TCA9555 port 13 defect ?
Posted: 23 Jan 2023, 14:42
Today I found a new mistake on my CLASSIC RF Board, wich was brand new.
Port 13 from the TCA 9555 - its for the 10m TP Relais - does not work.
On port 13 ( TCA9555) there is a constant voltage from 1,6 Volts DC.
All the other ports from the TCA955 ( 11, 12, 14, 15 ) are with 0 Volt DC.
When I put the Scope probe to the Ports 11, 12, 14, and 15 (TCA9555)
I could see on the Scope short Pulses from 0 up to 5 Volts , by BAND change with Encoder.
Only on Port 13 was the constant 1,6 DC Voltage and on top of this 1,6 Volts a short puls up to 5 Volts.
BUT the RELAIS , here for the 10m LP Filter does not work . I could not hear any Relais click.
So think this 10m Latchrelais does not work .
Its well soldered.
And .... if the TCA9555 device would be defect , I think it was very difficult to get a new one
and its difficult to solder a new one on the board.
very sad.
hellmuth , df7vx
Port 13 from the TCA 9555 - its for the 10m TP Relais - does not work.
On port 13 ( TCA9555) there is a constant voltage from 1,6 Volts DC.
All the other ports from the TCA955 ( 11, 12, 14, 15 ) are with 0 Volt DC.
When I put the Scope probe to the Ports 11, 12, 14, and 15 (TCA9555)
I could see on the Scope short Pulses from 0 up to 5 Volts , by BAND change with Encoder.
Only on Port 13 was the constant 1,6 DC Voltage and on top of this 1,6 Volts a short puls up to 5 Volts.
BUT the RELAIS , here for the 10m LP Filter does not work . I could not hear any Relais click.
So think this 10m Latchrelais does not work .
Its well soldered.
And .... if the TCA9555 device would be defect , I think it was very difficult to get a new one
and its difficult to solder a new one on the board.
very sad.
hellmuth , df7vx