G07 Still Dead
- When Everything Else Fails -
Here's a tip of last resort when you've rebuilt your G07 chassis & it's still dead when you reinstall it. This one came about years ago when ops were sending in G07 chassis' for repair & in the beginning I noticed a few instances of them being reported dead on arrival periodically. Each case ended up being the same... cracked PCB & after the third one was returned I discovered that it wasn't a shipping accident as previously thought. After finding the cause a caution sheet accompanied every G07 chassis that left the shop. Over the past 10 years it has helped many a hobbyist that has run into this stumbling block and asked for help, but I failed to post it on site, so I will put a copy of it here now before I forget & maybe it will be beneficial to others.
Dang! It's all in caps! Maybe that's why I've been dragging my feet :-( It's only a few lines, so I'll just type in here as it appears:
G07 Installation Caution
This chassis has been inspected for PCB breaks & found to be sound in every respect. For years there has been a problem with operators reinstalling these chassis' & cracking the PCB from one of the front screws that hold the transistor heat sinks. These heat sinks hold the back 6 inches of the PCB rigid, while the front 2 inches is kind of suspended in air. This and the stiff upright tabs sticking up midway that hold the PCB to the frame, do not allow the back of the PCB to give in any manner. Now if you look at the front of the metal frame you will see 2 spring tabs sticking up to hold the front of the PCB in place. When installing the chassis you must guide & watch these front tabs that hold the PCB in place. What often happens is that the PCB slips up over the top of these spring tabs & since the back cannot move at all, the PCB cracks right at the end of the rigit frame.
The advantage here is that I can add a couple pics that should help.
I'm sure many of you have seen jumper wires on the bottom side in this area & now you know why. Another crack site is anywhere in the circumference of the flyback pins & this comes from not completely removing the solder when changing one & prying on the old one to get it out. Spend the time to resolder a pin several times, if necessary, in order to get a pin completely free from the PCB. This is true when removing anything soldered in.... when the solder gets old & doesn't want to evacuate the mounting hole adding new fresh solder will meld in with the old making it easier to remove.
Hopefully this will save someone from scrapping a good G07 chassis...
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