My beloved display went bad

[Behemot]

Re: My beloved display went bad

Oh man the Samsung SyncMaster 1200NF I have right now smeels like some PCB is heavily burning inside. I lowered the resolution from 1792x1344 to 1600x1200 and it's slightly better yet nothing wonderful.

first check for broken soldering - very common.
then replace all small electrolytics around the deflection chip(s)

that will probably fix the philips

I don't really have experience with CRTs from inside. OK, the deflection chip is the one usually in strange 13pin package with tab, mounted on heatsink? Or should I just measure all small caps with ESR meter?

[stj]

Re: My beloved display went bad

that's the chip, you could use the meter but given the age and the fact that it gets hot - your probably going to have to replace all of them either way.

[momaka]

Re: My beloved display went bad

first check for broken soldering - very common.

Agreed.

"Late" model Sony CRTs tend to have a lot of bad joints. D board and G board are prime suspects as they have some of the heaviest components and are usually mounted vertically.

As for discharging the tube - you can use 100 to 500 kOhm bleed resistor. No, it will never explode! While the initial voltage stored in the tube could be up to 30 kV (although it rarely is and usually discharges quickly after power-OFF), the voltage in the tube will fall very fast with the bleed resistor as the tube (a giant HV, low capacitance capacitor essentially) doesn't really store that much energy after all (much less than 1 Joule typical).

Lastly, the monitor with the darkened spark gaps may have a failed flyback or failed tube (as in, gone to air). If the tube is bad, you will see a blue glow from the neck of the CRT tube where the electron guns are.

BTW, if you have time, post some pics of the insides of these monitors. Would be cool to see.