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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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motherboard cpu power section check
My laptop freezes when I connect the power cord, works well on battery
only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 T5300 5648B999 SL9WE 1.73/2M/533 INTEL... copyright 06 |
#2
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motherboard cpu power section check
Mike De Petris wrote:
My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 T5300 5648B999 SL9WE 1.73/2M/533 INTEL... copyright 06 I don't know about acquiring a schematic for trouble shooting the MB, but the first thing I would do is test the power adapter with a load attached. I have repaired several that output the correct voltage but failed to regulate when loaded down. Also, some Toshiba Satellite computers were notorious for having power connector problems. I trust this computer does NOT have such a problem? |
#3
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motherboard cpu power section check
On Aug 13, 1:43*pm, Ken wrote:
Mike De Petris wrote: My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 * *T5300 5648B999 *SL9WE 1.73/2M/533 INTEL... copyright 06 * * * * I don't know about acquiring a schematic for trouble shooting the MB, but the first thing I would do is test the power adapter with a load attached. *I have repaired several that output the correct voltage but failed to regulate when loaded down. * * * * Also, some Toshiba Satellite computers were notorious for having power connector problems. *I trust this computer does NOT have such a problem? no problems on the connector tried different power supplies, even stabilized laboratory psu |
#4
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motherboard cpu power section check
On Fri, 13 Aug 2010 04:55:24 -0700, Mike De Petris wrote:
On Aug 13, 1:43Â*pm, Ken wrote: Mike De Petris wrote: My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 Â* Â*T5300 5648B999 Â*SL9WE 1.73/2M/533 INTEL... copyright 06 Â* Â* Â* Â* I don't know about acquiring a schematic for trouble Â* Â* Â* Â* shooting the MB, but the first thing I would do is test the power adapter with a load attached. Â*I have repaired several that output the correct voltage but failed to regulate when loaded down. Â* Â* Â* Â* Also, some Toshiba Satellite computers were notorious for Â* Â* Â* Â* having power connector problems. Â*I trust this computer does NOT have such a problem? no problems on the connector tried different power supplies, even stabilized laboratory psu Did you try cleaning the air ducts? When on batter the CPU 'may' be at a reduced clock speed via Toshiba Power Management when on battery. When on the PSU, the CPU will go to full speed and may just be over heating. Food for thought -- -- Live Fast, Die Young and Leave a Pretty Corpse |
#5
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motherboard cpu power section check
On Aug 13, 4:23*pm, Meat Plow wrote:
On Fri, 13 Aug 2010 04:55:24 -0700, Mike De Petris wrote: On Aug 13, 1:43*pm, Ken wrote: Mike De Petris wrote: My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 * *T5300 5648B999 *SL9WE 1.73/2M/533 INTEL... copyright 06 * * * * I don't know about acquiring a schematic for trouble * * * * shooting the MB, but the first thing I would do is test the power adapter with a load attached. *I have repaired several that output the correct voltage but failed to regulate when loaded down. * * * * Also, some Toshiba Satellite computers were notorious for * * * * having power connector problems. *I trust this computer does NOT have such a problem? no problems on the connector tried different power supplies, even stabilized laboratory psu Did you try cleaning the air ducts? When on batter the CPU 'may' be at a reduced clock speed via Toshiba Power Management when on battery. When on the PSU, the CPU will go to full speed and may just be over heating. Food for thought -- thank you, anyway please consider the laptop is completely teared a part, non problems of air flow, and when connectinh power it locks immediately even if in the BIOS pages |
#6
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motherboard cpu power section check
On Fri, 13 Aug 2010 09:25:13 -0700, Mike De Petris wrote:
On Aug 13, 4:23Â*pm, Meat Plow wrote: On Fri, 13 Aug 2010 04:55:24 -0700, Mike De Petris wrote: On Aug 13, 1:43Â*pm, Ken wrote: Mike De Petris wrote: My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 Â* Â*T5300 5648B999 Â*SL9WE 1.73/2M/533 INTEL... copyright 06 Â* Â* Â* Â* I don't know about acquiring a schematic for trouble Â* Â* Â* Â* shooting the MB, but the first thing I would do is test the power adapter with a load attached. Â*I have repaired several that output the correct voltage but failed to regulate when loaded down. Â* Â* Â* Â* Also, some Toshiba Satellite computers were notorious Â* Â* Â* Â* for having power connector problems. Â*I trust this computer does NOT have such a problem? no problems on the connector tried different power supplies, even stabilized laboratory psu Did you try cleaning the air ducts? When on batter the CPU 'may' be at a reduced clock speed via Toshiba Power Management when on battery. When on the PSU, the CPU will go to full speed and may just be over heating. Food for thought -- thank you, anyway please consider the laptop is completely teared a part, non problems of air flow, and when connectinh power it locks immediately even if in the BIOS pages Had no way of knowing since you didn't mention these additional facts in your original post. -- Live Fast, Die Young and Leave a Pretty Corpse |
#7
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motherboard cpu power section check
On Aug 13, 9:25*am, Mike De Petris wrote:
... the laptop is completely teared a part, non problems of air flow, and when connectinh power it locks immediately even if in the BIOS pages There's a second CPU (a little tiny one) that handles the power sequencing. The 'BIOS pages' are only for the big CPU, it's that little battery-monitor one that runs into some kind of trouble, and it has that problem every time the external power is applied and it tries to do the natural thing, run the computer from external power and charge the battery. Somehow it senses overvoltage or overcurrent and shuts down. Look for small-value current sense resistors that are open, or for semiconductor switches that are shorted (can't turn off). There are often PMOS power switch transistors involved. Also, look for fuses (they might not LOOK like fuses, though). Battery charge current might be channeled through a switchmode regulator, those have always had problems if a capacitor fails. |
