Bottlehead Kits > Kaiju Stereo 300B amp

Issues with driverboard testing [resolved]

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ericoto:
Working on Kaiju all testing previously was fine after wiring driver tubes and installing cs4 boards all readings off, both sides A side LEDS not lighting, B light fine, voltages about 233-235 at IA and OA respectively. Initial reading at 36 and 46 fine at 175. Any help suggestions appreciated

Paul Birkeland:
You will need to slip one wire out of one IA pad, then fire the amp up to see if the other IA pops up.  If it doesn't, then trade which IA wire is connected and which isn't, then recheck.  When you find which board is pulling down the high voltage rails, remove it and post more photos of the top and bottom.  Also post photos of the string of zener diodes mounted to the 5 lug terminal strip on that side of the amp.

-PB

ericoto:
Well I tried it an neither side corrects, still reads low about 240V, noted that voltage at 14 is also down at about 240V  I have rechecked board construction and wiring no obvious errors, High voltage checked fine in preceeding tests

Paul Birkeland:
The red wire from one of your plate chokes is not attached and soldered where it's supposed to be.  It's probably trying to short out the high voltage power supply to the chassis.  I would correct that mistake, then with the amp off, unplugged, and discharged, be sure that the DC resistance between the blue and red wires on each plate choke is still roughly the same.  If the plate choke on the offending side has dropped substantially in resistance, you will need to remove it and purchase a replacement.

ericoto:
Thank you for getting back to me so quickly. I did recheck the choke connections, they appear to be in the right place 35L and 43L, I desoldered both and then resoldered. I still have the same issues, the voltages are low around 240 in both IA as well as OA. The resistance is to both chokes is also the same approximately 485 ohms Should anything else be attached at these points? Also I have 4 60 ohm resistors remaining I dont see where these ayyach. Thank you again for your help

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