Well since my clock don't work, I pulled it apart and it sat on my desk for a few days, eventually I began search tech section and i found that I could fix it by replacing two 180 ohm resistors. Awesome. I measured the resistance on the old ones and both of them displayed 90 ohms, Im assuming they must be worn out since they should be reading 180 ohms. So off I go looking through my jars full of resistors, i could only find a 100 ohm. ( I have a hobbyist electronics kit, lol ) Damn im thinking, but then... I had an epiphany, haha if the worn out resistors are reading 90ohm and I have a 100 ohm, then that equals 190ohms total. Should work yeah? So just for laughs I went out to the car turned the key on, plugged the clock in and sure enough didn't work, so then I got my 100ohm resistor and decided to, without soldering it, I just touched the solder with the tips of the resistor where its ment to be and the clock lit up, and stayed lit up even when i took the resistor away. Now its been working since then. And i am confused as f***. Since its working now, I don't see why i should go butcher out the old resistors and solder new ones in. Ive come to the conclusion that my resistor must be magic, lol First person to tell me why it worked like the way I described wins a ten centimetre piece of electrical tape. LOL :rofl: Nah seriously Im stumped though. Does anyone know?
Oh man, can I please borrow your magic resistor? My clock hasn't worked in ages. It could use a little magic!
My clock works because I rebuilt the whole car :zlove: Although a resistor is a cheaper way to go :rofl:
The clock is on drugs like the rest of ours - lol! So does the resistance still equal 90ohms or has it changed??
Bit late but yes, it did still equal 90ohms, weird eh? I don't think it could of been a cracked solder joint it looked pretty good.
The vacuum fluorescent display in the Zed clock needs a high voltage to operate ? higher than battery voltage. From memory, the two 180 ohm resistors in parallel supply the current for this circuit. By the way, two 180 ohm resistors in parallel will give you a total of 90 ohms resistance, which is what you would have measured across each resistor if you tested the resistors while they were still on the circuit board. The formula for working out resistors in parallel is 1/R total = 1/R1 + 1/R2. By adding your third 100 ohm resistor in parallel to the other two, you would have temporarily dropped the total resistance to around 47 ohms. This has allowed more current to flow through the circuit, and has probably kick started the high voltage circuit back into life, or heated up a bad soldered joint so that it makes good contact again, as bazilzed has suggested. I wouldn?t recommend it as a fix though ? dropping resistance in a circuit results in more current flow, which can burn out components. A golden rule for Zeds and any old car is that if anything electrical is taken apart, closely inspect for any dirty looking or cracked solder joints, or run over them all with a soldering iron and good new solder anyway. I?ve just fixed a power window amplifier (common culprit for power windows not working) and also the heater blower motor drive circuit (a bit more rare) both of which had bad soldered joints. The speedo is also not working, and I?m betting it?s another failed soldered joint. Hope your magic fix works permanently
Thanks what you said makes perfect sense, i did only touch the resistor to the solder joint then took it off so the resistance would of dropped for a split second and the clock made a kind of tick noise and came back on. Will it still burn components like that? Oh and by the way, its kind of flickers and goes dim and bright sometimes on its own now, it hasn't died yet though. Im expecting it too.
Dangerous is right on the money. Almost certainly a dry solder joint. Looks are deceiving and the only way for sure to know is to get the trusty soldering iron out and re-do the joints. You might have disturbed the joint even with a light touch to make a connection again. Ill bet the behaviour of the clock now is mirroring what happened in the past. E
You are right, it makes sense, I think i will resolder them since it was beginning to show signs of dying again today.
I think when you leave the car in the garage for a while with the ignition off and the battery volts drop down to about 11.5 volts the problem may return when restart the car.I purchaced some half watt resisters from Dick Smiths and replaced the two faulty resisters clock fixed OK ****
Well just as an update, I have been meaning to pull it back apart and resolder the joints just for peace of mind, never had the chance yet, but,......... I have been driving around for months now and the clock is still working like a champ. :br:
So let me get this straight, you got a 100 ohm resistor and "piggy backed" it on the old resistor whilst plugged in as a test without soldering in, it worked, you removed the 100 ohm resistor and it still works???