#8
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motherboard cpu power section check
"Mike De Petris" wrote in message ... My laptop freezes when I connect the power cord, works well on battery only. I want to check the motherbard in search for the faulty component, where could I find pinouts and voltages to check for? Toshiba Satellite A205-S4577 (PSAF0U-01Q009) Laptop Motherboard: MAIN BOARD 945GM. Main Board 945GM EXC+51 CA+MIC MDC 1310A2120812 Alternate Part Numbers: V000108030 Processor: LF80537 T5300 5648B999 SL9WE 1.73/2M/533 INTEL... copyright 06 try here http://www.reepair.net/en/forumdispl...top-Schematics zack |
#9
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motherboard cpu power section check
On Fri, 13 Aug 2010 01:56:24 -0700 (PDT), Mike De Petris
wrote: My laptop freezes when I connect the power cord, works well on battery only. Toshiba Satellite A205-S4577 (PSAF0U-01Q009) http://laptopforums.toshiba.com/t5/Batteries-and-Power/Laptop-will-only-run-on-battery-freezes-when-the-ac-is-plugged/m-p/114865 (5 pages). Lots of good suggestions some of which include successful repairs. Mo http://www.fixya.com/support/t2946491-freeze_when_power_cord_plugged_in http://laptopforums.toshiba.com/t5/Batteries-and-Power/Laptop-shuts-down-as-soon-as-adapter-plugged-in/td-p/114041 I've seen this twice and fixed it more by accident than by intent. In one case, I left the battery out of the laptop, and no charger plugged in, for about a weekend. When I returned on Monday, everything magically worked normally. In the 2nd case, I was trying various combinations of starting the computer, with the battery, without the battery, with both, etc. At one point, it magically started working. That was about 1-2 years ago, and both customers are still using the laptops. However, I have another Toshiblah laptop in the office with similar (not identical) problems, that I can't fix. It also won't charge the battery, although it will run on battery if I charge it in another laptop. The problem was traced to a crappy BGA soldering job on the video chip. Try booting from battery in Safe Mode, and then plug in the charger. If that works, then it's probable that you have a video chip soldering problem. (I'm debating the merits of buying an overpriced hot air rework station. I borrowed one, liked it, but had to return it). Please do not tinker with external power supplies unless you're absolutely sure you're using the correct power plug, and the correct voltage. I've seen what's left of the laptop when the clip leads get swapped, or the power supply mysteriously got to maximum. It's not pretty. The correct power supply is 19v 3.4A negative ground, 5.5/2.5/12mm connector. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#10
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motherboard cpu power section check
On Aug 15, 6:03*am, Jeff Liebermann wrote:
My laptop freezes when I connect the power cord, works well on battery only. Toshiba Satellite A205-S4577 (PSAF0U-01Q009) thanks to your suggestions, I did a BIG step forward, I had a try at this: "In SafeMode Goto control panel-- device manager--- goto processor---- disable one of the two processors -- reboot normally. This FIXED the problem, but 1processor is not really a great fix; more of a work around." And IT WORKS, pc is now running on external power at the moment, a thing that I've never seen on it. I tryed disabling a cpu core in BIOS in the past unsuccesfully, but disableng from devmgmt.msc fixed it. I do not think it can be a ripple problem because it did not boot at all when connected on power, but who know? Still have to understand if it is: - faulty cpu - faulty cpu power section - bad cpu/other microcode I would try to see with scope and multimeter but still don't know exactly what and where to look for. |
#11
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motherboard cpu power section check
On Sun, 15 Aug 2010 02:12:28 -0700, Mike De Petris wrote:
On Aug 15, 6:03Â*am, Jeff Liebermann wrote: My laptop freezes when I connect the power cord, works well on battery only. Toshiba Satellite A205-S4577 (PSAF0U-01Q009) thanks to your suggestions, I did a BIG step forward, I had a try at this: "In SafeMode Goto control panel-- device manager--- goto processor---- disable one of the two processors -- reboot normally. This FIXED the problem, but 1processor is not really a great fix; more of a work around." And IT WORKS, pc is now running on external power at the moment, a thing that I've never seen on it. I tryed disabling a cpu core in BIOS in the past unsuccesfully, but disableng from devmgmt.msc fixed it. I do not think it can be a ripple problem because it did not boot at all when connected on power, but who know? Still have to understand if it is: - faulty cpu - faulty cpu power section - bad cpu/other microcode I would try to see with scope and multimeter but still don't know exactly what and where to look for. Is that a dual core CPU or hyperthreaded single core. -- Live Fast, Die Young and Leave a Pretty Corpse |
#12
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motherboard cpu power section check
On Sun, 15 Aug 2010 15:13:09 +0000 (UTC), Meat Plow
wrote: Is that a dual core CPU or hyperthreaded single core. 1.73GHz Intel Core 2 Duo Mobile T5300 -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#13
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motherboard cpu power section check
On Sun, 15 Aug 2010 09:25:04 -0700, Jeff Liebermann wrote:
On Sun, 15 Aug 2010 15:13:09 +0000 (UTC), Meat Plow wrote: Is that a dual core CPU or hyperthreaded single core. 1.73GHz Intel Core 2 Duo Mobile T5300 Ok it's got two cores. Reason I asked was disabling say a 2 ghz single core HT CPU can acutally boost performance. When in HT mode the RAM and the CPU process at 1 ghz. -- Live Fast, Die Young and Leave a Pretty Corpse |
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