It's a longshot, but I thought I would try. Four year old Sony Trinitron TV - 27" - has power-on problem. If we shut it off, it is exceedingly difficult to turn it back on. When we try to turn it back on, it tries to come on and the little red lights continue to flash rhythmically. Initially, after a couple of dozen tries, it would finally come on. The manual refers to such a problem in troubleshooting, says to call repair tech if shutting off power does not clear the problem. We have repair scheduled, but just curious about what it could be and how difficult to repair. Hubby could probably stand the loss if he can upgrade to a giant flat panel.......... :o)
The owner's manual refers, I believe, to some sort of battery. Any DIYers who have repaired TV's with similar problem or know of online repair manuals?
I have most of the repair manuals for SONY TVs up to about 2003, however as another poster mentioned, even if you could isolate the problematic component, you'd have a hard time getting your hands on a replacement part. It's not like the older TVs where you could just replace a tube, or capacitor, and away you go...
However the problem on most of these units was the flyback which would fail... I've heard of one place (
formatting link
) which I believe you could order a replacement unit from, but they don't come cheap, quite often around $100 ... I've never dealt with them, but I've heard of many people ordering from them in other groups..
If you post the model of the TV, I can check and see if your model is in my growing collection of PDF documents.. :) At least if I have the shop manual, you could maybe do some more testing to confirm if it is the flyback.
You can try unplugging the set from the wall for a few hours, but it's unlikely to help. Costs nothing to try, though. Even if you had the knowlege, equipment and experience needed to troubleshoot the problem, you have no source for proprietary Sony parts.
Anyhow, TomH, check your email... I sent you a link to your service manual. Good Luck....
On another note, lucky me.... This morning, turn on my TV (SONY KV32S22) to watch something before leaving for work, and all was fine for about 2 minutes, the picture goes black on the bottom 1/3rd of the screen. the top
2/3rds screen shows black on both sides coming down on a slight v-shape, and horizontal black lines across the picture that is visible. Within about 30 secs, the screen will turn black, but sound was still there... Power off, turn back on, and it is fine for about 30 secs, then same thing all over again...Thought maybe the Video input I was using died, so tried with the Tuner alone, and it did the same... Damn... I checked the service manual, but there are way too many test points, and without much previous experience, no way of easily narrowing it down... Not sure I'm ready or patient enough to take the try to repair yourself path just yet...I hate to replace the unit, since the image was very clear, and the unit is about 7 years old... But I don't want to spend $150 for someone to look at it, and tell me it will cost me another $200 to repair... :(
I have a 15 year old 27" SONY that also had weird intermittent display problems. A good slap on the cabinet would clear the problem for a while. Since the image was sharp and clear when it was OK that meant the components and circuitry were good. The slap fix meant that there was a loose part, likely a cold solder, somewhere. The diagnosis agreed with the observation as, when the furnace came on causing thermal expansion, the problem appeared or, if already there, disappeared.
I am knowledgeable in electronics and a little on TVs. Opened the TV up several times but was unsuccessful in locating the problem because I couldn't reproduce the problem. If I cannot reproduce the problem then the TV repair guy would unlikely be able to do the same. I didn't want the set sitting in the shop for months and I didn't like their charges either. And who wants to tote around that hernia box.
Anyway after half a dozen tries over two years I got lucky. When my elbow brushed against a wire harness the problem appeared. I could jiggle the harness and consistently reproduce the problem. A close inspection of the circuit board connector pins revealed lifted solder pads from the donut holes. Iwould have never been able the cold solder by just looking. Resoldered the pins and the TV worked fine.
The next time another intermittent problem appeared I went straight to the jiggle test for all the wire harnessess. Use long wood rod so that you don't accidently get zapped. Being zapped is unpleasant but I have never come across any report of anyone having died. I quickly located the problem and it was again connector pins with lifted solder pads. Resoldered the connector and the image is now even sharper and clearer than it had ever been.
I had earlier posted my problem to the sci.electronics.repair NG and had terribly technical suggestions which were non starters. This was because the layout ot the PCB and the rest of the TV modules were so compact that it was impossible to stick even a simple multimeter probe to measure anything. And everything had to be insitu because the harness wires were not long enough to relocate the PCB to a more accessible place. After I posted my solution someone replied that SONY PCBs are wellknown for developing cold solder joints. Aha.
Its next to impossible your trying to repair any circuitry components yourself. If you want to have a go at fixing the TV yourself do the jiggle test. Nothing technical and no parts required. Cold solder joints are very easy to fix if you can find them. Else live with it or junk it. As consumer electronics products stand these days it is not worth shop repairs either. For what a service shop charges you might as well use that money towards the price of a new TV set.
Well you summmarized exactly how I feel... Ran some tests yesterday and it is sounding alot like cold solder joints... I will investigate on the weekend...
Last night I opened it up, and cleaned out the piles of dust accumulated inside... Since I didn't want to remove the anode cap, to discharge the tube, I only did some limited inspection. The C board looked like it was pulled back a bit, but that could have been from the handling to put the beast on the table :) Anyhow I carefully pushed it back in, visually inspected the undersides of the "A" board and "G" boards, and didn't notice any soldering issues. Plugged it in, and turned it on, and immediately noticed some horizontal lines across... Just tapped the "A" board a bit, and it cleared... Then it ran for about 5 minutes with no problems... It started acting up again, and eventually went black again. Nudged the "A"board, nothing... The with the back of rubber covered screw driver, I carefully nudged some of the componenets... And as soon as I pressed down on the Comb Filter (CM305), the image came back.... ran for about 30 minutes.. no problems...
Decided to just close it up, since I was getting late, and I wasn't going to touch anything on it anyway... Closed it up, put it back in it's place, plugged it in, turned it on, left it for about 3 hours, and it was working perfectly... This morning turned it on.. 10 minutes.. same story all over again... Hmm... so I figure something is probably loose, and needs further inspection. As someone suggested, probably a bad solder joint somewhere, so probably not a big repair. When I pressed down on CM305 I guess whatever it was, made a good connection, and stayed that way... Then when running it for 3 hours, it was fine, untill time to cool down, when due to thermal expansion or something, the connection is bad again...
Fixing a solder joint is child's play, however you need to find which one it is before fixing it... Which is the long part...
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.