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Messages - Hawk

#2
Opto installed. All is well!

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#3
Thanks Enzo. I've ordered a new one. Hopefully it's the problem... haven't had any experience repairing these so first time for everything

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#4
Definitely not seeing a light. Tried adjusting the intensity and nothing. Measured 68k not 1 meg...the plate end of the 10meg resistor  measures 190v whereas the layout shows 380v...the 10 meg is good and the voltage on the other side of the 10 meg is good...does a faulty opto effect the plate voltage?....I checked the resistance on the lightbulb side and found 13 Megohms...

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#5
Can't see a light. Should it be fairly obvious?

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#6
According to the layout the voltages are correct on the "diode" side of the opto...there appears to be a resistive element in the opto, anyone know what value that should be?...

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#7
Vibrato not working..can hear a very feint ticking sound. Suggestions?

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#8
The springs had loosened so the suspended piece was banging against the side of the case and springs were not parallel to the bottom of cab. I fixed that. Also moved the pan as far away as possible from pt...it sounds pretty good considering its age. Thanks!

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#9
I'll try that tomorrow and reply. Thanks

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#10
I replaced all the caps...tank doesn't like power transformer? I moved the pan away from pt as much as possible and it reduces the hum some but there is still a hum after each note played but then the hum dies off after 1-2 seconds

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#11
Got reverb working...one of the big plastic ends that hold the two springs had literally come off its mounts and the two springs were coiled in wierd positions...so it sounds great but not for long as this hum develops and gets louder and louder  until I have to turn the amp off!   Suggestions??

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#12
Ran a signal through amp and used scope. See pic. The top reverb tank connection (reverb input)revealed a signal, but no signal on bottom lug(because it's a braided cable?). Also no signal on the two lugs on the output section of reverb tank. Pic isn't the greatest... thanks...so tank is shot?....Also, is the braided cable simply for shielding?....wow, this is an old reverb tank!

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#13
Tubes and Hybrids / Gibson Maestro Reverb Issue
May 08, 2018, 10:34:37 AM
Reverb is very weak or non-existent, hard to tell. Cable checks out. Amp works otherwise....Reverb pot has none or very little effect...reverb pot checks out okayhttp://cloud.tapatalk.com/s/5af1b3de20ea5/ga1rt%20%281%29.pdf

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#14
Thanks g1... I'm relieved hearing that.

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#15
Great articles. I had no idea. Learning a lot.Thank you! Under the resistors are 4 ceramic disc caps that have been flattened. I would have to remove the resistors to get at these caps to check them...do these have a history of failing? They are old...also anyone suggest a good pair of long skinny snips to snip these resistor leads?

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