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Vintage threads from the first ten years

Laney problem

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4/20/2004 1:55 AM
km	Laney problem Got an amp today to troubleshoot-a Laney VH100R--it is blowing the HT fuse.-I pulled all the tubes and it still pops the ht.Heres the strange part--i have all of my voltages 6.3ac and 400vdc-etc...at the sockets with the standby switch in the off position(idle).... i checked the switch itself and its fine..Suggestions??

4/20/2004 1:59 AM
km	anyone know where i can find a scem for this online??

4/20/2004 11:19 AM
Guitar Tone UK	I don't know if Laney makes this generally available, but someone gave me the following link only with VC30.pdf at the end (for my VC30 doh). It also seems to work for VH100. http://www.laney.co.uk/html/Downloads/Services/VH100.pdf

4/20/2004 8:08 PM
Ian Anderson	Thanks for that link, I snagged the old Klipp schematics while I was there and also the one for the L100PA I'm working on right now, cheers!!! ... Ian

4/20/2004 10:12 PM
km	thanks for the scem--i tried something today--i unhooked one side of the choke and the ht fuse did not blow.I assume this tells me the problem is after the choke..but im not sure

4/22/2004 1:02 AM
km	today i found something strange--all of my voltages at the tube plates-pre and power --are ALL 444v.--all of them! looking at the schematic its obviously way off!-even on both sides of the choke its about 453 volts-same at the rect. output. according to the scem-theres a 25w 10k right after the choke--i think it could be the culprit?????however i cannot find the damn thing in the amp !!!

4/21/2004 11:27 PM
Shea	To me that suggests none of the tubes are passing any current, therefore the B+ voltage doesn't drop across the choke or the dropping resistors. I would suspect a bad ground. Does it make any sound? Shea

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