I have added the capacitors to one of my units similar to that shown in the picture from previous respondent with success.
Cheers
Hello, i have a revA 20230512 version.
Compare to the previous versions, there is new R54 composant right next a T343B oscillator.
Can I install the 8pf capacitors in the same way as shown previously by Medicina2004 ?
Thanks
I would do this as I have done previously with success.
It will test you skills with a soldering iron.
Cheers
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A big thank you to everyone!
I managed to complete the repair recommended by Medicina2004. Sorry Okjames, my soldering skills aren’t up to scratch yet 
Salve a Tutti,
allora anche io ho avuto lo stesso problema con la IIC-800, la mia scheda è una Rev.A del 20230512 e monta un clock HT1381A del 2012 con quarzo T343B (tale quarzo non si trova documentazione)
Dal datasheet del HT1381A è chiaro che tale chip non necessita di condensatori aggiuntivi, ma segnala che tale componente è soggetto a disturbi sulla rete elettrica, per cui consigliano la realizzazione di un filtro con R1 e C1 messo sul pin VSS del HT1381A
La cosa mi conferma, che la IIC-800 a casa a Roma funziona perfettamente, ma installata alla casa al mare dopo qualche giorno va in errore, ed anche se la spengo e attendo che si scarica e poi la riaccendo va in errore con il solito bip dopo 2 minuti
A questo punto proverò a installare un filtro per rete elettrica a 220vac prima del trasformatore 220vac-24vac, in modo da non avere disturbi sulla rete elettrica
Vi farò sapere se risolvo
You would need to check if if the chip version is 1381 or 1381A. If they have fitted the A version then R1 should have been mounted on the PCB and the correct crystal (9pf loading) fitted. I don’t think that’s the case, I did not see a 10M resistor around the circuit, but I can’t really remember. Fitting the loading capacitors as many of us have done has fixed the problem.
The mains filter is unlikely to do much as the power supply is a transformer and not switch mode so most interference would be lost in the transformer core. Adding C1 close to the HT1381A would be most effective. However it would be interesting the know the outcome, I would think it the problem would be less frequent at best.
However looking at this image from another user the R1 resistor and C1 capacitor may well have been fitted with the HT1381A chip. If that’s the case and this issue still happens then Holtek have a design problem with their chip where the two loading capacitors are still needed.
Reviving this thread. I got capacitors and solder them on as in the pictures but still get line error after about a minute of power up.
Any other recommendations?
The crystal oscillator in the HT1381 is very sensitive where the crystal and loading capacitors need to be small and fitted as close as possible without long wires. You could try to shorten the capacitor legs or even replace the crystal (32.768Khz). Best solution is using surface mount capacitors (SMD) 0603 size as shown in the previous posts.
Всем привет! На моём устройстве IIC-800 wifi появилась ошибка “Time error”. Прочитав данную ветку было принято решение заменить кварцевый резонатор. Был куплен 32768 в корпусе SMD, по размерам такой же, как установлен на плате. Замена этого элемента дала результат: ошибка не появляется, устройство работает штатно. Установка дополнительных конденсаторов не потребовалась. Мой вариант на фото. Элемент “Y1”
Hi all.
I got the same issue 5 weeks ago.
The timer was wired and positioned in the equipment room at basement level where humidity is higher.
Moving it to a room within the apartment, the issue disappeared after 1 hour. It also reappeared moving the device back to the original site.
Ever since also other users mentioned some humidity influence, I tried placing a very small silica gel bag next to the crystal (picture attached). This solved the issue and the timer has been working perfectly since that day (more than 1 month today).
Once the absorption capability of the small bag will be exhausted, the issue could also reappear. We will see.
I think that the solutions applied by the other users with a different clock source and/or additional capacitors is a longer term one or the final one to achieve stability of the clock source.
Just to share the quick-and-dirty approach if you are in a hurry or waiting for the components bought online…
Mario
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