Bad charge pump IC; you should be seeing
negative voltages on pins 4 & 5 of the 7660S and on pin 4 of the TL072 dual op amp. You should also see about +18V on pin 8 of the latter (my personal 27V Boost IC voltages are posted below). The voltage span between pins 4 and 8 on the op amp are why it's called "27V." Contact
sales@buildyourownclone.com and request a free replacement.
rg1820x wrote:
FYI: I was in the process of desoldering the footswitch when I took the pic . . .
As I'm sure you noted, that's a fairly large PITA to do. In the future, check in with us here before you start taking things apart in the pedal.
When you receive the new charge pump, don't try to remove the old one in one piece, which is similarly difficult. Instead, clip off the eight pins as close to the body of the IC as possible, then desolder them one at a time. Clean out the old solder from the eyelets with a solder sucker or desoldering braid and then install the replacement IC.
Attachment:
27V Boost IC Voltages.gif [ 4.59 KiB | Viewed 4329 times ]
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