Computer Repair Help

[KingSeti]

Hello to everyone!

I would like to post a computer issue i am having and hopefully get some help, or direction, as to what i can do to possibly fix the issue. I hope I posted in appropriate section and appologize if i have not. Let me start by saying it is a dell desktop, model dimension 4700, that was given to me to do a format and recovery on. My friend told me he had a couple virus's on this computer and asked for me to just recover it for him (xp home). Only problem is that sometimes it would power up and sometimes it would not, hence the thought of virus. I figured no problem I would mess with it to see what I could do for him. I put the disk in and after a couple of times of turning on and off and on and off I got it to boot and do the recovery. When all was said and done it ran as long as the computer fired up. So to dig into why it will not turn on or do anything when I pushed the power button, I unplugged the two dvd drives, the floppy drive and the one pci card that they had installed (and i think i unplugged the front usb ports as well) and when I hit the power button I just get a power light. It has two memory chips and I removed them one at a time as well. All that is left hooked up is the processor, fan and memory. It will not boot to anything, just the light comes on. Since I have elimated extras (two dvd drives, floppy and the pci card) what else can I look for as to the cause of the problem? It has been sitting for a couple of months and I do not remember if it gives any beeps for errors. I will set it up tonight when I get home and try and fire it up and report back if any beep codes are given. I thought I would get a head start and post some information to get some thoughts going.

Here are the specs from dell site:

System Type: Dimension 4700
Ship Date: 11/20/2004
Dell IBU: Americas

Quantity Parts # Part Description

0 4X388 Instruction, Preparation- Material, Deviation, Dimension Increase, Number
1 C3826 Processor, 80547, Pentium 4 Prescott DT, 3.2GHZ, 1 MEGB 800FSB, SKT-T
1 2R400 Keyboard, 104, 6P, United States, Multi-Media, NMB...
1 D1161 Kit, Mosue, UNIVERSAL SERIAL BUS..., 2 Button, Wheel Optical, PRIMAX ELECTRONICS LTD...
1 N1818 Kit, Speaker, 120V, A425, Zylux Corporation, Dell Americas Organization
1 X2749 Modem, V.92, Data Fax, Internal Donny, Dell Americas Organization
1 Y6401 Assembly, Digital Video Disk Drive, 16x, Hh, Samsung, CHASSIS 2005...
1 T7404 Assembly, Dvd+/-rw, 16X, Half Height, Philips, CHASSIS 2005...
1 M1210 Assembly, Floppy Drive, 212, 2
1 T4340 Hard Drive, 160GB, Serial ATA 7.2K, 8MB, Maxtor Calypso
1 T7166 Kit, Software, WP-PRDCT-STE12 English, V2
1 H8412 Kit, Software, Overpack, WXPHSP2 Compact Diskette W/Documentation English
1 P7128 Kit, Documentaton On Floppy Disk, Software, POWERDVD..., 5.3
2 G5451 Dual In-Line Memory Module, 256400M, 64X64, 8, 240, 1RX8
1 D7509 Display, Flat Panel Display, 17 Dual, E173FPVF, Dell Americas Organization, FLAT PANNEL IN BOX...
1 P3984 PLACEMAT..., GETTING STARTED..., DIM4700, DAO/BCC
0 83535 INFORMATION..., PART, ADVANCED TECHNOLOGY ATTACHMENT PACKET INTERFACE..., DEVICE
0 83535 INFORMATION..., PART, ADVANCED TECHNOLOGY ATTACHMENT PACKET INTERFACE..., DEVICE
0 01323 INFORMATION..., NO ITEM
1 K3490 Assembly, Chassis, 212, 305W, Non PFC, PWA Integrated
1 M5050 Assembly, Heatsink, Mainstream 212, Dimension
1 W5457 Assembly, Shroud, Plastic, 4700 Mainstream

If anyone can give me some advice as to what I can do or look at from here I would really appreciate it, as this computer is like brand new sitting in my little work room. As I have mentioned, when I can get it to start up it runs no problem. The only problem is when you shut it down it might not start again. I appologize if I have not given enough information (just let me know what other information you would like) but I kind of forgot about the computer till my wife asked Saturday if i was going to throw it away. She does not keep stuff like i do! It then hit me to try here! i figured I get all my video help from here why not try actual computer help.

Thanks in advance if anyone can help me with this issue.

[aedipuss]

the first thing i would try would be a known good power supply of at least 500 watts.

[stiltman]

the first thing i would try would be a known good power supply of at least 500 watts.

