View Full Version : Flaky G2 control on a Hitachi . . .


zenith2134
05-27-2007, 07:44 PM
Hey all.

Well, call me crazy but I picked up an 82 Hitachi color set the other night. :scratch2: :scratch2:

Its a 19" tabletop model with pressboard cabinet and semi-electronic tuning. Ive yet to find any REAL TV's around here so I guess I got a little desperate.:D

Basically I reseated and cleaned the 2nd Anode to get the set running correctly. It had visible corona discharge due to massive amounts of dust (and age, I suppose). Well I set up the grayscale and it made a great picture, until the white level began fluctuating, So I found the screen voltage was erratic, dipping from about 350v to about 400v which I presume is normal for this set.

Turns out the g2 potentiometer is causing this, and I was wondering if anyone has any ideas on how I can save this set W/O replacing the fly...If thats plausible ..I also realize I may have internal arcing.

I really like this TV- the cabinet is styled like an early 70s set, not early 80s and the (simulated)woodgrain is very detailed also. [lol]

I have reason to believe this uses an RCA Tube , IIRC I read in one of the TV forums here at AK that they rebadged some RCA crts to read Hitachi.

Anyway, thanks in advance for any help here, and sorry if I have wasted your time

andy
05-28-2007, 02:06 AM
You could try flushing the control out with a cleaner like deoxit, or alcohol. You may be able to get more cleaner in the control my melting a small hole in the plastic near the pot. There is usually some air space around the G2 and focus pots which are usually on a ceramic substrate. If you have to make a hole, be sure to seal it with silicone when you're done.

zenith2134
05-28-2007, 03:43 PM
So I guess using some silicon filler is generally safe in this area? Seems like a good idea.

Just didn't want to make a mess out of the xformer with contact cleaner...I'll give this a go next chance i get.

andy
05-28-2007, 07:30 PM
It's one of those cases where you have nothing to lose. You might look into buying a replacement flyback. If you can find one, it might not be too expensive. The last flyback I bought was only around $20 and that was for a 32" HDTV.

zenith2134
05-28-2007, 07:43 PM
Agreed, Ive got nothing to lose here.

I found a site called maine electronics.com that lists the flyback, part number 2432811 for $41.40 - I think i'm gonna give the shot of contact cleaner a try first, lol. After all this is a trash find. Thanks for the tip, Andy:thmbsp:

Nakdoc
05-30-2007, 05:22 PM
Check Electronica...ask for Bill 800-722-5578 you will have several choices. Bill is a flyback expert.

fsjonsey
05-31-2007, 12:25 AM
My Parents recieved the exact same model set in 1982 as a wedding present from my grandparents. It was our main set untill 1996, when we inherited a then new 25" zenith from an uncle who had passed away. When the CRT in the zenith blew the next year, on thanksgiving day, the hitachi again became our main set untill 1999, when my dad bought a 25" sanyo. The sanyo was destroyed in a lightning strike in 2003, and replaced by a Phillips 27", whose flyback failed last summer. The Hitachi again became our temporary set untill we purchased a 37" Westinghouse LCD HDTV. It was still working fine when my father dropped it off at the Salvation Army Last fall. It turned up there again this spring, same set, because it had the replacement coax connector I installed in 9th grade. Nice to know people are still using it. I grew up with that set.

zenith2134
05-31-2007, 12:57 AM
I drilled a hole in the transformer, and squirted a tiny bit of deoxit gold in there...The pot instantly felt smoother...the usual good indicator. I patched it up with silicone gel I had lying around... It seems too good to be true, and I ran it for about 3 hours with no arcing, no screen fluctuations, and no trouble! Awesome, now ive got another 80s set that'll run for the next 100 years, lol.

Oh, and the EIA on the tube is 188, which I know know is GE from bgadow's help in my GE portable thread.

AK has helped once again..

Cool that someone else has pushed this set hard and enjoyed it for years too, I love hearing old TV set stories