Hello everybody, i purchased a used orion 2150sx a couple of weeks ago and just found out that several of the output transistors (BJTs) and one Supply FET are kind of exploded. There are no burn marks on the PCB. I followed the threads about Orion Repair on this site with great interest and was wondering if somebody could help me with a schematic, otherwise i'll have to draw it from scratch which looks like a lot of work (double sided PCB and no part numbers - no fun).
Any help is greatly appreciated.
best regards,
Robert
Any help is greatly appreciated.
best regards,
Robert
It's unlikely that you'll need a schematic diagram to repair it. Replace the components that you know are defective (and those in parallel with those parts) and troubleshoot from there.
That's one possibility, i just have the "feeling" of flying blind and if the repair gets probably more complex the time searching quickly outweighs the time "making" a schematic diagram and understanding all the parts (or modules) of the system.
Anyway, does anybody know if the BJTs are matched together, meaning should i replace all transistors or just the broken ones?
Anyway, does anybody know if the BJTs are matched together, meaning should i replace all transistors or just the broken ones?
You have to replace all that are connected in parallel with the ones that failed. The replacements that are connected in parallel need to be from the same batch (matching date code).
Thanks. I am searching for a distributor and tomorrow i'll probably check the amp. The weird thing is, it is powering up, Rail voltage is fine, idle current too. Did not check the audio channels though. I am quite confident ther is not much more than the BJTs.
I'd suggest buying 10 each of the MPSA06, MPSA56 and 10 ohm, 1/4w resistors. Those often fail when the power supply FETs fail.
You gotta love orion amps. Finally finished drawing the schematic and started testing. In the PSU Section one driver is blown and in the amp section, Right channel, four 2n6488 and four 2n6491 are blown and the amp works like nothing happened!
Looked on the scope and everything is peachy.
I have a spare SMP60N06 and start ordering 6488 and 6491.
BTW: It could be of interest that Orion replaced the CEN-U07 / 57 Drivers and Pre-Drivers with 2SA1306B and 2SC3298B.
Looked on the scope and everything is peachy.
I have a spare SMP60N06 and start ordering 6488 and 6491.
BTW: It could be of interest that Orion replaced the CEN-U07 / 57 Drivers and Pre-Drivers with 2SA1306B and 2SC3298B.
You can't replace only one power supply FET unless it's closely matched to the others.
The CEN-U07/57 are not pin for pin compatible with the transistors you listed so they are not a drop-in replacement.
The CEN-U07/57 are not pin for pin compatible with the transistors you listed so they are not a drop-in replacement.
I beg to differ. For switching applications with MOSFETs there is no matching necessary (IMHO). For linear applications it is a different story.
The CENs are indeed not pin compatible. Orion must've changed the Layout then.
The CENs are indeed not pin compatible. Orion must've changed the Layout then.
While i value your experience and your support, i just have five of the SMP60N06 left and they are hard to find. I guess i could switch to IRF1010E, but then i have to change all twenty, otherwise the transformer will probably saturate due to asymmetrical excitation (is that the right word?).
Unless you can point out a source for ten SMPs (for a reasonably price) i'll have to risk it.
Unless you can point out a source for ten SMPs (for a reasonably price) i'll have to risk it.
If this is your amp, you can change only one. It may survive. If you're repairing this for a paying customer, replace all of the FETs in the power supply where one failed.
I use the IRF3205s in these amps when I repair them. I don't know what you have for suppliers in your area but the 3205s are inexpensive. Here, you can buy them for less than $1 each.
It shouldn't take more than about 15 minutes to replace all of the FETs in one supply. Removal is easiest if you do it as shown in the following video. It's best viewed if you right-click and save the link to your computer, then view it.
http://www.bcae1.com/temp/removingpartsfromolderorionamplifiers01.avi
I use the IRF3205s in these amps when I repair them. I don't know what you have for suppliers in your area but the 3205s are inexpensive. Here, you can buy them for less than $1 each.
It shouldn't take more than about 15 minutes to replace all of the FETs in one supply. Removal is easiest if you do it as shown in the following video. It's best viewed if you right-click and save the link to your computer, then view it.
http://www.bcae1.com/temp/removingpartsfromolderorionamplifiers01.avi
I can get the IRF3205s for about €2.- but the have twice the current capability and less then half of the RDSon, isn't that overkill? I guess you can omit five per side and it would still be more reliable than the SMPs.
Anyway, it is my Amp and i don't plan on selling (i currently have three 2150SX and one 2250XTR) 🙂
BTW (offtopic) anybody know Orion EU2700? Is that anything like the 275sx for example?
Anyway, it is my Amp and i don't plan on selling (i currently have three 2150SX and one 2250XTR) 🙂
BTW (offtopic) anybody know Orion EU2700? Is that anything like the 275sx for example?
I checked and the price I paid on the last order was $0.52 each. If the drive circuit can handle the load, there's no reason not to use them, especially when they cost no more than the original parts.
You probably noticed that this amp is PAM, not PWM. This means that the FETs will run hotter than PWM amps. Having a bit of extra capacity helps make the amp more reliable.
You probably noticed that this amp is PAM, not PWM. This means that the FETs will run hotter than PWM amps. Having a bit of extra capacity helps make the amp more reliable.
So i checked again and it seems one of the driver BJt is busted (2SA1306B). Anybody know where i can buy two or four pairs (NPN is 2SC3298B)?
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