Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Vintage TV & Radio Tech Forum (http://www.videokarma.org/forumdisplay.php?f=170)
-   -   Chromacolor II issues (http://www.videokarma.org/showthread.php?t=270243)

Laserdisc 03-16-2018 09:28 AM

Chromacolor II issues
 
1 Attachment(s)
I have worked on this thing off and on for about half a year now trying to get it to work right to no avail. It looks like this to the naked eye but to see what it looks like on camera here's a YouTube video. I have audio and it'll happily run like this without getting hot or anything so I don't know what it's deal is. I've replaced almost every single electrolytic capacitor in the set, checked connections, tried every adjustment, nothing. Might as well have not touched it for all the good it's done so far,help. https://youtu.be/iXdkJ7yv6rs the popping isn't the set, that's explained at the end of the video.

zeno 03-18-2018 07:50 AM

Quote:

Originally Posted by Laserdisc (Post 3197241)
I have worked on this thing off and on for about half a year now trying to get it to work right to no avail. It looks like this to the naked eye but to see what it looks like on camera here's a YouTube video. I have audio and it'll happily run like this without getting hot or anything so I don't know what it's deal is. I've replaced almost every single electrolytic capacitor in the set, checked connections, tried every adjustment, nothing. Might as well have not touched it for all the good it's done so far,help. https://youtu.be/iXdkJ7yv6rs the popping isn't the set, that's explained at the end of the video.

Wow never seen that before & I worked on thousands of these.
Can you turn the brite down ? Is the vert fuse OK? IIRC 6/10 amp.
Whats the chassis # ?

73 Zeno:smoke:
LFOD !

Laserdisc 03-18-2018 04:20 PM

That makes me feel less incompetent at least. Only two fuses I can find in the set are good. Controls effect nothing. Chassis 13JC10

zeno 03-18-2018 07:11 PM

13GC10, 13HC10, 13J10, 13KC10 all almost the same set.
Basically a console chassis stuffed in a 13" set ! AND they
kept it serviceable...... I got the 1st one that came in (13GC10)
a real sweet set. Unpacked it & loved it so much it was soon
on the seat of my Toronado for the ride home.

1) Check the 9-88-? video module for cold joints under the
white resistor pack.
2) On CRT module check voltage on collector (C) of one of the video outputs.
3) Each video out on CRT socket the C goes to identical resistors. Typically
about 15K ohm 2 watt. Where they all join at one end measure that also.
4) See what happens if you turn down the G-2 ( A.K.A. screen) on the
CRT board, return it to back after.

That should narrow things down.

73 Zeno:smoke:
LFOD !

Laserdisc 03-19-2018 02:38 PM

Currently checking out the rest. G2 doesn't have any effect whatsoever. No cold solder. On the collector of Q1205 I read 38.7vdc with the set running on 110vac on the variac.

zeno 03-19-2018 05:51 PM

OK lets get this fixed. Manual is in hand.......
First this does NOT have the 3 identical resistors. They
are built into the resistor package. The 3 outputs should read
abt 175 VDC on the C ( K of CRT ).
Rule is with in-line CRT the lower the K volts the brighter the pix.

Check pin 2 of U1202 ( long resistor pack) should be abt 230 VDC.
Check wiper of G-2 should be abt 500 VDC. Be SURE your meter
is safe at that voltage ! If its high check R1214 ( 1.8 meg carbon )
off one end of the G-2 control.

good luck
Zeno:smoke:

Laserdisc 03-19-2018 06:04 PM

I'm not sure how I'm going to check the resistor pack with the board plugged into the crt,but I'll go check g2 and edit this with the result.

Edit: ok I wasn't 100% sure which pin of g2 was the wiper with how it's layed out but none measured more than 130vdc.

zeno 03-20-2018 05:41 PM

230 V can be measured on the red/white wire to connector P/J206.
G-2 can be measured at R1210 near green control.

try that

Laserdisc 03-20-2018 06:05 PM

I'll check that voltage,but what I meant on G-2 was I tested all three pins and all measured around 130v.

zeno 03-20-2018 07:42 PM

OK G-2 needs to be apx 500VDC.
Easy voltage divider.
800 VDC comes in on grey wire at J205 pin 6.
Through R1212 680K to one end of G-2 control.
Wiper goes to CRT via R1210.
Off other end of control R1214 1.8 Meg goes to ground.


All times are GMT -5. The time now is 09:46 PM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.