Hi all

I have an Acer P215 laptop that will not take a charge. A faulty power supply caused the small white component to blow.

I'm not sure where this component is a fuse or zero ohm resistor. I know I can bridge the connection to get it to work but I would like to replace the part as the manufacturer intended.

I have since desoldered the part to inspect underneath but there are no markings on it at all.

If it is a fuse, at what rating? The power supply is 19v 3.42a.any help would be much appreciated

 

Welcome to AAC.

That is definitely a Polyswitch, which is a resettable fuse. Given the location next to the USB charge controller chip, and its physical size, it is probably something like 750mA, at a guess.

You might have to replace it it with something that looks different since that package suggests the manufacturer bought a large quantity and a direct replacement will be impossible.

 

Hi Ya'akov

Many thanks for the reply.

Would it really be so low at around 750ma. The reason I say this is because it is directly in line with the power connector and there is continuity between them.

I was thinking the polyswitch was more for the main DC line in. As it is diagnosed to be a type of fuse, if I'm right, what amperage would be suggested, 3a?

 

Hi Ya'akov

Many thanks for the reply.

Would it really be so low at around 750ma. The reason I say this is because it is directly in line with the power connector and there is continuity between them.

I was thinking the polyswitch was more for the main DC line in. As it is diagnosed to be a type of fuse, if I'm right, what amperage would be suggested, 3a?

The size suggests.a 0.75A hold 1.5A trip device.

 

Many thanks!

 

For the P215 I find a power supply rating of 65 W. Assuming it's using PD resp. alike, that would be 20 V @ >3 A. So the current rating should be >= 3 A.
BTW: polyfuses (polyswitches) usually fail short, not open. It's just a matter of how often it activates. (Usual specs range from 10 to maybe 100 activations until failing short.)

If this one failed open it's most likely a classical fuse, not a poly* one. Measure the body size (LxW) and use the parametric search e.g. @ digikey.com to find a replacement. I'd go for something like 3.5 A / 24 V DC in the case required.

 

For the P215 I find a power supply rating of 65 W. Assuming it's using PD resp. alike, that would be 20 V @ >3 A. So the current rating should be >= 3 A.
BTW: polyfuses (polyswitches) usually fail short, not open. It's just a matter of how often it activates. (Usual specs range from 10 to maybe 100 activations until failing short.)

If this one failed open it's most likely a classical fuse, not a poly* one. Measure the body size (LxW) and use the parametric search e.g. @ digikey.com to find a replacement. I'd go for something like 3.5 A / 24 V DC in the case required.

While your logic is sound, it's hard to find a fuse that fits those parameters, in that package size and type.

The Polyswitches _do_ come in packages like the one shown and tend to be the 750mA variety.

So, there are two possible paths here. Fortunately, the part is cheap and the Polyswitch doesn't work a slow blow fuse can be tried.

 

While your logic is sound, it's hard to find a fuse that fits those parameters, in that package size and type.

The Polyswitches _do_ come in packages like the one shown and tend to be the 750mA variety.

So, there are two possible paths here. Fortunately, the part is cheap and the Polyswitch doesn't work a slow blow fuse can be tried.

I can hardly assess the size of the fuse, but checking with digikey's parametric search found such fuses starting as small as 0603 !