BeePre resistance issues

[joepiecuch]

Finished (I thought) assembly on a BeePre and in checking resistances found a few things that concerned me. Reading related forum posts suggested that many of them are not indicative of anything significant, but there are a couple that seem to solidly point to something out of whack.

Terminal 28: i'm getting 400K to 600K readings rather than 0. I've examined and reflowed everything seemingly associated without change.

Terminal 19: stable reading of 427K w/o tube; terminal 4 is unstable w/o tube as suggested by manual.

Terminals 6 and 11: spec is 'more than 30K'; they both are that but 6 is 145K and 11 is 445K. Is this discrepancy a concern?

Any suggestions for how to proceed would be much appreciated. Thanks,


   

[Paul Birkeland]

Terminal 28: i'm getting 400K to 600K readings rather than 0. I've examined and reflowed everything seemingly associated without change.

Terminal 28 goes up to Neg In on the filament supply PC board, then travels to the Neg Out terminals that are bridged to -Reg.  All of these should show 0 ohms to ground and you shouldn't turn your BeePre on until this issue is remedied.  I would suspect there's a broken wire or that the jumper between Neg Out and -Reg is missing.

Terminal 19: stable reading of 427K w/o tube; terminal 4 is unstable w/o tube as suggested by manual.

This is another symptom that confirms the issue you have with terminal 28.

Terminals 6 and 11: spec is 'more than 30K'; they both are that but 6 is 145K and 11 is 445K. Is this discrepancy a concern?

This is yet another suggestion that there's a grounding issue on that side of your BeePre.  Do feel free to post some build photos and we might be able to spot the issue.  Just remember not to move on to voltage checks until we help you get these discrepancies resolved.

-PB


 

[Doc B.]

Hey Joe,

We have a lab for about one or two more days before we move it to temporary storage for a while. If you don't get it figured out and can come by on Monday I can have a look at it for you.

[Deke609]

Hey Joe,

where you goin' with that amp in your hand?

Couldn't resist. I'll show myself out.

[joepiecuch]

Thank you, Dan; I have the day off tomorrow, so that will work if necessary. I'm about to post some photos and hope to sort it out today, but will come by tomorrow if it comes to that!

[joepiecuch]

Thank you, Paul. Assumed it was prudent to sort out resistance issues before applying power! The jumper is there; all mentioned points have similar readings...well in excess of 0. Attaching photos; not sure these will be useful, but this phone camera is all i got.

[joepiecuch]

Two more.

[joepiecuch]

Last two.

[Chris65]

You have a mis-wire on the filament board, red & black wires transposed.
Should be: red wire to +reg, white wire to Kreg and black wire to -reg.

[joepiecuch]

Why, so I do. I had a suspicion it would be something obvious and right in front of my face. Thank you for pointing it out. Switched the wires and it now checks out. Thanks!