Thinkpads Forum

For those electrical engineers out there, please bear with me ...I'm better with software and networking

I have a T60 (2613) that I've used on and off over the last few yrs. A few weeks ago I was moving it while it was connected to the power cord, heard a crackle, and realized the plug that goes into the DC in receptor was sparking and wires were exposed. (I read that was a common issue with the standard adapter package.)

I was going to order the replacement part (AC adapter 90W 20V - FRU 42T5000) online but decided I didn't want to wait, so I went to the local office store to find a replacement.

I asked the floor sales guy if he had what I needed. I was presented with a Targus 90W 19.5V charger. The amps on the original part is 4.5A. The replacement he handed me was 4.61A. I asked if the difference in voltage and amps would cause an issue and I was assured since the 90W output was the same, the part would do the trick. I had my doubts but thought I'd give it a whirl.

I plugged it into the laptop at home and the battery began to rapidly discharge and then gave me the battery error message and shut down. (The plug icon never popped up to recognize the adapter BTW.) I was going to need a new battery soon just based on the age/use of the old one, so I opted to purchase a new one online.

While waiting for the battery, I did attempt to see if the machine would run with plugged in with no battery. Not surprisingly it would not start up.

I thought perhaps between the frying of the first adapter and the off voltage/amps of the 2nd adapter that I fried the DC in, so I ordered that replacement kit.

Got the new battery and when in the machine it was discharging at around 1% per minute.

So I dissassembled the machine and installed the new DC in part and reapplied grease to the CPU etc.

Got it all back together and it still runs fine however the battery continued to discharge and of course the adapter won't charge it or power the machine.

So after reading other advice on here, I'm guessing I either fried the charging circuit or the motherboard (FRU 41W1454). (Unless the incorrect adapter could be doing all of that.)

So my questions are:

1) Will the difference of .5V and .11A cause a lack of charging and/or damage the circuitry?

2) Is there anything I can use in PC Doctor or the Power Management Settings that will allow me to pinpoint the source of the problems (ie: fried charging circuit vs other damaged component).

3) If I can't use a software/management setting to determine the problem, is there a good way to tell which component is the source of the prob? If I were to take the mobo to a big pc parts store, could they do a quick test and pinpoint if it was the board or the circuit?

I don't want to purchase a new mobo if it's just something as simple as the adapter, but considering the rate of discharge on the battery when the adapter isn't connected, I'm thinking something is awry inside.

Feel free to add some obligatory laughter at all I've done thus far to potentially exacerbate the problem. I just have to laugh

Thanks in advance for any advice you can offer.

Should be clear to you now, that the Targus adapter has royally screwed your laptop.
The voltage/amperage difference is no problem, they are close enough, but the plug-wiring is most likely different from an original IBM/Lenovo power supply, and caused the premature demise.
Buy/borrow a proper adapter and see how it goes, but I'd say that you need a new mobo.

Welcome to thinkpads.com!

The sales guy didn't give you entirely accurate advice when it comes to "90W". Just because the Targus power supply is rated the same wattage as the original Lenovo/IBM adapter does NOT guarantee it's a valid replacement. Wattage is a simple multiplication formula. 19.5 (volts) X 4.61 (amps) = 89.895, or rounded up, 90 watts. The original DC adapter is 20V at 4.5A, or 20 X 4.5 = 90. By his logic, a 90W adapter that outputs 10 volts at 9 amps would work too, but that voltage is not enough to power the laptop. Yes, 19.5V is close enough to 20V (only a 3% difference) so the Targus adapter is probably okay in that respect. MORE important is the polarity of the DC plug. Besides having to supply the T60 with the correct DC voltage, the polarity of the DC plug must be the same as the original. Look on the Targus adapter or the documentation that came with it. There should be a diagram similar to the one in the lower right of this picture:



This says that the inside of the barrel (the metal wall) is the POSITIVE connection and the metal jacket surrounding the outside of the plug is NEGATIVE. If you bought a "universal" adapter, most likely you had to select the proper tip style for the DC plug and connect it to the end of the adapter. You should double check that the polarity is correct but of course if it's wrong, it's probably too late for your motherboard.

As far as trying to troubleshoot the problem, you can try the following:

- ask RBS suggests, obtain a proper adapter that is known to work
- if that's not possible, get a multimeter (aka, voltmeter) and measure the voltage at the adapter's DC plug to see if it's still near 20V and the outside if the barrel is the negative connection
- PC Doctor does not have any tools to determine the voltage problem. If your verify that the adapter is supplying the correct voltage and polarity end the end of the DC plug and the T60 is not able to turn on without the battery, then there's some basic power issue with the motherboard.
- Taking the motherboard to a repair shop will probably not be too useful. I would imagine that most laptop repair shops would take the same route of replacing the entire motherboard that's been suggested here. It's not too cost effective to spend several hours trying to find all of the parts that have blown up, unsoldering them, putting the new parts in and verifying everything is working right. Much easier and less expensive to simply swap out the board with a known good unit.

First of all buy a used or new ORIGINAL AC adapter, and then make experiments

Thanks to all for the input.

I really think it was the Targus adapter.

To rkawakami, thanks for the clarification on the polarity. I thought that's what it was based on the pic on the original adapter. There was no image of it however, on the Targus adapter. I thought surely if it said it was compatible with IBM, that would be the same. My mistake.

Oddly enough I can't seem to find polarity listed anywhere on the adapter itself, on the Targus box, on the literature, or even on their own site. In doing some research it appears they tend to be tighter lipped with consumers (based on comments I've seen) when it comes to full disclosure in that arena. (Why that is, I'm not entirely sure, because the box itself says Targus isn't responsible for damages that result from use of their equipment.)

I'm going to buy the adapter off the Lenovo site (I see they've made some modifications so the plug into the DC isn't supposed to wear and fray as easily as before). That way I can have the proper one and try it. If it works, great, if it doesn't, I'll buy a new mobo and go from there. I don't want to risk buying a new board and frying it with the Targus.

The sad thing is, as I work on several different machines in a month, it took me more than 14 days to determine the problem was most likely the adapter and the office store has a 14 day return policy on electronics (30 days for misc). Blimey!

At least you've educated me on adapter protocol for future use. I'll be sticking to OEM from now on.

Thanks again for the input. I'll drop an update on here once I receive the adapter (and mobo if needed), for those who may be interested.

FBTT

If you're interested in a genuine Lenovo adapter, I have them listed in the marketplace both used and new, far cheaper then lenovo and probably far cheaper then you paid for a universal.

Although if I understand you correctly, I think it was the frayed wires that fried your system, the generic power supply may not have had anything to do with it. This is just speculation of course, but anytime you have a problem like that, unplug it asap and replace it.

ps. feel free to PM me if you would like an adapter.