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Electronics => Repair => Topic started by: MrZwing on August 15, 2015, 05:03:59 pm

Title: Really old laptop problem (possibly the power supply)
Post by: MrZwing on August 15, 2015, 05:03:59 pm
Hello
i have a CAF PROlite 286/16 laptop one of those really old "portable" computers that still require you to plug in a cable to the mains since it has no battery but a power supply built into it.

Now when i have pulled every plug from the motherboard and other items and the power-supply starts without any problem.
and when i hook in a floppy drive it shows no problems.

now the motherboard has 2 sockets for power and its the same kind of power-cable as the floppy disk has and as soon i hook up either of the power inputs the power-supply just doesn't start but instead just lets out a ticking sound almost like a relay or like a tiny discharge.

so the question is is the motherboard broken or is it something wrong with the power-supply. since i  cant see anything on the motherboard that indicates something broken.

MrZ
Title: Re: Really old laptop problem (possibly the power supply)
Post by: Ketturi on August 16, 2015, 12:06:25 am
Ticking sound from a power supply can indicate short circuit, supply tries to start but as soon as voltages raises, a protection kicks in and shuts off it again in constant loop (well this is what happens with a Toshiba T5100 "laptop"). Start to check with multimeter if any of the power pins have shorts to each other or ground. If not, then it could be the supply not handling full load due old n' dry electrolytics.
Title: Re: Really old laptop problem (possibly the power supply)
Post by: MrZwing on August 16, 2015, 02:05:33 pm
Hmm i will do some testing and see if i can find some kind of error.

could possibly be the caps as you mentioned.