Veraxis
Active Member
Hello all,
Whenever electronics break, or are destined to be thrown away, I will often take them apart and salvage components from the circuit boards, as I am sure some of you on this forum often do. While doing this, however, I have occasionally come across electronics that appear to have had changes made to their design after the manufacture of the PCBs. perhaps this is not all that uncommon, but it has always been something that I found suprising. For example: one of the first times that I saw this was in an old car radio, where the following part had been added:
**broken link removed**
The resistor was connected from part of a tuning circuit for the radio to a piece of metal casing, possibly even soldered in by hand, then covered over with epoxy.
It seemed odd to me that a commercially sold product from a brand-name electronics manufacturer would have a part added in that was not built into the circuit board, but I did not think too much of it until some time later, when I saw something similar in a small treble/base control board in a portable cassette player:
**broken link removed**
This time, there were holes marked of the other side of the board for where the resistors had originally been supposed to go, but it seems that they had been brought to the other side of the board and connected to different places.
One of the most interesting changes that I have seen, however, was this last one, from a portable transistor radio:
**broken link removed**
Whether due to an error in the manufacture of the PCB, or some sort of design error not noticed until the last minute, one of the inductors and one of the capacitors had been switched around, then glued together, and with another capacitor removed entirely, as is still marked on the silkscreen just to the right of the switched components.
My question to all of you is, why were these changes made in this way rather than sending back the circuit boards, and is this sort of thing common? how unusual is it for electronics manufacturers to have to make last minute design improvements, or to have weird workarounds for errors in the PCBs?
Whenever electronics break, or are destined to be thrown away, I will often take them apart and salvage components from the circuit boards, as I am sure some of you on this forum often do. While doing this, however, I have occasionally come across electronics that appear to have had changes made to their design after the manufacture of the PCBs. perhaps this is not all that uncommon, but it has always been something that I found suprising. For example: one of the first times that I saw this was in an old car radio, where the following part had been added:
**broken link removed**
The resistor was connected from part of a tuning circuit for the radio to a piece of metal casing, possibly even soldered in by hand, then covered over with epoxy.
It seemed odd to me that a commercially sold product from a brand-name electronics manufacturer would have a part added in that was not built into the circuit board, but I did not think too much of it until some time later, when I saw something similar in a small treble/base control board in a portable cassette player:
**broken link removed**
This time, there were holes marked of the other side of the board for where the resistors had originally been supposed to go, but it seems that they had been brought to the other side of the board and connected to different places.
One of the most interesting changes that I have seen, however, was this last one, from a portable transistor radio:
**broken link removed**
Whether due to an error in the manufacture of the PCB, or some sort of design error not noticed until the last minute, one of the inductors and one of the capacitors had been switched around, then glued together, and with another capacitor removed entirely, as is still marked on the silkscreen just to the right of the switched components.
My question to all of you is, why were these changes made in this way rather than sending back the circuit boards, and is this sort of thing common? how unusual is it for electronics manufacturers to have to make last minute design improvements, or to have weird workarounds for errors in the PCBs?