You have to be careful with those double sided boards when replacing parts.
I snagged a hr 2600 one time for cheap at the flea market.
The guy had a bunch of random electronics and in the mix i see this old hr2600 box.
I asked what's that?
He says it is a CB, he did not know anything about it and he would take $25.
I opened the box to look at the radio, its clean and then I see there is a black ChipSwitch box in the bag with the mic/mounting bracket and power cord.
I thought ok, this might be interesting.
How bout 20?
Deal.
Got to the car, opened the chipswitch box to find the stock 2600 cpu.
Drive home,
pull the cover off and there is a socket installed but no chipswitch.
Oh well.
Then I started looking at the cpu in the box and I could actually see 3 pins that still had the tiny through hole sleeve soldered to the pin.
Someone had pulled them out of the board when he removed it.
I removed the socket , put the CPU back in and made sure to flow the top/bottom of those 3 pins well.
Radio fired right up and everything functioned.
If not for that old chip I would not have noticed those pins.
Also glad I did not go down that rabbit hole...
THAT would be a much easier solution than hunting for a bad pass through......
73
Jeff