How to test a UA7805CKCS component

[roadrash]

How do I test a UA7805CKCS which i believe is a type of voltage regulator. My component tester has a problem with it for some reason so I need another was of testing it with a multimeter if that's possible.

[llonen]

Re: How to test a UA7805CKCS component

Looking at the device schematic its a voltage regulator on a chip and quite complicated, your probably better removing it and testing with and psu and measuring output properties. Or simply replace the device as they are very cheap to buy, what is the rest of the circuit doing or not doing and can you post pictures please.

[budm]

Re: How to test a UA7805CKCS component

How do I test a UA7805CKCS which i believe is a type of voltage regulator. My component tester has a problem with it for some reason so I need another was of testing it with a multimeter if that's possible.

1) You cannot use your component tester to test Vreg IC.
2) With the device still in place and no power applied, check the resistance between GND pin and the Input pin, GND and the Output pin. If the resistance shows <10 Ohms or so then you may have problem.
3) Apply power to the board and check the Voltage between GND pin and the Input pin, between GND pin and the Output pin. Notes: the input Voltage should be about 3 ~ 5V higher than the Output Voltage spec, in this case it is 5V regulator so the input shout be around 8V or so.
https://cdn.badcaps-static.com/pdfs/...ff905ce490.pdf

[R_J]

Re: How to test a UA7805CKCS component

A quick way, use a 9v battery between ground & input, check for 5v output between ground and output pin.
better test use a 9 volt input, + to in, - to ground, on the output connect a 10Ω 3watt between ground & output with a .1 ~ 10µf across the resistor, this will test the regulator at 500ma

[roadrash]

Re: How to test a UA7805CKCS component

Thanks that very informative and interesting info everyone its a great help. This comes out of a 1980's vintage Apricot keyboard which has been giving me some problems. I recently bought 5 of them as you say they are cheap. I was just interested in why i couldnt test it. Many thanks.