However Dell uses a proprietary PSU on the major it of their computers. Pluging in a normal ATX PSU into a Dell can fry the MB

[TBoneit]

Look on the back there should be 4 diagnostic lights in a row. Once you have them located they will help you determine the problem.

This link is for the Dell service manual.
http://support.dell.com/support/edocs/systems/dim4700/sm/adtshoot.htm
Also look for any bulging capacitors on the Mobo, http://www.badcaps.net/ for more info.

It won't boot until all four lights turn green on a Dell.

Good Luck

[usually_quiet]

If the PSU is possibly the problem, you should know that the pin-out of the motherboard's power connections on Dells was changed to the standard ATX arrangement, sometime prior to 2001.

What still wasn't standard was the back the cases. They have cut-outs that match where the plug and exhaust fan on their power supplies are located. There's no cut-out for an on/off switch (Dell PSUs don't have one), and perhaps the holes for the mounting screws aren't all in the same spot as usual. That's why people must still buy a specialty PSU made for Dells. Either that or do surgery on the back of the case when they replace the PSU.

[stiltman]

I stand corrected
http://en.community.dell.com/forums/t/19281822.aspx

Also
Pentium 4 Dell Models that do not require a power supply adapter:
Dell Dimension 4300, 4400, 4500, 4700, 8200, 8300, OptiPlex GX 400

[usually_quiet]

I stand corrected :)
http://en.community.dell.com/forums/t/19281822.aspx

Also
Pentium 4 Dell Models that do not require a power supply adapter:
Dell Dimension 4300, 4400, 4500, 4700, 8200, 8300, OptiPlex GX 400

Good. I see on the linked page that the back of the case where the PSU sits is open on the Dimension 4700 too, like a normal case. I have an earlier model in the Dimension series that is not open. It just has cut-outs for the plug and the exhaust fan.

[redwudz]

I would probably agree to try a different PS if you have one available. If not, and a PS isn't the problem, look to the MB connections. Make sure they are all secure.

From there, I would probably hook up one of the optical drives and set BIOS to boot from them. You can try a Linux distro that will boot and run from disc or a Windows PE disc. (Info here) http://www.nu2.nu/pebuilder/ You may also find a pre-made one on the net. Starting from a disc like this should rule out the OS as a problem if it doesn't work.

From there it's usually a hardware problem. If it isn't RAM or the CPU, then the motherboard would be suspect. You need to be methodical to eliminate all the common causes.

[KingSeti]

Wow, thanks for all the replies guy's! Just to finish off what I had said I would do when I started the post, I dug it out last night and plugged it in and here is the details. I left everything hooked up (both dvd drives, pci card and floppy drive) and pushed all conections to make sure they were secure. I did this with all cables (even power) to both dvd drives, floppy, hard drive front usb . . . whatever I could. I pushed the power button and it fired right up. However, that was about 6 1/2 hours ago, and the computer is froze. i tried ctrl-alt-del and I get no response. I fired it up at about 11 (EST) last night and it did updates to the antivirus, I surfed the net for about a half hour and periodically check it for about 45 minutes later. I then went to bed. I went over to it to move the mouse this morning (screensaver was left on) and no response. I do have Everest Home Edition installed on this computer and I checked the temperature before I went to bed and it was at 127 F. However, i do not remember what the sensor was (sorry i was tired). I will try and restart the computer before i go to work and get into everest and see what the sensor is.

i do appreciate all the responses! oh, one other thing, when i did start it up i had on the screen a message that said

Alert! Previous fan failure
Strike the f1 key to continue, 2 to run setup utility.
There were 2 beeps.

i hit f1 and it booted up.

i will also check the 4 lights after work, as it stands now while it is froze there are 4 lights (a, b, c and d) and they are all green. The psu fan is running and the processor fan is also running. i have the side panel off, i took that off last night before i went to bed when i seen the temp at 127. I will unplug everything this time and just go with fan, hdd and memory.

[KingSeti]

Quick Update! I shut the computer, opened case, unplugged both dvd drives, floppy and pci card. Pushed all connection to make sure all was seated properly then plugged in and pushed the power button. All I have now is a really high pitched fan, processor fan, that sounds like it is going to explode. I shut it down, unplugged and pused the power button to realease charge that might hvae been left, unplugged and re-plugged the processor fan, no dice, still wants to explode. Waited a few minutes and tried again, this time i got the screen to accept changes (since i unplugged everything) hit f1 then i got 2 beeps and the light codes on the back show green, green, green and yellow (a, b and c are green and d is yellow). Which in the link above (TBoneit) jsut say's "another failure". I also looked at all the capacitors i could see and they all look good. While it was trying to boot, all the color codes kept changing but finall stoped on the one i mentioned.

