K4700 problem


I have 2 K4700 kits. First one work correct but second is little weird.
Wait LED stays almost whole time ON even after relay click. It dims maybe 20% but on first one kit it dims by 90% what I found its normal. (I already read here about it, that new leds need less power. I got it.)
My question is, why on second kit wait LED stays on even after relay click? I measured voltage on LED and I realised that on First one that works normal voltage is lower about 0.3V on LED. I already try to replace T1 T2 T3 T4 from kit that works and same problem. Also, I already try to change LED…just cant find where is problem. I noticed that on first one kit that works normal relay clicks almost in same time but on second one kit there is delay about 0.5sec so I hear 2 clicks, probably first click from first relay then after 0.5 sec from other relay. Weird.
I checked all soldering joints, diodes polarity and resistors about 5 times and im really confused.

Can you please guide me where and what to check and measure? What problem could be if both relay doesnt click in same time?

It is possible that you may have a component in the wrong place or wrong polarity or soldering error.
You may want to post some clear pictures on a website and put the link up here so it can be checked.


Links on pictures:
Back side link (I turn desk light on so joints are shown better.)
This muddy thing is paste from resoldering and replacing parts. Joints are clear as you see.
Front side link

I checked it 5 times for shure and still cant find error. Maybe somebody of you here see something that I cant see right now…THANKS!

I can’t see anything wrong.

Is it possible you got T3 and T4 swapped?

No I just checked again. T1,T2,T3 = 547B, T4 = 517.
I can zoom and picture it too…

I also measured on this kit that doesnt work right between V+ and V-. Its 13.9V
ON kit that work its 14.4V.

Before relay click on wait led i got 2.14V and after relay click, it was 1.97V and its for about 0.3V more if I compare it with kit that works perfect.
Does it mean something?

Anything else to try? :frowning:

This is huge guess on my part.
Maybe T3 has an issue.

Mistery solved. I dont know why T3 was issue and how it came bad. Just replaced T3 from kit that works to “faulty kit” Faulty kit starts working like charm. So it was T3.
Nice diagnose man. You saved me from headache.
Many thanks!

Wow! Got lucky again.
Enjoy your kit.