Bottlehead Kits > Foreplay III

Extended FP III resistance issue [resolved]

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Neuronal:
Hi - after burning in my (newly built after all these years) FPIII for a few months I decided to install the extended upgrade. When I took resistances at the terminals, everything was normal. To be extra careful, I also read across all of the accessible resistors to make sure they were still reading correctly. Everything looks fine except for the B side 127 kOhm resistor on the shunt regulator board (light blue, on the lower left when looking at the flipped chassis with the volume pot towards me), which reads 82.3 kOhms, as opposed to the A side equivalent resistor, which reads correctly at 148 kOhms. When I read across the + and - terminals on the A side, I get 148 kOms, and when I do the same on the B side I again get 82.3 kOhms.

Is this a problem, and if so is it limited to that one resistor (or instead maybe I've messed up something that lives in parallel to that resistor)?; I haven't yet fired it up to take voltages, as I'm afraid of smoke given the strangeness.

thanks in advance for any advice or help- it is really appreciated!

Paul Birkeland:
The voltage divider that biases up the heaters sits across one of the regulated B+ rails and will throw off one of those resistances.  I would bet if you heat up and lift out one end of the resistor in question, it will measure perfectly.

Having said all that, if you have had this kit sitting around for 10 years, the probability that the included LEDs have absorbed too much moisture to be soldered is somewhat high. 

Neuronal:
Thanks Paul - I remembered your advice from before about old LEDs, and before the build I went ahead and bought 20 from the Queen.

I fired it up, and the tubes lit up. But now a new set of problems:

1. On the left, the A side C4S board LEDs light up; the B side does not light, but the LED soldered into the tube holder does light. On the right, no LEDS on either the A or B side, and the LED in the tube holder does not light either

2. Voltages (VDC) are really off. Power supply voltages (strips 1-10) are normal. But:

H1 - 4.5 V
H2 - 11.4 V
12 - 25 V
15 - 15 V
21 - 25 V
22 - 4.5 V
21 - 208 V
21 - 156 V

Any advice? I'm not sure where to start with this....

Neuronal:
Oh, and since I forgot to mention it, all the shunt reg LEDs light up fine

Paul Birkeland:
It would be far, far easier if I could have:

IA, OA, and OB for the two outside boards.

IA, IB, OA, OB, and Kreg for the middle board.

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