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oops! coffee into the top of TV!

Did a bad thing to our little portableTV, a Funai, Model FT1371

EVENTS: Set coffee cup on top of TV, jostled the TV's table, liquid went down through the holes on top, and voila! Screen shrunk, went black - However, I quickly unplugged just as TV was going black.

DIAGNOSIS: Took apart case to find liquid had run onto the HV connection, ran down HV cable to where cable was lying against the PCB on back end of tube. At that location, suspect arc over to electronics [Electronics was a bare solder tab sticking out with bare copper wire going to a winding] and what appears as a 1/16 inch discoloration on side of HV cable. Possibly always touching there and that was dirt aging, or from an arc caused by the liquid.

ACTIONS: Cleaned everything up, dried off, reassembled. TV came on! Lit up! Talk about lucky. But...colors went all wonky. At first everything was all red [must not have been completely dry]. Let run a couple of hours to dry completely, Colors shifted, but now predominantly green.

OBSERVATIONS: White appears to contain excessive green. Good news is that pure red is pure red. pure blue is pure blue. Black and White programs are green and black, not black and white.

For what it's worth, I think I've seen this type of color once on a similar inexpensive TV caused by some cheap pots near the CRT. Those little plastic disk thingies with a metal wiper. All the structure's are open to the atmosphere and not sealed at all. Simply, ajusting the color [wiggling the wipers] returned color to original settings, brought the color back that time.

QUESTIONS:

1) Any schematic for a Funai FT1371 ? 2) Anybody know what got zapped on the top tab of that PCB? 3) Assuming each video color channel is still capable, what adjustment to bring back color balance?
Reply to
Robert Macy
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Hi!

Just out of curiosity, how'd you dry the TV?

Water can hide in controls and components. If you didn't, I'd put the opened TV in the sunlight for a while. The natural heat will drive moisture out of the places where you can't see or directly dry it off.

William

Reply to
William R. Walsh

I would not advise you to make any colour balance adjustments. These are not usually used unless to compensate for component drift with age, or after replacement or other scenarios where recalibration is needed; the problem here probably lies elsewhere. Only tweak if you are sure liquid got at the pots, and even then, mark the original position with correction fluid or a marker pen. The fact that you have already seen the colour shift from red to green might well mean that all is not yet dry.

Firstly try removing and reinserting the small pcb on the neck of the tube, check to see if any liquid made it to the pins or the CRT socket. Usually this pcb contains the RGB output IC or transistors...how old is this TV?

-B

Reply to
b

Thank you for your reply.

Should be dry. It's been 48 hours with perhaps over 30 hours of operation. This TV being old runs a bit toasty. At the timeof the accident, I expected the residual heat, coupled with the constant operation since then, to be able to thoroughly dry everything out. Also, being in California, drying is fast.

Will try that remove insert. and generally mechanically manipulate everything. I don't think the PCB itself was washed, rather the HV electrode wire was washed, flooding down to the bare terminal on the PCB where very likely grounded out the HV. That's why the image shrunk ultimately going black as the HV died. There is high probability that the short to gnd path 'injured' low voltage components.

White is not white, but greenish, like underwater now. I can't tell if a color is missing, or green is simply too strong. It appears that red is there, blue is there, green is there, flesh tones are almost ok, but not quite. It may be that 1/2 blue is now 1/8 blue, or such. Like very distorted transfer function. like a leaky transistor that keeps signal very low until finally it can get turned off. And leaky transistor would make sense with a zap going into the PCB somewhere. It would help to have a schematic yo find out just where that discharge entry point was.

Age? label said manufactured January 1998 Funai Model FT1371

Robert

Reply to
Robert Macy

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