Had a working G07 19" monitor and decided the Shinobi burned-in tube had to go. Found a TV (made in 1980) with a chassis and neckboard that looked an awful lot like a WG49xx series chassis (the neck board is dead on). Knowing WG49xx and G07 tubes are the same prompted me to swap it into the G07.
Upon power-up F901 blew instantly (F902 and the HOT both test fine afterwards) and I heard just a faint crackle (HV) before it did. The degausing coil was plugged in. My thoughts are:
- The tube is not the same as I expected and not compatible. The G07 tube is a Rauland 19VMJP22 and the TV tube is an RCA, but I can't find any identification numbers any where on it. The G07 Rauland tube is an 8-pin and the TV RCA tube a 10-pin (which means the chassis should simply ignore them, I have been told).
- I did not swap yokes, since I have had good luck on the last couple of tube swaps (G07 & WG49xx series). The yoke wires had a slightly different pin connector, so I had to break the plastic holder. Said another way, a G07 has 4 yoke wires and there are 5 pins on the chassis it connects to. There is a spacer between the larger red wires and the first of the 3 smaller wires. The TV did not have that spacer, so I broke the larger red wire away from the others. I am sure the red wire was plugged in correctly on the G07 chassis, but have no way to verify if the other 3 were swapped around. However, even if they were, it would only mirror or flip the image (perhaps not, see below).
- The G07 chassis was capped within the last year or two, but the flyback looks to have some age. Could it have gone during over the last 3 weeks, since the last time it was used? Sure, but I have not doubts, but admittedly I didn't test it before doing the tube swap (my bad).
- The TV worked a year ago when I turned it on and chances of just the tube going bad during that time is very remote.
Alright, after typing all of this up it occurred to me I never tested the vertical impendence of the existing TV yoke. Well, it turns out the original G07 yoke is 55 ohms (vertical) and the TV yoke is 30. Weird number, but way too far off for it to have made a good picture. Further, I noticed the TV yoke has one of the vertical and one of the horizontal wires swapped in the yoke connector that attaches to the chassis. That is probably why F901 blew.
I'll swap the yokes and replace F901, plus test some other items and see if that solves the issues. Ah, well... an exercise in bad practices...
Scott C.
Upon power-up F901 blew instantly (F902 and the HOT both test fine afterwards) and I heard just a faint crackle (HV) before it did. The degausing coil was plugged in. My thoughts are:
- The tube is not the same as I expected and not compatible. The G07 tube is a Rauland 19VMJP22 and the TV tube is an RCA, but I can't find any identification numbers any where on it. The G07 Rauland tube is an 8-pin and the TV RCA tube a 10-pin (which means the chassis should simply ignore them, I have been told).
- I did not swap yokes, since I have had good luck on the last couple of tube swaps (G07 & WG49xx series). The yoke wires had a slightly different pin connector, so I had to break the plastic holder. Said another way, a G07 has 4 yoke wires and there are 5 pins on the chassis it connects to. There is a spacer between the larger red wires and the first of the 3 smaller wires. The TV did not have that spacer, so I broke the larger red wire away from the others. I am sure the red wire was plugged in correctly on the G07 chassis, but have no way to verify if the other 3 were swapped around. However, even if they were, it would only mirror or flip the image (perhaps not, see below).
- The G07 chassis was capped within the last year or two, but the flyback looks to have some age. Could it have gone during over the last 3 weeks, since the last time it was used? Sure, but I have not doubts, but admittedly I didn't test it before doing the tube swap (my bad).
- The TV worked a year ago when I turned it on and chances of just the tube going bad during that time is very remote.
Alright, after typing all of this up it occurred to me I never tested the vertical impendence of the existing TV yoke. Well, it turns out the original G07 yoke is 55 ohms (vertical) and the TV yoke is 30. Weird number, but way too far off for it to have made a good picture. Further, I noticed the TV yoke has one of the vertical and one of the horizontal wires swapped in the yoke connector that attaches to the chassis. That is probably why F901 blew.
I'll swap the yokes and replace F901, plus test some other items and see if that solves the issues. Ah, well... an exercise in bad practices...
Scott C.
