David Aurora
Member
- Joined
- Jun 5, 2014
- Messages
- 11
Hey, I've skimmed this board a bit over the last few years but only just signed up. Quite a bit of good stuff going on here by the looks of it.
Anyway, a guy has just dumped this 747 in my lap for repair, apparently they've tried getting schematics from Avalon but had no luck so far. I've contacted the distributor today too but I'm not holding my breath for a schematic to show up in my inbox, I figured I may as well start hitting the web looking for answers. Basically there's a couple of transistors and zeners fried which are straightforward, but one resistor was so burnt that I couldn't read the bands on it (it crumbled to pieces as I removed it too so I couldn't even try to clean off the scorch marks). Just wondering if anyone here either has the schematic for the power supply section or has a unit and is able to check the value for me? It's R10 on the power PCB.
Also, I wouldn't mind double checking what Q1 and Q4 are supposed to be as there were a couple of transistors bodged in there with leads twisted around and tubing to stop them shorting, I'm not sure whether Avalon stuffed up the pinout/changed transistors during production or if somebody has had a crack at this before I got it and put in different/wrong transistors.
Cheers, hugely appreciate if anyone can help me out with some answers
Anyway, a guy has just dumped this 747 in my lap for repair, apparently they've tried getting schematics from Avalon but had no luck so far. I've contacted the distributor today too but I'm not holding my breath for a schematic to show up in my inbox, I figured I may as well start hitting the web looking for answers. Basically there's a couple of transistors and zeners fried which are straightforward, but one resistor was so burnt that I couldn't read the bands on it (it crumbled to pieces as I removed it too so I couldn't even try to clean off the scorch marks). Just wondering if anyone here either has the schematic for the power supply section or has a unit and is able to check the value for me? It's R10 on the power PCB.
Also, I wouldn't mind double checking what Q1 and Q4 are supposed to be as there were a couple of transistors bodged in there with leads twisted around and tubing to stop them shorting, I'm not sure whether Avalon stuffed up the pinout/changed transistors during production or if somebody has had a crack at this before I got it and put in different/wrong transistors.
Cheers, hugely appreciate if anyone can help me out with some answers
