The regulator will only short once I apply 12v remote.
As for the rail caps I'm not sure but here are photos showing they are infact shorted. No volatge in the board when I took these photos and probes were on for a good 40 seconds before taking photo.
Please excuse the horrible photography it's hard to hold probes and take a photo
As for the rail caps I'm not sure but here are photos showing they are infact shorted. No volatge in the board when I took these photos and probes were on for a good 40 seconds before taking photo.
Please excuse the horrible photography it's hard to hold probes and take a photo
Attachments
I measured 38V on the output transistor.
There is only a short on the rail caps when power is in the board. It appears.......
I just removed the LM337 and my tester is saying it's faulty...
With power in the board I'm reading 38v on all rail caps... so I guess there not shorted....
I'll order this LM33 and see what it improves
There is only a short on the rail caps when power is in the board. It appears.......
I just removed the LM337 and my tester is saying it's faulty...
With power in the board I'm reading 38v on all rail caps... so I guess there not shorted....
I'll order this LM33 and see what it improves
Perry. On a class A/B. Should I be getting a pretty close match of positive and negative rail on the output transistors?
As I'm seeing -28vDC but only +3vDC.
As I'm brand new to class A/B I'm not sure if this is normal. I am getting audio out of the rear so suspect it may be normal.
I'm thinking I may pull all driver boards for the front channels and check components. Next to impossible to do with board attached.
My limited skill is suggesting there is a short circut on one of these boards.
Thanks 🙂
As I'm seeing -28vDC but only +3vDC.
As I'm brand new to class A/B I'm not sure if this is normal. I am getting audio out of the rear so suspect it may be normal.
I'm thinking I may pull all driver boards for the front channels and check components. Next to impossible to do with board attached.
My limited skill is suggesting there is a short circut on one of these boards.
Thanks 🙂
It's most definitely not common to have only one rail and especially only a negative rail. Use the secondary center tap on the transformer for the reference (black probe). You can also use the non-bridging terminals.
Are you checking for rail voltage on the output terminals of the rectifiers?
Are you checking for rail voltage on the output terminals of the rectifiers?
All testing has been done using my oscilloscope with ground on main input ground. DC coupling.
I did a small test with my multimeter just putting probes on the legs of the output transistors.
I'm just letting you know this info so that if anything I've brought up in this post may be attributed to having my scope ground on main ground.
On the rectifiers is the ground always the >[]< or <[]>? If you could help me with that question that may better help me find the centre tap of the transformers
Thanks perry
I did a small test with my multimeter just putting probes on the legs of the output transistors.
I'm just letting you know this info so that if anything I've brought up in this post may be attributed to having my scope ground on main ground.
On the rectifiers is the ground always the >[]< or <[]>? If you could help me with that question that may better help me find the centre tap of the transformers
Thanks perry
The secondary side of the transformer will be on the audio side of the transformer. The secondary has two bundles of wires of two different colors. Where those two colors are combined is the center-tap.
The attached is not an Orion but it's the same layout. Yellow and green windings on the outside (go to rectifier inputs) and the combined windings, which are the center-tap.
The attached is not an Orion but it's the same layout. Yellow and green windings on the outside (go to rectifier inputs) and the combined windings, which are the center-tap.
Attachments
Negative probe on here which is a direct connection to non bridged negative speaker terminal I'm now seeing both plus and minus 38v DC rails. On all output transistors.
I'm seeing what I would suspect as normal (ie) base collector and emmiter I'm seeing 0v base. 38vDC collector 0v emmiter. Or 38vDC base 0v collector 38v collector. So there are no voltages where there shouldn't be. In regards to output transistors
I'm seeing what I would suspect as normal (ie) base collector and emmiter I'm seeing 0v base. 38vDC collector 0v emmiter. Or 38vDC base 0v collector 38v collector. So there are no voltages where there shouldn't be. In regards to output transistors
