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Title: Problem with a build...fixed and some photos Post by: RichardG on January 31, 2010, 07:50:07 AM I just built a ceriatone 18 watt TMB.
Plugged it in worked great. Cranked it up and the sound started dropping in and out, then it stopped, then a electronics burny smell. I figured out that the he1K5 5 W Resistor that runs across the 32uF/32uF was burnt out. I had another one the same so I soldered it in and the amp works again. BUT..... It is showing the same symptoms as before.....If I crank up the sound cuts out, so I have turned it off so I do not cook that resistor again. Seems OK at low volumes but I do not want to push my luck by testing it for an extended period. I did take it to a tech prior to turning it on just so he could check it over, so I am 99% sure it is wired fine. Any suggestions would be appreciated. Thank you. Title: Re: Problem with a build...can anyone point me in the right direction Post by: cmoore on January 31, 2010, 09:24:08 AM Can you take some voltage readings with all the pots on Zero, the Trem turned off, and the power tubes out of the chassis? It could be a lot of things, including bad power tubes. You can put the power tubes back in and see if your volt readings change.
Do you have a light bulb limiter? Title: Re: Problem with a build...can anyone point me in the right direction Post by: RichardG on January 31, 2010, 10:02:22 AM Can you take some voltage readings with all the pots on Zero, the Trem turned off, and the power tubes out of the chassis? It could be a lot of things, including bad power tubes. You can put the power tubes back in and see if your volt readings change. Do you have a light bulb limiter? I can do that. No I don't have a bulb limiter.... I probably should make one. Thanks Title: Re: Problem with a build...can anyone point me in the right direction Post by: RichardG on February 04, 2010, 11:12:44 PM Fixed, bit thought I would post in case anyone is interested.
After much rooting about, it turned out to be a bad power tube. I should have checked tubes first, but in my mind the problem was presenting like a bad solder in the power section or something like that. here are some gut shots I took for Nik. Its not tidied up yet as I was waiting until I fixed the problem http://picasaweb.google.com.au/cashmeuppawnbroker/GutShots# and here are some progress photos I was doing as I went http://picasaweb.google.com.au/cashmeuppawnbroker/Marshall18WattBuild# |