So, to update, nothing is hooked but one memory chip, processor fan and harddrive.

I have an appointment in a little so i will not get to mess with it for the next couple hours. if i think of anything else i shall report back. if anyone else has anything i could try i shall do that as well.

[aedipuss]

sounds like it is overheating. the fan warning and noise of the fan suggest it may have a bad bearing and it seizes when it gets hot. i'd try a new hsf and some artic silver 5.

[KingSeti]

Well, I just can't get it to fire up now. Just to keep things straight, I have the tower laying on its side next to me (in order to see inside) so I can post updates on the situation. I have side cover off, no power to both dvd drives (burner and a rom), no power to floppy drive and nothing in the pci slots and the front usb ports unhooked from mother board. Memory slots has a 256 in slot 1 and a 256 in slot 3. I have pushed on all connections to make sure they are all seated.

I have a question on the psu, since it was running is it still possible that it is bad? Also, is it possible that the cpu is fried, well not fried but getting there? I can't seem to figure out how to get the heat sink fan off the processor so that I can remove it and have a look.

Redwuds, I will try a linux distro here in a bit.

[redwudz]

If you plan to pull off the CPU heatsink, be very careful. The CPU is often stuck to the heatsink and may come off with it. Warm up the heatsink by running the computer first or using a hair dryer. When you do pull it off, pull straight up, no twist, no tilt. Even if the CPU sticks to the HS, it should be OK with no damage. Check for bent pins, then try using a plastic card to separate the CPU from the HS. Avoid touching the pins. Clean off the old HS compound with something like isopropyl alcohol, 100% or denatured alcohol. Then apply a thin layer of new heatsink compound and put it all back together. The original HS compound is probably hardened in mostly ineffective anyway. If you don't feel comfortable with this whole process, skip it.

If the CPU fan is dodgy, you may be able to replace it with the cooler still attached to the CPU and motherboard.

Go ahead and try booting it from a different OS. Then you may know if it's a software/OS problem.

But from the rest of your posts here, I would still suspect the power supply. Unfortunately the best way to find out is to replace it. So you have a 50/50 chance that it cures the problem.

Usually CPUs work or they don't. Occasionally part of it can fail, but more often the motherboard is the problem as it has a lot more parts that can fail.

[KingSeti]

Ok, still stuck at a non booting computer. Got up this morning and pushed the button, no dice, fan still wants to explode! I did however plug in the dvd-rom, pop open the tray and put a linux distro in. I plugged it back in and tried to power up and still an extremely loud fan and nothing happening. I will try again when i get home from work tonight.

aedipuss, you mention bearings seize when it gets hot, fan was running while the computer was froze the other day. That is also why I dont think it is power supply related because the computer was just froze. If power supply is bad wouldn't it have shut the computer down? i'm not questioning your knowledge but my lack of understanding how psu could be bad if the computer was on, and the fact that i get lights but it will not boot. I know i have an extra power supply in my box of "extra's" (he say's quietly so the wife dont hear) and see if i can try it with this dell.

Redqudz, after reading that (above about removing processor), I am not sure i even want to try and take it out! For the life of me, I can't see how to get them off the motherboard. I mean I see not clips to unlatch.

So is there a way I can test ram or cpu since I can't get it to boot up? Or if I do get it to boot up what should I do to narrow it down to the culprit that is causing me problems?

I just printed out everyone's reply so that I can read it over before I get home tonight. I'm still hoping!

[TBoneit]

MY best guess is that the computer has a bad motherboard.\

If you search the web for Dell & high speed fan, racing fan etc you'll see that usually means the Mobo is toast.

I have a couple of GX280s here with the same symptom. The fan just keeps picking up speed until it is running really fast and noisy. I did find one site that offered to replace the bad part with about a 50% success ratio and it would still cost something to try.

[loughary]

I'll throw my 3 cents in...I had a friends that had a similar problem and it turned out to be a bad video card...his Dell had a video card built in to the motherboard that was disabled and it was using the AGP slot for video.

Check and see if is has video port on the motherboard and if so unplug the video card from the AGP or PCI slot and try using the integrated video...you may have to tell your BIOS what video to use as default as well. I thought that system comes default with integrated video and you could upgrade the video to a actual card.

Worth a shot...his would do the same thing randomly work and at times it wouldn't.

