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Orange Rocker 30 Head Case
Hi Guy's!!! Got a Orange Rocker 30. Turned it on last night and had a blue flash come from the back wich resulted in a blown power tube and fuse. I replaced the tubes and fuse's. Now everything lights up and comes on , but no sound from the amp. I took it apart and it shows no signs of obvious problems , like shorts or fried components. Is the output tranny blown?
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Doubt it but it is quite easy to check for a quicky. Locate the Primary Output Tranny wires and with the meter set to ohms (amp off of course) check from usually the red B + wire to each side usually blue and brown going to the tube plates. Ohms should be equal from C (B+) to each side
Also look around for some fuses inside (HV Supply) that may have blown and replace them if they are blown.Also check out RG's site for OT check if you can't find the wires.
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When I place the neg on the output wires of the amp and the + on the tube sockets the needle jumps a little and dies back down.Comment
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That is the secondary side and has no effect on telling if the tranny is good or bad with that check. Did you find any other fuses inside. I highly doubt the transformer is bad and at worst possibly a blown screen resistor.KBComment
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I have found that every time I go from standby to On it blows the ht fuse. Checking screen resistors now.Comment
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it blows the fuse regardless. without tubes or with. I am not sure if I'm checking the screen resistors propperly. Orange want $45 dollars a hour to fix it plus parts/shipping both ways. I'm thinking this might come to that.
I'm still ope to suggestions. please keep them comin.
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Unfortunately that's more than the amp by the time you're done. You don't have a tech around there ? The screen resistors are either 100,470 or 1k. Can you get a schematic and which tubes do you have ? I'm thinking EL-84's.
Oops ok I remeber these and worked on one. EL-34's pretty nice tone. The screens should be 1k 5 watters and located on pin 4 of the sockets.Last edited by Amp Kat; 01-28-2010, 10:12 PM.KBComment
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There is a tech around, but they are $75 a hour and 2 month wait. I'm gonna take the board out and see what I can find. I'm wondering if there is any carbon arcing on the bottom side of the caps or resistors. I have built a few amps and have a little bit of smarts. But diagnosing problems and building fron nice new parts are very different I'm finding
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Yeah you're right but keep us updated on what you see and we'll help you find what is causing the short. It's good to do a visual inspection and when tubes short they can take out traces underneath. Usually the fuse blows first but sometimes they don't. Let us know.KBComment
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Did you try taking a resistance reading from the standby switch secondary to ground?
Maybe you can find a low resistance path (short) at the transformer or the filter caps or somewhere else.Comment
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I called Orange and got a RMA# from them. I'm sending it back as soon as the Oklahoma ice-pocalypse is over. I want them to fix it and install MM tranny's in it. I don't really have any money up front in the amp(traded a guy another amp I never used) so I can live with a freshly re-built rocker 30 for a little scratch. I really like this amp or I would'nt mess with it. I will tell you all what they say as soon as I hear from them. Maybe a few weeks.
Thank all of you for the help. I greatly appreciate it.
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