Crate palomino v32 V1 tube not lighting up help

[tonefiend]

Hello,

I have a Crate Palomino V32 2x12 amp where V1 in not lighting up. Any help or suggestions as to what to look for would be greatly appreciated, Im thinking the heaters some how arnt getting power, but im not sure what to test,

fyi: I have tested and put known good tubes in V1, so I have eliminated the possibility of a bad tube.

here is a copy of the schematic in .pdf form

Any and all input would be greatly appreciated,

thanks very much

[Chuck H]

The filaments look to be a simple AC parallel circuit. If one tube isn't lighting it's either the tube or the trace, wire or pin socket leading to the tube. If something were wrong with the filament supply none of the tubes would light. So start by replacing the tube and see if a different one works. If not you'll need to trace the circuit toward the supply until you find voltage. That's where the open circuit will be.

[Jazz P Bass]

Is there anything else wrong with the amp?

What an odd heater supply.

V1 A uses wire F2NC (AC voltage) (Pin 9) & -12.9 Vdc (Pin 4)
V1B uses F2NC (Pin 9) & Ground (Pin 5)

V2A uses F1NOT2 (AC voltage) & +12.9 Vdc
V2B uses F1NOT2 & Ground.

[52 Bill]

V1 A uses wire F2NC (AC voltage) (Pin 9) & -12.9 Vdc (Pin 4)
V1B uses F2NC (Pin 9) & Ground (Pin 5)

V2A uses F1NOT2 (AC voltage) & +12.9 Vdc
V2B uses F1NOT2 & Ground.

F2NC is not connected to anything, so the filaments are series connected and dc powered by the -12 volt supply. F1NOT2 is also floating so the tube is powered from the +12 volt supply.

Exactly which tube is not lighting up, J1 a preamp tube or one of the outputs? There is no V1 in any of the documentation.

[Jazz P Bass]

There is no V1 in any of the documentation.

Caught me.
All tubes are labeled 'J'.
Sorry for using the standard nomenclature.

[52 Bill]

Caught me.
All tubes are labeled 'J'.
Sorry for using the standard nomenclature.

Not you, the OP started with the V1. The OP may or may not be talking about J1, as he didn't tell us what kind of tube he discussing.

[Chuck H]

Aaahh. I scrolled down and looked at the filament supply and then scrolled up to see that the PI and power tubes were wired in the typical way... Then I just closed it and wrote my post. Oops.

I don't see how any series connection is indicated though.?. And I suppose that would be supported by there being only one tube that isn't lighting up. I see the OP edited his post to indicate that a good tube was tried.

Since the OP is using the term "V1" instead of the schematic designation I have to assume they know the typical blanket application for that term. So that would be the first preamp tube. I'll stick to my original suggestion that there is an open circuit in the filament supply leading to that tube.

[Jazz P Bass]

Well, one of the things to check would be the +12.9 & -12.9 Vdc supplies.

[tonefiend]

Hello sorry for the delay, I did finally figure it out and fix the problem. So the heater was out on tube J1, which I would usually call V1, but in crate world they call it J1. The tube did not light up in that tube socket only, so I knew it wasnt a bad tube. after going through the circuit board I noticed that the nut that holds the jewel light in place had slid off and was sitting on the mother board, right next to R50... hmmmm after closer examination R50 looked charred, hmmmm after another looksie, one side of R50 was not attached to the solder pad on the circuit board... very bad. I tested the resistor which was ok, still in spec, and resoldered it back into place... and low and behold J1 is back in order, amp sounds great... of course i had resecured the jewel light nut as well. Now im doing the resistor mod, to cool things down in there. which is a well known mod that needs to be done to this amp.

anywho, thanks for the replies,