TCA9555pwr ports defect

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hellmuth
 

Posts: 12
Joined: 14 Dec 2022, 13:59

TCA9555pwr ports defect

Post by hellmuth »

In the meantime I found a second mistake on the brand new RF Board with this TCA9555 circuit.

Port 15 for the 15 m Relais is also complett dead.

There is also all the time 0 voltage .
No puls, to switch the K2 Relais.

Because there is from my point view no possibility to remove the circuit and to get a new TCA9555 device
I think I must stop this nice qrp project .

I am very sad about that, but I do not have any Idea what to do.
hellmuth , df7vx
s57l
 

Posts: 56
Joined: 30 Dec 2021, 21:30

Re: TCA9555pwr ports defect

Post by s57l »

How about some solder bridges? It is very unlikely that they used half dead chip. Maybe relay problems?
Contact yor seller and return it?
73 gl
DL2MAN
 

Posts: 706
Joined: 30 Dec 2021, 19:18
Contact:

Re: TCA9555pwr ports defect

Post by DL2MAN »

Ask in your OV (local ham club) who has hot air soldering equipment.
This chip is very easy to change with this. I did not bother to ask, and invested the 50€ to buy my own....
Good investment in retrospective, as it is now also very easy to relpace ATMEGA Chips and SMT Crystals etc. And a replacement chip is cheap.
Not impossible, but a little harder: It can be changed with normal soldering iron and the right technique. But if you want to try it, try it with sacrificial hardware, because there´s a steap learning courve involved.

73 Manuel; DL2MAN
hellmuth
 

Posts: 12
Joined: 14 Dec 2022, 13:59

Re: TCA9555pwr ports defect

Post by hellmuth »

Ok Manuel, desoldering of the device would be not a problem for me.

The main problem would be to get a new one.

But the good news now: I have ordered today some of this devices called
PCA9555 24 pin SSOP Case from R-S Components .
There is no significant difference in function between TCA9555 and PCA9555.

But it was only possible to order this Circuit as a "Dealer". ( a friend here nearby did it for me)
For privat User / People it was not possible to get this integrated Circuits from R-S Components.
hellmuth , df7vx
DL2MAN
 

Posts: 706
Joined: 30 Dec 2021, 19:18
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Re: TCA9555pwr ports defect

Post by DL2MAN »

PCA9555 and TCA9555 are available in large quantities at mouser....

On my group buy page, and here in the group buy organizer forum there are links where to get what:
https://dl2man.de/1-trusdx-group-buy/
viewtopic.php?t=71
Package needs to be TSSOP24, not SSOP !

73 Manuel, DL2MAN
storyofyouandme
 

Posts: 54
Joined: 03 Jan 2022, 15:30

Re: TCA9555pwr ports defect

Post by storyofyouandme »

I tried five pieces of TCA9555, but they didn't work. Maybe the dealer sold me a refurbished product, but I used the same batch of TCA9555 on the DL2 version of the five-band UDSX, and there were successful cases. Later, I replaced the PCA9555 I bought from other dealers. The relay works normally. So I suggest that if you want to replace the 9555, try to replace the PCA9555. Although the TCA9555 is an upgraded version of the PCA9555, from the perspective of use, I think the PCA9555 is better, based on my practice.
73.
hellmuth
 

Posts: 12
Joined: 14 Dec 2022, 13:59

Re: TCA9555pwr ports defect

Post by hellmuth »

Thanks very, very much for all the helpfull infos.

I have ordered:

RS Best.-Nr.: 483-7222 Herst. Teile-Nr.: PCA9555PW,112 Marke: NXP
NXP E/A-Erweiterung, 16-Kanal I2C, SM Bus, TSSOP 24-Pin 400kHz SMD

this Cicuits from RS Components.

What i have heard from Mouser ... Manuel, before I call RS Components
I did a phone call to Mouser.
And there I have heard:
I must pay a special price for small quantities ( very high)
next a high price for Fedex Deliverie
and last but not least something Tax
because the Mouser Gentleman told me , that these circuits are delivered from U.S.
So ... a single Device costs approx. 25,00 or more Euros.

Manuel Thanks for your LINK about Mouser. I will try that if it will be nessesary.
73s hellmuth , df7vx
DL2MAN
 

Posts: 706
Joined: 30 Dec 2021, 19:18
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Re: TCA9555pwr ports defect

Post by DL2MAN »

Once, you exeed 50$, shipping is free. You pay sales Tax in advance, and when I ordered the same day
Reichelt (Germany to Germany) and
Mouser (USA to Germany) -> Mouser won the last 3 times in terms of speed.

Mouser is sometimes a little bit more expensive, but they have almost everything.
For Example: BS170s/wide selection of NP0 Capacitors/Si5351/TCA9555/etc....
If you order at mouser: Order more and stock up.
Then they beat everyone else. At least, that´s what I do.....

My last order was just a few toroids to test. Then I added another 100x BS170´s and I was over the free shipping amount....

73 Manuel; DL2MAN
hellmuth
 

Posts: 12
Joined: 14 Dec 2022, 13:59

Re: TCA9555pwr ports defect now SOLVED

Post by hellmuth »

Good morning to all .
Here the good News: Operation sucsessful
Yesterday Afternoon ( only 22 Hours for delivery) I got the PCA9555 TSSOP parts from RS Components .

Today morning I removed the defect Device from RF Board, cleaning the solderpads, apply some SMD Solder Paste
and soldering the new Device with a very small 12 Volt soldering pencil to the RF Board.
After once agin some cleaning and carefully inspection with a magnifying glass, I startet the nice (tr) uSDX ....and all the Relais at the RF Board now still working .
hellmuth , df7vx
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