Members jr_vw2 Posted December 28, 2007 Members Share Posted December 28, 2007 My 5150 is only running on two power tubes. The two outer power tubes are working fine but the two in the middle are not. With the two middle tubes removed there is no difference in sound and with ONLY the two middle tubes installed there is no output. I thought I might have some dead tubes so I just retubed the whole amp (including preamp) Is there anything that I can check? I would like to check all that I can before sending it to a tech. Thanks for the help. Link to comment Share on other sites More sharing options...
Members JerryP Posted December 29, 2007 Members Share Posted December 29, 2007 My first guess would be open screen grid resistors. Jerry Link to comment Share on other sites More sharing options...
Members jr_vw2 Posted December 29, 2007 Author Members Share Posted December 29, 2007 What should I expect to pay to have this fixed? I have never taken an amp to a tech, so I dont even have a ball park idea. THanks Link to comment Share on other sites More sharing options...
Members insurrection Posted December 29, 2007 Members Share Posted December 29, 2007 What should I expect to pay to have this fixed? I have never taken an amp to a tech, so I dont even have a ball park idea. THanks If in fact it is the screen grid resistors, then about 74 cents each if you buy them and solder them yourself. 50-100 dollars to have a tech do it. Link to comment Share on other sites More sharing options...
Members jr_vw2 Posted December 29, 2007 Author Members Share Posted December 29, 2007 If someone could help point me in the right direction I feel comfortable enought replacing them myself I am just unsure as to what resistors I actually need to buy. http://tubesandmore.com/ If someone could give me some specifics on what kind of resistors I need (if in fact thats what is is) I would appreciate it. Link to comment Share on other sites More sharing options...
Members insurrection Posted December 29, 2007 Members Share Posted December 29, 2007 If someone could help point me in the right direction I feel comfortable enought replacing them myself I am just unsure as to what resistors I actually need to buy. http://tubesandmore.com/If someone could give me some specifics on what kind of resistors I need (if in fact thats what is is) I would appreciate it. I don't know what the 5150 specifically calls for, but in most cases, screen grid resistors are 5watt, 1Kohm. The standard television style white ceramic box-type would work even. You'd have to hit up JerryP for specific info on the amp (if he's generous enough to take time out of his busy day to help you for free) like the resistor value as in case you haven't noticed, Jerry is the Peavey Pimp around this neck of the woods Now look man, one thing you've got to consider if you're thinking about doing it yourself is this; you can't just take the chassis out, flip it over, and start working. You have to discharge the filter capacitors first (the big, cylindrical structures that mostly have three contacts on the bottom, typically about 1.5 inches in diameter and 3 to 4 inches in height. You need to research it and figure out if it is something you're comfortable with doing. Then decide if it would just be worth the 50-100 bucks to have someone else do it and guarantee it to work again at least for a little while. Link to comment Share on other sites More sharing options...
Members JerryP Posted December 29, 2007 Members Share Posted December 29, 2007 The 5150 uses a 100 ohm 5 watt screen grid resistor. You can get them all over the place. Mouser is one good place. The bigger problem is you have to drill out the rivets holding the power tube sockets in to remove the circuit board to get at them. If a resistor or two failed you'll need a set of power tubes too. Jerry Link to comment Share on other sites More sharing options...
Members jr_vw2 Posted December 29, 2007 Author Members Share Posted December 29, 2007 Jerry I really appreciate you taking the time to lend your info. It is most helpfull, would you mind lending a bit of the specifics as to what type and what tollerances/temp rating...etc of resistors the 5150 uses. Thanks very much. Link to comment Share on other sites More sharing options...
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