[TechAssist] JVC TV AV2749S, yoke arcing at CRT neck
- From: Gary McCartney <gary@xxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Thu, 14 Aug 2003 01:16:49 -0400
I have this JVC TV model AV2749S in the shop and I have found that the
yoke is shorted where it wraps around the neck of the CRT, causing a
black burn mark on the glass. I took a knife and scraped it off but
there is a slight crater in the glass now, maybe 1/64 of an inch or so
deep. Is this a weak spot from now on, meaning that this spot will be
suseptable to more arcing in the future or worse yet, a crack in the
neck? Can I apply some epoxy to the spot to give it insulation, or
should this tube be scrapped? I have a used yoke which looks to be in
great shape which I can use in the set so I hate to tell the customer it
is garbage.
Here is a photo of the mentioned spot on the glass:
http://www.number63.ca/tube-neck.jpg
How I found the bad yoke:
The set came in with F902, 1.25 Amp fuse open. I couldn't find any
defective parts so I installed a new fuse in case that was the only
problem. Pressed power button and saw LED blink and that was all- the
fuse was open again. Next, I looked up tips and found one that mentioned
the yoke as a possibility, so I pulled the CRT board and the yoke
connectors. The LED came on and stayed. Then I reconnected the hor.
winding and put a new fuse in. Had to use 1.5A instead of 1.25. I used a
variac set at 90VAC and plugged it in. The LED came on and I heard the
arcing and saw smoke coming from the yoke/ CRT neck.
Thanks for any help.
--
Gary McCartney
McCartney Electronics
Guelph Ontario Canada
Est. 1984
email: gary (at) number63.ca
*****************************************************************************
Classifieds! Buy or Sell!
http://sell.tech-assist.org
The Tech Address Book:
http://www.tech-assist.org/secure/tip/contact.htm
Add a Repair Tip Here, or Change/Remove your Email Address:
http://www.tech-assist.org/secure/tip/main.htm
Lost Password:
http://www.tech-assist.org and select "Lost your Login Info?".
Email Archives:
//www.freelists.org/archives/techassist/
Other related posts:
