Toshiba PD1843 Degauss not working

[chriszhxi]

I have a toshiba pd1843 which is awesome except degaussing is not working, and I think because of this, edge corner color is bit off .

When push the deguass button on the remote board, it will give a 300 sec countdown, after that nothing happens, push the button again, shows "degaussing" on screen but it actually not working.

Anyone got idea how to fix it?

 

[nem]

Let's start with the simple stuff first.

Is your degaussing coil plugged in? It should be connected to P803.

 

[chriszhxi]

Let's start with the simple stuff first.

Is your degaussing coil plugged in? It should be connected to P803.

Yes it is, I tried with other chassis, degaussing works fine.

 

[nem]

Does the relay click when you press degauss?

 

[chriszhxi]

Does the relay click when you press degauss?

No, I didn't hear clicking sound, completely silence.

I got a spare 1843 which does not work in 15khz but also don't know whether degaussing works, but I will try replacing the two black blocky thing I believe it's the relay first.

 

[nem]

Try that and see what happens.

 

[chriszhxi]

Try that and see what happens.

I replaced the replay, still the same, then I did a close inspection around that area and noticed something unusual.

There is a magnet cuboid stuck right between legs of the big white thing (picture is from internet, underneath the white thing, it stuck there so well I didn't notice it as an "outsider" before), I can tell it's the magnet around the edge of tube yoke. A while ago I did a yoke change, it probably fail to there when I was swapping the yoke.

I took out the magnet and tried again, still the same.

Is it possible some of the components are damaged by the magnet? From outside visual inspection, I couldn't tell.

Any suggestion for what to look for or what to replace?

 

[nem]

I doubt it has anything to do with the degauss not firing.

If there's no click coming from the relay, it means it's not being thrown. Looks like the relay is connected to some SMD components on the solder side.

See if you can spot a blown component?

 

[chriszhxi]

I doubt it has anything to do with the degauss not firing.

If there's no click coming from the relay, it means it's not being thrown. Looks like the relay is connected to some SMD components on the solder side.

See if you can spot a blown component?

Yes! I found two missing SMD components D817 D818

I checked the spare 1843, it;s also missing D818

I also checked my other 2367 chassis.

D818 seems is a SMD has label 18 or 1B on it, same with D809.

Do you think it's ok to replace the missing D818 with D809? I also notice there is a vertical line on it, which side the line should be when I put it on D818? On 2367 it's on the right side, but on 1843 I'm not sure if it's the same.

 

[chriszhxi]

I doubt it has anything to do with the degauss not firing.

If there's no click coming from the relay, it means it's not being thrown. Looks like the relay is connected to some SMD components on the solder side.

See if you can spot a blown component?

I just put D817 and D818 back on, and degaussing is working now! It sure is because of the these missing SMD components, you are right on the point, awesome! thanks for the help!

Now I finally have a full working 1843 chassis, next thing to do is a full recap for it.

 

[nem]

Oh, nice! Good job!