G07 vertical collapse issue

gunsablazin

New member
Joined
Aug 3, 2011
Messages
55
Reaction score
0
Location
houston, Texas
Ok, This chassis worked perfectly before I hooked it up to a donor tube and had the yoke wires hooked up wrong(backwards) i know , im an idiot !! but i'm learning
sizzle, sizzle, fry, pop!

Ok, actually just a little smoke came from either the flyback or a diode at D501.(which looked burnt-so assumed that was it.(looked on a working g07 and noticed D501 is not even used???? so i left it empty)

THE SCREEN SHOWS NOTHING BUT A BLUISH LINE HORIZONTALLY ACROSS THE SCREEN, WITH A FEW LINES JUST AN INCH OR TWO BELOW IT.(yes anode is at top of tube)
so here's what's been done.
1. installed new caps
2. new flyback
3. checked all traces visually and with a meter- all seem ok
4. switched out the ic501 chip
5. installed two brand new x401/x402 transitors
6. pulled out fr401 and it measured correctly (68ohms)
7. measured voltage at R1 and got 120v on leg toward the tube and 174.6 at the other.
8. installed new R908
IM GUESSING WHATEVER IS CAUSING THE COLLAPSE IS ASSOCIATED WITH THAT READING OF 174.6V BEING TOO HIGH? isnt it supposed to be closer to 145v?

***** The DONOR TUBE, YOKE, AND YOKE WIRES ARE ALL FINE AS I INSTALLED A WORKING G07 WITH NO ISSUES !!! *******

I am just about to change all 400's resistors..... PLEASE HELP me, Johnny
 
what have you done since?

Ok, This chassis worked perfectly before I hooked it up to a donor tube and had the yoke wires hooked up wrong(backwards) i know , im an idiot !! but i'm learning
sizzle, sizzle, fry, pop!

Ok, actually just a little smoke came from either the flyback or a diode at D501.(which looked burnt-so assumed that was it.(looked on a working g07 and noticed D501 is not even used???? so i left it empty)

THE SCREEN SHOWS NOTHING BUT A BLUISH LINE HORIZONTALLY ACROSS THE SCREEN, WITH A FEW LINES JUST AN INCH OR TWO BELOW IT.(yes anode is at top of tube)
so here's what's been done.
1. installed new caps
2. new flyback
3. checked all traces visually and with a meter- all seem ok
4. switched out the ic501 chip
5. installed two brand new x401/x402 transitors
6. pulled out fr401 and it measured correctly (68ohms)
7. measured voltage at R1 and got 120v on leg toward the tube and 174.6 at the other.
8. installed new R908
IM GUESSING WHATEVER IS CAUSING THE COLLAPSE IS ASSOCIATED WITH THAT READING OF 174.6V BEING TOO HIGH? isnt it supposed to be closer to 145v?

***** The DONOR TUBE, YOKE, AND YOKE WIRES ARE ALL FINE AS I INSTALLED A WORKING G07 WITH NO ISSUES !!! *******

I am just about to change all 400's resistors..... PLEASE HELP me, Johnny

I see your laundry list of items you change I assume you didn't do all that after you hook up the yoke wrong? Let us know what you have done since this mistake? We have all done it.
 
Everything in the list has been done to try and get this chassis back up and running AFTER I sizzled something by hooking it up wrong. Thanks
 
wow okay

Might help, have you tried removing x701 and turning it on? If you are having high voltage it might fire it up. Also double check your caps polarity and remember one is misprinted on one side of the board. Especially check c511. I assume by what you have tried you have a flow chart?
 
how did you hook the yoke up backwards? the conector only allows it to be put on one way. was it broke into four pieces? check the yoke and see if its blown ohm it out to see if it is still good. check f401, rotted, had them test good then wiggle them and would be open.
 
Last edited:
Donor tubes yoke connector had red(v) key, (v) blue, (h)yellow, (h)brown.
Didn't read bob Robert's page on yoke flipping in time. As you know and I have learned the G07 goes v, key, h, v, h

I pulled fr401 and reinstalled checked ok.

The yoke / tube / wires are fine used with a working g07.
 
Thanks guys for trying... I'll put this one on the shelf for a while- rebuilt two more chassis' and then installed with this tube- they look great! (scratching head)...
 
Back
Top Bottom