My Sony laptop works fine as long as I have the battery inserted while using AC power
I have a Sony Vaio PCG-FRV37. I bought it used and it works fine as long as I have the battery inserted while using AC power. The battery is a few years old and could stand to be replaced, however, I don’t want to get a new one until I correct the AC problems I’m having. If I try to start up the unit with AC power alone, it starts to boot up and the monitor comes on. But then it immediately shuts off. From there I can’t even perform this “false start” sequence unless I unplug the AC adapter from the unit and plug it in again. Press power and then…same thing. Sometimes it will stay on long enough to give me the “Windows Safe Mode” screen, but before you’ve had enough time to read it, it shuts off. If I leave the battery in the unit, I can start it up. When I get through the user log in and actually get to my desktop page, I notice a lot of activity from the “Power Meter” power monitoring icon. When you bring the power meter page up, you will see the power status keeps jumping back and forth randomly between modes of charging. Current Power Source AC power, then Batteries, then AC , then Batteries again. Sometimes it’s slow between changes and sometimes it changes a couple of times a second. If you pull the battery out of the unit, it of course shuts off because for that instant it jumps from AC power to Battery power, it sees no battery and out it goes. I’ve checked the voltage on the AC adapter and it reads 19.5V as it should. I’ve also tried removing various items from the computer in systematic fashion (keyboard, static guard? various screws to see if continuity was an issue, etc.) but to no avail. It’s a nice computer and I got it real cheap so I’d like to fix it as long as it doesn’t past that point to where it makes more sense to buy a new one. I’d appreciate any help anyone could give me.Thanks.
I think you might have a problem with the power jack. It’s either a broken power jack or a loose connection between the power jack and the motherboard. If you want to fix the laptop, you’ll have to take it apart and take a closer look at the power jack. Replace the power jack if it’s broken or resolder the jack.
February 13th, 2007 at 12:07 am
Your website is great for us techno people.
I came across a similar problem. The two pins of the power plug to my FOSA 290 I2 laptop shorted and burned out. Luckily the powerpack was not burned out. Since I could not find a similar plug, I replaced it with a pair of BNC plug and socket. I desoldered the socket from the motherboard. I found three holes originally occupied by the socket. They were just next to a component labelled as D102 8221. I connect the middle hole with a red cable to the positive terminal of the plug, and joined the hole on the right with a black cable and the hole on the left with a white cable, and joined both cables together to the negative of the plug. When I started the computer, it could not load Windows properly. When I took the battery out, it worked alright. The computer charged the battery, but using the battery could not run Windows. I suspect that I should not connect the white cable to the black cable.
I would like to know whether there is a mechanism in the socket which connect these three wires, just like the ordinary power socket. When the battery is connected, the third wire may be used to sense the degree of charge so that the computer stops charging when the battery is full. When AC is not on, the computer will be powered from the battery.
I would be most grateful if anyone of you could advise me. Thank you very much.
February 13th, 2007 at 11:53 pm
Hey Kin,
What do you mean by “When I started the computer, it could not load Windows properly.”? The laptop will not start from the AC at all or something else is happening?
I cannot give you an advice on how to connect the wires because all laptops are different.
February 14th, 2007 at 11:18 pm
Dear Laptop Freak,
Thank you very much for your reply. I am very glad to receive your query.
My FOSA 290 I2 is a very old laptop but it worked well and provides me with the printer port, comm port and a USB port so that I can use it to program my microcontrollers. The battery pack was old and not quite working, so I usually took it out of the computer and ran the computer directly from AC using the adaptor. Since there is a company replacing aging batteries inside the battery packs, I sent my battery pack to get the batteries replaced. One day before I got the battery pack, when I was working with the computer, I noticed a burning smell and found the plug of the adaptor melted. As the computer is old and not common, I could not locate a similar plug to match the socket on the motherboard, so I had to try something else. It was easy to change the plug into a BNC plug, but when I desoldered the socket, I got three terminals. I got the positive identified, so I soldered it with a red wire. I identified the negative and soldered it with a black wire. I soldered a white wire to the third hole. I thought the socket would work like an ordinary socket of a charger which has three terminals. One terminal connects to the positive and one connects to the negative while the third should touch one terminal when the plug is not inserted, and break when the plug is inserted. So I connected the white wire and the black wire together to the negative of the plug. When I am using the AC adaptor alone, I can start my Windows 98 SE perfectly. But when I inserted the battery, I can only get the Windows loading for a while and then it hangs somewhere. But when I take the battery pack out, it works fine again. Someone told me that it was due to the power mangement subroutine of the Windows OS and advised me to reinstall Windows. When I have the battery pack inserted, I could not install Windows unless I took it out. So I suspect that it must be the connection of these three wires.
