DC offset issues - Help! - Dean GA40R

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I have a solid-state Dean GA40R guitar amp. When I turn it on with no inputs and all the knobs at 0 I get this huge hum/buzz coming from the speaker. The amp has been sitting for a couple of years and from what I remember, there used to be a pop or buzz sound everytime I turned it on for a split second. I don't know if that is useful information. When turned on the speaker only pushes out, which from what I have been able to gather online, means it has a DC offset. I have used a multimeter which for DC purposes can only read DCV (DC Volts) and DCmA (DC miliamps). From what I have read so far, DCmV (DC milivolts) is what I am trying to read. When I use the setting of DCV on my multimeter I get a reading off of the negative and positive speaker terminals of about 24 DCV. Would this be the the same as 2,400 DCmV? and if so, would this indicate a huge DC offset?

Also, I cant find any useful schematic info or user manuals for this amp. If anyone knows where to find some or has more info on it that would be great.

Once I figure out if this is a correct DC offset reading, where do I go from there on troubleshooting? I am pretty new to this, but am pretty interested in tinkering around with it, I have knack for repairs.

Any information is appreciated. Thanks!
24 VDC is 24,000mVdc

Your speaker may be permanently damaged with this level of voltage applied.

Disconnect the speaker and put in a 100W light bulb for a load until you fix it.

24VDC is not what I would call an offset issue...I would call it broken.

A schematic would really help and you may have to try to trace the circuit out to get an idea what it is supposed to be.

Or you could get the part numbers of all of the transistors and measure the voltages on them and see if the numbers make sense with how they should be hooked up.

Hope that helps a little.

I have a speaker of no use attached for quick on/off tests to see if the problem is still occurring.

Of the three transistors, I am only getting a reading from two. I am unsure of this reading because it spikes on my multimeter and sparks at the connection. Could the one transistor giving me no reading be the problem? or is it more likely that the underlying problem is whatever caused it to blow to begin with?

I have scoured the internet in search of a schematic. Are there any websites in particular that would be of aid?
Well, now when I turn it on after a second I get smoke from the middle control knob and from set of wires going to the line-out and external speaker inputs. This amp might just be near death or should be taken to a professional at this point I'm assuming.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.