Hi,
my ugly but beloved Proton AM-656 is not working anymore. I suspect that the power on circuit has some problems.
Unfortunately the amp has a very complex power supply section, with three transformers and an indecent wiring style, so it's really difficult to perform a reverse engineering analysis.
Where can I find the service manual, or at least the schematics?
Many thanks in advance to everyone
my ugly but beloved Proton AM-656 is not working anymore. I suspect that the power on circuit has some problems.
Unfortunately the amp has a very complex power supply section, with three transformers and an indecent wiring style, so it's really difficult to perform a reverse engineering analysis.
Where can I find the service manual, or at least the schematics?
Many thanks in advance to everyone
You can buy the service manual as a download for about 15 Euros but as far as I know, that model was rare and few service techs will have a paper copy or computer file to upload - probably not for free or without some form of compensation, if that's what you were hoping for. You have probably seen this already but here is just one, typical online source: https://www.servicemanuals.net/en/PROTON-AM656-AM-656-Service-Manual
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Nice one, huggygood. As said - pretty complex and compact too. I wouldn't try fault-finding or repairing it without some related experience and decent test gear for support.
To Ian's point, do you have any test equipment and repair experience?
Not disputing your suspicion of power-on circuit, but can you provide details?
Thanks.
Not disputing your suspicion of power-on circuit, but can you provide details?
Thanks.
@huggygood
All these Protons seem to share the same topology (similar to the Hitachi latfet application note, but with BJTs instead).
Do you have by any chance the schematics of the Proton AM-20?
When I purchased mine in the 90's, it only came with a minimalistic user manual, which I uploaded to Hifiengine.
All these Protons seem to share the same topology (similar to the Hitachi latfet application note, but with BJTs instead).
Do you have by any chance the schematics of the Proton AM-20?
When I purchased mine in the 90's, it only came with a minimalistic user manual, which I uploaded to Hifiengine.
Do you have by any chance the schematics of the Proton AM-20?
I look when I have a moment and I tell you.
I look when I have a moment and I tell you.