Failed Final Voltage Check

[Paul Birkeland]

The wattage of the 220 ohm resistor is not particularly important. 

[Dhouse7516]

Hi all,

A follow-up. I basically re-soldered and rebuilt the A regulator side of the shunt board (new RC, R3 and R4, new capacitor, and new regulator - which was shorted), and am now getting the following readings:

IA: 267
IB: 267
OA: 267
OB: 220
KregA: 1.88
KregB: 3.5

Any thoughts? Thanks much.

[Paul Birkeland]

I think I would just send this in for repair.  There is likely something else at work here that's causing all these problems that will probably be rather difficult for me to track down, but nearly impossible to detect over the forum.  You can contact queen(at)bottlehead(dot)com to request a repair box, and be sure to post a link to this thread and let her know that we have worked on this for a bit. 

[Dhouse7516]

Okay. Thanks, Paul. I will reach out to Eileen.

[Dhouse7516]

One final question before I send this in. I noticed that the 220K ohm resistor at R4 on the A side was only measuring at 69K ohms, so I replaced it with a new one. The new one measured fine at the lower R4 and Breg pads, but as soon as I connected it to the +Reg pad, it dropped to 69K ohms. I then checked the resistance of the 225K poly capacitor, and it was also 69K ohms, so obviously bad. Do you think it's worth it for me to try replacing the cap before sending this in, or is the failed cap most likely a symptom of a larger problem? If there's a chance this might solve the problem, I would like to try before paying for repair, but not if you don't think it lead anywhere. Thanks again for all of your help and patience. This is my third BH kit, and the only one I've had trouble with!

[Paul Birkeland]

There's something else going on.  You'd be the only person in the history of the company to have a cap short like that, so I would suspect something else is at work.

[Dhouse7516]

Haha. Well, I would hate to hold that ignominious title. In any event, the solder pad at +Reg for the R4 resistor just came off, so it's clear I'm just doing more damage at this point. I have connected with Eileen and will send this in. I am not going to bother soldering the new R4 back in, but will include it in the box. Thanks much, Paul.

[Dhouse7516]

Well, I should have checked this earlier, but I just tested the MJE5731 on Side A, and it's shorted. I am guessing that this is the problem. Unless, you disagree, I am going to swap in a new one and re-test everything.

[Paul Birkeland]

That will certainly cause some problems.  Usually those short from excessive voltage, and there isn't enough voltage in an Eros to do that, but it's worth a shot.