[aedipuss]

aedipuss, you mention bearings seize when it gets hot, fan was running while the computer was froze the other day. That is also why I dont think it is power supply related because the computer was just froze. If power supply is bad wouldn't it have shut the computer down? i'm not questioning your knowledge but my lack of understanding how psu could be bad if the computer was on, and the fact that i get lights but it will not boot. I know i have an extra power supply in my box of "extra's" (he say's quietly so the wife dont hear) and see if i can try it with this dell.

ok if the fan was still running when it died, it most likely isn't a bad hsf. still check to see that the heatsink fins aren't all clogged up with dirt and dust.

test it with the spare psu, you don't even have to install it. just disconnect the old one's cables and hook up the spare from outside the case. if that doesn't help... i'd side with the motherboard is dead guesses.

[Bjs]

after reading that (above about removing processor), I am not sure i even want to try and take it out! For the life of me, I can't see how to get them off the motherboard. I mean I see not clips to unlatch.

Dimension 4700 Service Manual guide

Yes, power supplies can still operate motherboard, fans, drives ... it depends on the failure.

Normally take the motherboard completely out of the case and try with a known working psu ... with only gpu and keyboard attached ... and floppy if available ... if it fires up try a bios flash update as last resort ... if symptoms do not clear the motherboard should be replaced.

Had one go nutts because a retaining screw had become loose between board and case shorting the board ... replaced.

[KingSeti]

Guy's and Gal's, sorry for not posting in a few day's but i had some other issues develop. These were however not computer related! Everything should be fine in which I can get back to this computer issue. I have tried about 30 times in the last 3 days and it still wont do anything but sound like it wants to blow up. I am going to take the power supply to be checked as the power supply I thougt I had I can not find. I probably gave to a friend or something months back.

Bjs, thanks for the link to that manual. I have copied it into word (to save a copy) and will pull out the processor as well. I do believe they can check them!

Loughry, it has integrated video. As I said, I have everything out of this computer except the dvd rom with a linux disk in it to try and boot from, as redwudz has suggested.

As it stands, nothing in pci slots, no floppy hooked up, no dvd writer hooked up and front usb disconnected, only items left are 1 stick of memory, harddrive, dvdrom with linux distro in it and the processor. I have pulled out the power supply and will try and make it to a computer shop this afternoon to have it tested.

I WILL NOT BE TAKING IT TO THE GEEK SQUAD EITHER!

I will take it to John Doe Computer's down on the corner first!

As soon as I know you all shall know!

[KingSeti]

To all those who said power supply, thanks a million! I had my wife take it yesterday and the tech told her that it was bad, they check them for free. His explanation is that the "negative 5" volts failed and it is not mirroring or matching the "positive 5" volts. I have no clue but you guys might! He said he could test the processor for 25 bucks but I told her to use her judgement and if it was reasonable to have it done. She decided not to as I had explained to her I could get a power supply for 35 to 40 and if it did not work then I would have a backup power supply and then know that it was the processor that was at fault. I have a coolmax power supply on order and should have it in a few days, will post back as to what happens.

Once again, thanks to all for your help. I thought the motherboard was a goner and would have never thought the power supply would work intermittant like this.

[KingSeti]

Ok guys and gals, I give up! I still had my doubts that it was the power supply. I just hooked it up, just the processor, memory, dvd-rom with a linux distro and harddrive. Pushed the power button and the same thing, the fan really loud. This time however, no lights on the back of the tower, at least the old power supply showed the 4 lights on the back. The new power supply is a coolmax atx v2.01 400 watt, model v-400. The one that came out was 305 watt.

So now what would you guys do? I am ready to throw it out the window. This is why it has been sitting in the corner for so long. Would it be worth it to have the processor checked for 25 bucks?

[aedipuss]

probably not for a p4. i'd toss everything but the hard drive.

[redwudz]

The -5VDC rail doesn't do much anymore and is optional in newer computers. It was used in older computers for ISA cards and a few rare peripherals. Probably wouldn't have much if any affect if it didn't work. I think you are looking at a failed MB or CPU, with the MB being more likely. The CPU probably isn't worth testing.

Maybe time to replace the MB with a Micro-ATX MB with on-board video, an inexpensive CPU and RAM. But you're probably looking at $100US or more. Alternately a bare-bones kit with case, PS, CPU, RAM, MB and reuse the drives.

