Orion 420gx

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I bought this amp of a guy for 40 bucks and he said it didn't work. I can't find mention of this amp ANYWHERE. It's like it doesn't exist but I'm holding one. Anyone got any info on this thing? 4 channel x 20 watts per I take it. Did Orion only kick out a small number of these things? Just wondering if any of you have any background info on it. I like to read up on certain amps and Web searches came up empty.
 
Hi,
in Italy we have had this amp around since 1991 and furtherly a couple years at least, and it's been tested on a magazine.., deep switches inside on m.b. are critical for 420GT to correctly working....what's the problem with yours one? I see you did not reply to Perry an Crash posts...
 
I just got around to opening this thing up. First class A/B amp which uses MOSFETS instead of normal transistors that I have worked on. It uses IRF9540/IRF542 pairs. It looks like one of the 9540's shorted taking the power supply with it. All 4 SMP60N05's in the PS were shorted as well. The drivers for the power supply FETs look OK but the 10 Ohm resistors feeding those drivers burned and they went out of tolerance. Going to replace all those parts and see how it goes. For some reason I'm thinking that those 60n05s are no longer made and it's going to be a pain finding them but I may be mistaken.

The bottom of the amp has a sticker which shows you what the DIP switches do so I should be OK setting them.

I attached a couple photos for those interested.
 

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First class A/B amp which uses MOSFETS instead of normal transistors that I have worked on. It uses IRF9540/IRF542 pairs. It looks like one of the 9540's shorted taking the power supply with it. All 4 SMP60N05

Hi,
I see you're on the repair-road... ( it did not work, really) and you did overview the failing parts.. you sure did mean IRF540 with 9540, while the power supply FETs I have found in it are SUP60N06 and I guess they are same as SMP60N06, Vshay brand made and should be easy available, other ways you may try with STP60N06 or any by Fairchild or by ON.

Let me join Cr@sh best wishes for your goal repair!
.
 
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