

http://www.iwaynet.net/~nesda/Oct02/Oct028.html
http://www.iwaynet.net/~nesda/Oct02/Oct029.html
http://www.iwaynet.net/~nesda/Oct04/Oct041.html

http://search.yahoo.com/search?fr=slv1-msgr&p=ct-8733

That link shows a place where you can purchase the flyback online. $34.99 USD + freight to AUS.