[MJA]

did you check the MB for bad capacitors?

it's very easy to change the caps,and cheap too

http://www.badcaps.net/forum/forumdisplay.php?f=20

[KingSeti]

Yes, I did take a look at the capacitors per the posting above from Tboniet. They all look good, at least from what i can see. I might take a gander at motherboards on TigerDirect.com, anyone point me to some good ones to look at. Like redwudz said, either 100 for possible mobo and processor or barebones kit and reuse some of the drives.

[freebird73717]

tigerdirect is okay but also check newegg.com

They've got some motherboard/processor combos.

[usually_quiet]

If you are planning to re-use the Dimension 4700 case, check to make sure a replacement board will fit and can be connected to the power/reset button. case LEDs, front USB and front audio ports.

I have an earlier model in the same series, a Dimension 4300. There are some things about that case and motherboard that make it difficult to re-use. The motherboard's form factor is non-standard. It has 5 expansion slots, not 4 or 7. The motherboard is mounted on posts and held in place by clips on the board, instead of being attached with screws. Also, the posts don't line up with the holes on a standard motherboard.

In addition. a single cable incorporating the front panel connections, front audio ports, and front USB ports runs from a daughter card located in the front of the case to a non-standard header on the motherboard. I don't know of a way to use the front USB or front audio ports with another motherboard, and an adapter cable would need to be purchased to connect the power button/reset and LEDs to a standard motherboard.

[classfour]

King: Are you certain it's not memory? I recently replaced the memory on a "near-new" Dimension E520. I had the thing for a week, ran a Soyo Diagnostics card on it; checked the codes at Dell's website, etc.. I had the BSOD within twenty minutes of booting; scanned the HDD for errors, viruses, etc., hoped it wasn't the processor. In the end I pulled one stick and booted with the other - and it booted GOOD. Replaced all the memory in the thing with some surplus that I had - I really didn't want the thing coming back an staying a week. Ran it for two days straight without an error. I don't know if I'd pay someone to check a P4: You may be into expensive territory there.

[Nelson37]

Eliminate the Hard drive and DVD-ROM. Not necessary to get a valid power-up and if shorted, could be the cause of the problem. This would be the "ISOLATE" part of ISOLATE and IDENTIFY. Remove power AND data cables, unplugging the data cable from the mobo. Yes, the data cable can short and cause a failure to boot.

"testing" a power supply is a worthless waste of time. For not much more than the $25.00 spent, you could buy a new power supply and connect and test in about two minutes. A good power supply will boot the box, a bad one will not. That's all you need, anything else is BS. As mentioned, a bad PS can power fans and still fail to boot.

A virus will absolutely, positively NOT repeat NOT cause a failure to power up. That is a hardware issue, period.

I would also remove the front panel header and switch on by manually shorting the two pins. Could be something as simple as a bad switch.

The proprietary connector for the USB is no problem for re-using the case, just don't use it. Isolate the two wires for the power switch and either break the connector, or cut and splice the wires to a standard connector. Questionable whether re-using the case is worth the hassle.

[usually_quiet]

I might take a gander at motherboards on TigerDirect.com, anyone point me to some good ones to look at. Like redwudz said, either 100 for possible mobo and processor or barebones kit and reuse some of the drives.

It would be good to know what kind of tasks the computer will be used to do before making a recommendation, but if you are looking for something that is very basic and inexpensive, there's this pre-assembled bare-bones kit for $100 US
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4959277&csid=_21

It has this motherboard http://www.msicomputer.com/index.php?func=proddesc&maincat_no=1&cat2_no=&cat3_no=&prod_no=1449

The kit lacks a CPU, memory, and drives. It has a VGA port, 2 PS/2 ports, 4 USB ports, a parallel port, a serial port and on-board LAN. Onboard graphics are DirectX 9. Motherboard supports 2 EIDE devices, 1 floppy and 4 SATA devices, and up to 4 GB of memory. The PSU is only 250 Watts, so it may need to be replaced with something more powerful, depending on what is added.

For $200 US there's this bare-bones kit: http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5343969&CatId=333

It has better on-board graphics, and includes a CPU, as well as a 1 stick of memory. It has a better PSU too, but it could still need a higher wattage power supply depending on what else is installed.

For either option, you'll probably need to purchase a new OS too. With Dells, the OEM licensing for the OS purchased with the computer is tied to its motherboard. The license for the OS is not valid for any motherboard but that one.

Compare these options to an inexpensive new or refurbished Dell system, and decide what is better. There are some advantages to both . When someone builds a PC, they have more choice regarding components, know more about them, and there's no crapware to deal with. On the other hand, if a pre-built PC is purchased, someone else does all the work of finding compatible parts and assembling them, plus it's going to be functional right out of the box.