K200 B1 popping fuses [message #28204] |
Tue, 04 May 2021 08:51 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
DocWaxham
Messages: 46 Registered: October 2018
|
Member |
|
|
Just got this and started fixing it up. It was filthy so I cleaned it all. Took power transistors out so they would'nt get soaked by cleaning. Checked the Pt's and all were good. Found a ballast resistor with broken lead fixed that new three prong. DE ox all boards. Replaced 10k pot. Fired it up and popped the fuse. I did not fire it up before doing all this because of the shape the power cord was in. Kinda scratching my head now. Ant help will be apreciated. Thanks.
|
|
|
Re: K200 B1 popping fuses [message #28205 is a reply to message #28204] |
Tue, 04 May 2021 11:42 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
stevem
Messages: 4758 Registered: June 2004 Location: NY
|
Senior Member |
|
|
I can't see why you pulled out the 4 output Transistors just to spray things clean, but I bet that when you reinstall them that was the cause of your popping fuses issue, assuming that you put the slip on connectors back on right.
One easy test is to remove the slip on connectors and ohm test the red wire and the both the Emitter and Base lead to ground, you should not see any low resistance reading.
A low reading on the red wire means that the case of the Transistor is shorted to the chassis.
Are the leads to the bias tracking diode in the clip between the output Transistors?
The leads break easily and if that circuit goes open the amp will pop fuses also.
To save you power transformer from harm until you get this issue cleared I would only do test with a 1.5 amp fast blow fuse in the amp.
[Updated on: Tue, 04 May 2021 12:01] Report message to a moderator
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Re: K200 B1 popping fuses [message #28241 is a reply to message #28204] |
Fri, 04 June 2021 05:58 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
stevem
Messages: 4758 Registered: June 2004 Location: NY
|
Senior Member |
|
|
First off as long as the amp is unplugged from the wall outlet you do not have to drain out the filters as there's only 40 volts sitting on them and that amount will not harm you unless you put your tongue across the terminals!
Also driaining any power supply filter out by just shorting them to ground can damage them as they need to be drained out through a resistor slowly.
These amps are not easy to work on since most everything is on that one main board that hangs off of the face of the amp, so things have to taken apart enough to get that board out and well clear of the amp.
If your ok with digging into the amp that far then we can continue, if not thent take the amp to a repair tech, and preferably one that does audio repair and is good with SS amps and not just a half Assed tube amp guy!
|
|
|