Moscode 300, cap blown?

kawizx9r

So, I've got a few questions actually to get this thread going and to obtain some vital information.
I have a Moscode 300 Hybrid amp that I'm using to power my SDA 1C's (150wpc@8ohms and can go as low as 4ohms easy). I spoke to the person I bought my Moscode from (and SDAs) and hes been more than helpful so I'd hate to bug him even more about a problem I have. I powered up my amp one day like any other day, and something started burning (smelled like plastic) and a little bit of smoke came out near the power switch. I quickly shut it off and disconnected it. I spoke to him about this and he said there's a capacitor connected with the power switch and it may have burned out or something, nothing big. I've done self repairs, have soldering experience etc but would replacing such an item still pose a huge risk being that it is a tube amp? Also wondering if anyone in the Chicago area knows and deals with a vintage stereo repair shop, or if they can do the work themselves? I love the amp and hate not being able to listen to my SDA's, and don't want to bother someone who's helped me more than enough, and maybe looking to find anyone with moscode experience, many thanks!

If you are local and think you can help me out in my situation, I'll be happy to go outta my way to drive to you. Rather deal with Polkies than have some random person at a shop poke through my stuff

kawizx9r

Was being a little vague about the information on repair shops. I meant any repair shops that have a good reputation and that you've personally dealt with?

AudioGenics

If you could isolate the capacitor that is suspect or 'de-solder' it
and test capacitance and if it is no longer any good that just may be the fix.

also check all the remaining components.
start with a thorough visual inspection.

A circuit diagram /schematic would be very helpful for test points and values.

kawizx9r

Yea, was just worried about actually working inside the thing. I know they can hold charges that can prove lethal, something you don't worry much about when dealing with computers/etc.

AudioGenics

found this information that sounds useful
there are additional precautions to be sure
protecting and isolating yourself ....

http://www.repairfaq.org/sam/captest.htm

Check with a electrical engineer / technical friend or professional.

kawizx9r

Thanks for this! Going to check it out

Systems

Small value caps are usually placed across power switches to eliminate switch bounce.If the switch is still good you can just remove the cap and your amp should function fine.Being as it's a small value, the cap will not hold a charge .

AudioGenics

i was reading the information myself

interesting that one comment...
..."We consider any electrolytic cap to be suspect if it's code date is over five years old"

warrants more reading.
thanks