neotec 2702 parts id

[grantspain]

hello chaps,i have a bit of bother.
i have a neotec 2702 chassis which is missing some parts and i can't seem to find a schem online anywhere.
the components i need to know the values of are as follows,
C423 polypropylene high voltage cap on the hot collector
Q402 hot

cheers

[grantspain]

there is a neotec subsection on randy's tech site
q402 looks like a 2sc4542
c423 is 563 250v 56000pf  0.056uf i believe

[Ken Layton]

In the Neotec NT-2700/2701/2702 manual the horizontal output transistor is listed as type 2SC4542. However, in the model 2701's (EGA resolution) that I've worked on, they come with a type 2SC5150 (crosses to an NTE 2639).

Schematic says C423 (which has one end connected to pin 7 of flyback and Resistor R431) is .056 @ 250 volts. This cap is not connected to the horizontal output collector.

There are three caps connected to the horizontal output collector: C421, C420, and C419 and the values are not listed!

[grantspain]

i will double check my chassis,maybe i wrote the wrong cap down
the worrying aspect is why these components are missing in the first place,i found chassis hiding under a work station-its probably been there for years as the previous tech could not fix it

[grantspain]

now this is getting worrying,someone has put a 0.47uf 400v in place of c423 .
could this have damaged the flyback?

[Ken Layton]

Neotec flybacks fail alot so it's possible that the flyback simply went bad. As to the capacitor correct value, I think you'll have to eyeball another 2702 chassis and see what value cap it has there.

Of course you could send an email to Neotec tech support and ask one of the techs what is supposed to be there.

www.neotecgraphic.com

[grantspain]

i tried sending an email to neotec a few years back but they ignore anything that is from outside the U.S.

i will install a new 0.056uf 250v and a new 2sc4542 to see if i get any change then if nothing i will try the light bulb trick to prove the b+ is good.this way i should prove flyback at fault before having to import one from the usa

i spoke with the old tech today and he told me that before it stopped working the monitor would display a serious wobble on each side of the screen but it would clear after a couple of minutes