differences (on the inside) CRT and Bigscreen

[cack01]

Out of all the forums I visit, this was the only one I knew of that could possibly answer this question.

I have repaired a few TV's (CRT type) in the last month, and my friend mentioned that his bigscreen (don't know make or model yet) has been having some picture problems.  I told him if could find out what was wrong I would work with him to "try" to repair it.  I am just wondering how much different on the inside these big screens are than a regular CRT.  Its an old set, so its nothing like the new ones which have digital mirrors and such.  Just an old school big screen.

Thanks for any info you guys can give me.

[Ken Layton]

The newsgroup sci.electronics.repair has lots of techs that repair tv's and bigscreens.

[cack01]

thanks I'll head over there.

[ericball]

Functionally a CRT based projector is similar to a CRT based TV except there are three small high-intensity monochrome CRTs (RGB) which are designed to emit light, through a lens, onto a screen.

Because there are three light sources, projection TVs can have convergence, alignment and color balance problems.  Any because they are high-intensity, they tend to dim over a shorter period of time as the phosphor dies.