toshiba tv dead after brownout

[ruinkaster]

we run a generator where we live, the gen went down and we had a brownout. before we could get the tv turned off the power went completely out. when it came back on, we turned the tv back on but got no picture. also, it chirps and makes strange noises when plugged in. it is a toshiba 32". we have tried unplugging it for 24 hours but no change. there are fuses but all are intact. is there a reset? is it dead forever? can someone help?
thanks for your time, i can supply more info if needed but i dont have the tech language so please be patient.

[willawake]

Re: toshiba tv dead after brownout

i dont have the solution, there is a few on the forum that can help. We have crappy mains power here in Greece and run the TVs and audio equipment off APC LineR 1200VA units for surge protection. might want to check those out for your use.

looks like something screwed in the power section though. might be repairable by the right tech.

[kc8adu]

Re: toshiba tv dead after brownout

repetitive chirping/clicking is usually a short on a smps output.
like a shorted h.o.t.

[ruinkaster]

Re: toshiba tv dead after brownout

repetitive chirping/clicking is usually a short on a smps output.
like a shorted h.o.t.

yep...the patience factor should click in right about now...
what is a smps, or a h.o.t.?
we live in a remote part of alaska, have a lot of time on our hands, and know just about enough to know you never touch anything inside until its been unplugged for awhile...

[willawake]

Re: toshiba tv dead after brownout

kc8 speaks on another level but his info is #1

you will need a tv repair tech

switching mode power supply
horizontal output transistor

[Spacedye69]

Re: toshiba tv dead after brownout

www.repairfaq.org

They also tell you how NOT to die!

[arneson]

Re: toshiba tv dead after brownout

I've seen Zener diodes go out that way also,
but again you're into the repair tech domain.

[chipper]

Re: toshiba tv dead after brownout

If your generator caused the problem in the first place , it had the problem , not the tv. Nevertheless , if the generator went out as a result of a storm or power shortage , the source of power is where the chirping is coming from because of a lack of power to run the component.

I used to have a 27" tv hooked up to an RV type setup with a 1500watt inverter. When the source (battery) ran low , the inverter would only power the unit enough to cause what is heard as "chirping". This is the current flowing but not able to power the component (tv) because of a lack of power in itself , not the tv. (engine on RV stopped from lack of fuel while I was asleep) [valve not open for extra fuel tank]

Engine stopped for 4 hrs.

Since I set up everything myself with house (120v) wiring to the batteries (4 new x 12volt -1000 cold cranking amps each) , and I bought the inverter new , I knew immediately that the source of power was low. I opened the 4 battery box and found 1 battery to be completely low (inverter connected to it) - (bridgings to other 3) - were at half power. The entire system was not able to run the inverter below 10volts and had a safety shut down feature built in by manufacturer. Stopped inverter after 4 hours of running full battery source only.

No damage came to anything , boosted main battery (inverter connected) , "opened fuel cock to extra tank" , and ran engine for 2hrs before restarting tv. Everything was fine.

So , if your generator took a hit from a lightning source / bad current source or fault of it's own , it is probably where you have some sort of damage that needs to be fixed.
You need to check the generator for any signs of bad caps or some sort of lacking system normality , and repair it first. Then run the tv.

[Krankshaft]

Re: toshiba tv dead after brownout

It definately sounds like a power component fried.

Most likely semiconductor related HOT, Line (or B+) Voltage Regulator, or something in the SMPS. Sometimes chirping can be a protection circuit on the SMPS kicking in.

I remember when I was working on an old 19" tv and was measuring the output from the 130 volt rectifier (back when B+ could still be adjusted with a POT) and my probes touched. POP!

I created a dead short through the regulator as a result the TV still powered up but the horizontal sync was off.

And since the horizontal lock was um nonexistant the stable high pictched whine that we are all accustomed to hearing on CRTs was very variable as was the picture .