PSU for ThinkPad W520

B

balanga

The PSU for my ThinkPad W520 suddenly stopped working yesterday and am wondering what to do about it. Are they repairable or do I need to find a replacement?

It's a really big heavy PSU, a genuine Lenovo 170W 20V. Every other PSU I have is about half the size of this one. So as long as my replacement has this power rating should it suffice?

Whilst looking for alternatives I came across various GAN chargers and wondered if one of these could be used as a replacement. Anyone know?
 
After some searching I'm told that I need something which has 'Lenovo barrel plug + ID pin handshake'.

What on earth is ID pin handshake?
 
balanga said:
So as long as my replacement has this power rating should it suffice?
Click to expand...
If the voltage fits exactly, rated power or current is >=, and the plug matches, which could be replaced with the one of the defective PSU (watch out to have correct polarity!), then yes. Except:
balanga said:
What on earth is ID pin handshake?
Click to expand...
I guess it's something to avoid you're using anything but original Lenovo hardware, which does exactly same at the same quality than any third party product, but cost at least as twice as much. 😁
 
 
balanga said:
After some searching I'm told that I need something which has 'Lenovo barrel plug + ID pin handshake'.

What on earth is ID pin handshake?
Click to expand...
The ID pin handshake is a protocol that occurs on the central pin that you can see inside the plug. Power is delivered by the sleeve itself, if you look closely you will see that it has both an inner and outer conducting surface. The central pin is used for a signalling protocol to check that it's hooked up to a valid PSU. The W520 needs a decent amount of juice, so my advice is to get the genuine article.
 
If you want to try repairing it... remember these things are mostly SMD construction, so various degrees of difficulty repairing them, depending on what happens to be wrong. Personally I wouldn't bother, just get another one.

View: https://www.youtube.com/watch?v=RNVfHx8wAGY

View: https://www.youtube.com/watch?v=Wq1VE_TAxWc

If yours is potted like this 170W one, then you've got the additional fun of removing the potting compound. He basically wrecks it when he takes it apart anyway, you're not going to get it back together again after what he shows in this video.
View: https://www.youtube.com/watch?v=ibYUi3TA5Us

View: https://www.youtube.com/watch?v=-hc4kNAc5VU
 
balanga said:
The PSU for my ThinkPad W520 suddenly stopped working yesterday and am wondering what to do about it. Are they repairable or do I need to find a replacement?
Click to expand...

I bought a replacement shortly after this post and it only lasted six weeks/

I ordered a new one but I'm surprised that two of these PSUs have gone bad. This is the first laptop PSU I have in 20 years that have failed.

Now that I have bad ones I may try fixing one.
 
balanga said:
After some searching I'm told that I need something which has 'Lenovo barrel plug + ID pin handshake'.

What on earth is ID pin handshake?
Click to expand...

I have a W520 as well as X220 and T420 from the same generation -- and some older Thinkpads. They all use the same PSU design, but the W520 is slightly different: it has two small flanges inside the barrel, so it will only connect in one orientation. This means that it cannot be plugged into any lower-end model with a lower power draw.

The W520 will run but not charge from a 90W PSU.

I fear you will need the exact model. :-(
 
lproven said:
I have a W520 as well as X220 and T420 from the same generation -- and some older Thinkpads. They all use the same PSU design, but the W520 is slightly different: it has two small flanges inside the barrel, so it will only connect in one orientation. This means that it cannot be plugged into any lower-end model with a lower power draw.

The W520 will run but not charge from a 90W PSU.

I fear you will need the exact model. :-(
Click to expand...
Thanks for the suggestion. I tried usng a 90W but my W520 would not start up, however, I just noticed that the charging light is flashing so I'll leave it for a couple of hours and see if it gets charged up.
 
It looks like I can start up my W520 if I leave on charge for some time so I can use it temporarily although I don't know for how long.

I assume that the charging light will turn green when fully charged. If it does I'll see how long it will run for. In future, I will shhutdown at night and just leave it on charge.
 
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