I understand the there are so many laptops with so many different designs, it is diifcult to get advice. That is why I am overjoyed by your reply. I have tried very hard to find a schematic of the computer to find out how the three terminals are connected but in vain. I think all charging sockets, no matter how different the designs are, should have the same principle of connection. If anyone who have access to service manuals with schematics, I would appreicate very much if you could check the connection of the three wires on how they are connected at the socket. I think that may solve my problems.
Thank you very much again for your interest and help.
February 15th, 2007 at 8:24 pm
I think it’s possible that you have some kind of software problem.
Here’s what I would try. Do you have a CD-Rom in your laptop? If yes, you can try booting the laptop from a live Linux CD. I usually use Knoppix and you can get it here. This OS is very user-friendly and will boot the laptop into a Windows-like environment, it runs directly from the CD disc bypassing the hard drive so you don’t have to reinstall Windows 98. Download .iso file and burn in on a CD. After that try booting the laptop from this CD just on the battery power and with AC power too. If the laptop works fine both ways, probably there is nothing wrong with the power connector and your problem is software related.
February 21st, 2007 at 8:47 pm
Dear Laptop Freak,
Thanks a lot for your advice. I made the CD and tried running the laptop from it. It worked well when I took the battery off but could not boot properly when I inserted the battery. So I took the black and white wires from the socket and separated them. I removed the battery and tried booting the laptop by connecting first the black wire. It worked. Then I tried booting the laptop with the white wire. It also worked. I then checked the resistance between the white and the black wire. It was zero ohm, so no harm done when connecting the two wires to the negative of the BNC socket.
I then tried to boot using the battery alone. The laptop stopped loading somewhere in the booting process. The laptop sounded single beep continuously every second. So I think it was the battery that caused the problem.
I checked the resistances between the fingers inside the battery compartment of the laptop without connecting the power adaptor. The fingers are arranged as follows:
__________________________________
| || | | | | | | |
1 P 2 3 4 5 6 7 8
P denotes the plastic peg which separates pins 1 and 2.
I found that pins 1 and 2 were connected together and pins 7 and 8 were connected together, so there was no resistance between 1 and 2 and 7 and 8 respectively. 3 and 4 were not connected so the resistance was infinity. 1 and 2 was connected to 3 through a diode. 3 was connected to 5 through a diode and 5 was also connected to 4 through a diode. 1, 2 and 7, 8 and 5 are connected through some resistors, diodes and capacitors.
When the adaptor was switched on, there was no potential difference between pins 1 and 2 and pins 7 and 8 respectively. The PD across 1, 2 and 5 was 3.41 V and that across 1,2 and 7, 8 was 94.5 mV.
I checked the battery carefully. Pins 1 and 2 were positive while pins 7 and 8 were negative. The PD was 11.20 V. The PD across pins 1, 2 and 3, 4 was 9.34 V and that across 1, 2 and 5, 6, 7 and 8 was 11.20 V. 5, 6, 7 and 8 were found to have the same PD. I also measured the resistance between some of the pins and found that pins 6, 7, 8 showed zero resistance. The resistance between pins 3 and 4 was 330 Ohm; that of pins 4 and 5 was also 330 Ohm while that of pins 5 and 6 was 100 Ohm.
My problem now boils down to the battery pack. Since it was serviced by replacing the batteries, would it be possible that some of the connections were mistakenly connected? If I can get a schematic of the battery pack, the problem may perhaps be resolved.
I would thank Laptop Freak for your kind assistance in time and effort. I would like people who have serviced battery packs to give me some advice.
Thank you very much and I look forward to the advice.
April 2nd, 2007 at 3:46 pm
There is no way that wires were crossed during th battery replacement. I just finished replacing the battery cells in my battery and I have pics if needed.