Cheap china monitor issue

[pentium]

Earlier this summer I bought two 900Mhz wireless cameras for $25 used.
The kit also came with two monitors that had a dual channel receiver installed in each of them (Channel A and Channel B)
Anyways, while one monitor works, the other does not. I push the power button and nothing happens (I don't even hear the flyback energize), I checked the PSU, the cord, the power connector and even the fuse and they are all okay. I can't seem to figure out why it will not turn on. The power button is a pushbutton on/off switch so it is either on or off.

Well, what could it be?

[Wizard]

Re: Cheap china monitor issue

Pentium, you gonna have the MUST HAVES checks. With meter on the voltages and other things like resistance checks on other components and eye and nose to smell for any stink that comes with overheating/shorting.

Be careful.

Cheers, Wizard

[Krankshaft]

Re: Cheap china monitor issue

Check the flyback carefully for any melted plastic. I would ring it to make sure it's ok.

Check the HOT for shorts although they usually like to take fuses out with them.

Check the line voltage regulator too.

If you want to measure for voltage push in the power switch and plug it in and measure across the line filter cap. This is the output from the line voltage regulator and it should be the same voltage that the regulator is rated to output.

[Krankshaft]

Re: Cheap china monitor issue

Doh . Sorry about that the line filter cap is BEFORE the line regulator so disregard that statement.

The voltage on the cap is the INPUT to the line regulator.

Very tired now and the old noggins slipping up on me .

If voltage is at the cap check the collector of the HOT for regulated voltage.

As always when working with line voltage be careful.

Just trace your way through the high voltage power supply and I'm sure you'll find your culprit.

[pentium]

Re: Cheap china monitor issue

I checked the regulator and it seems fine.
I checked the flyback and even the caps are not holding a residual charge so either there is a short or they have not seen power in a while.

[Wizard]

Re: Cheap china monitor issue

that means you don't have the power to the horizontal section.

Short or dud regulator can do this. What kind of this voltage supply to the horizontal section is designed?

I'm not talking about power supply if it's not on board the chassis.

Cheers, Wizard

[pentium]

Re: Cheap china monitor issue

that means you don't have the power to the horizontal section.

Short or dud regulator can do this. What kind of this voltage supply to the horizontal section is designed?

I'm not talking about power supply if it's not on board the chassis.

Cheers, Wizard

Heck do I know.
Like some people I tend to not even open my CRT monitors.