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| Thread ID: 75976 | 2007-01-16 19:19:00 | Paging all Hardware Gurus | B.M. (505) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 516482 | 2007-01-16 19:19:00 | Guys, I’ve been given a HP Pavilion a340a with a most peculiar fault . The position is this . When I turn it on the power supply fan comes on, the power light illuminates and the light on the DVD-CD ROM lights permanently . That’s it . There is no Bios POST Beep Codes & no video . Nor does the CPU fan or Chassis Fan come on . The power supply is providing 12v & 5v to the appropriate pins on a spare plug & I have checked, removed and tested the CMOS battery which is 2 . 99v so I recon that’s not the problem . Also I have given the Motherboard a close inspection and there is no sign of physical damage or swollen capacitors . Anything I’ve missed guy’s? Oh, as I typed this I had an idea and removed the only PCI Device (a dial-up modem) removed the RAM unplugged the keyboard and mouse and turned it on . Exactly the same! The no beep codes worries me unless the little speaker which is part of the Motherboard is faulty? I figure it should have gone crook about no RAM or Keyboard . :badpc: |
B.M. (505) | ||
| 516483 | 2007-01-16 19:23:00 | Dad's computer does a similar thing every now and then - we just restart it (with the reset button) and it works perfectly. | pcuser42 (130) | ||
| 516484 | 2007-01-16 19:27:00 | On start-up, the Power Supply Unit must give a "Power_OK" signal within about 700 milliseconds or the CPU will not reset and even begin the boot process. So I would not discount a PSU problem. |
godfather (25) | ||
| 516485 | 2007-01-16 19:48:00 | Thanks GF. The Power Supply's not hard to change so I'll start there and get back on that one. :thumbs: |
B.M. (505) | ||
| 516486 | 2007-01-16 20:29:00 | most obvious thing is to unplug the cd drive. sometimes a faulty drive can stop it booting. | tweak'e (69) | ||
| 516487 | 2007-01-16 21:20:00 | Update: Changed PSU and fault Remained. Disconnected power to DVD/CD Rom, fault remained. Virtually has to be Motherboard, CPU or BIOS doesn't it? The Motherboard & BIOS become one of the same so as far as I can see I have a 50/50 chance of guessing which one is the problem. Anybody for a calculated guess at the most likely? :) |
B.M. (505) | ||
| 516488 | 2007-01-16 21:20:00 | And an IDE cable plugged the wrong way will cause exactly those symptoms. | Graham L (2) | ||
| 516489 | 2007-01-16 21:53:00 | Have you taken the CPU out and reseated it? | trig42 (11325) | ||
| 516490 | 2007-01-16 21:55:00 | Update: Changed PSU and fault Remained . Disconnected power to DVD/CD Rom, fault remained . Virtually has to be Motherboard, CPU or BIOS doesn't it? A PSU will power a dead or faulty optical drive . It won't power up a drive if the PSU is faulty . I'd replace the RAM first then decide the MB is stuffed . Unlikely to be CPU . |
pctek (84) | ||
| 516491 | 2007-01-16 21:57:00 | Further update: Disconnected IDE cables but made no difference . What puzzles me is that with No Keyboard, No RAM, No IDE Cables (and consequently No HDD or DVD/CD Rom), and No PCI devices all the beeping is coming from me . :blush: Has anybody ever heard of a computer without POST codes? :confused: The other thing is, I have never seen a computer where the CPU fan doesn’t come on at start-up . Do they exist? :confused: The CPU is a 2 . 6ghz Pentium 4 by the way . |
B.M. (505) | ||
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