Presario 6000CL board has ringing or oscillating noise and freezes

[axlmastr]

I've been repairing some boards here and there. Mostly scrapping anything under 1.0 GHz now. Good money in e-scrap. Been working on those Dell SX also. What a piece! Still doing Optiplex/IBM SFF PSUs

Anyways this Compaq is not much different from the crap Dell makes. Presario 6000CL w/XP Home SP2. MB is a A7V8X-LA w/o the latest Compaq BIOS upgrade installed. The XP2800 proc is gone for an Athlon 1400. Memory is 768MB DDR266 tested with Memtest. WD 180GB PATA tests Good with Spinrite and DFT. Fairly new PSU is questionable- Austin 300W ATX showing rated for 280W/180W 12V/5V 3.3V. This is how I got it handed to me.

The board is populated with TEAPO instead of the usual OST/Elite/United -Chemi. There's only three caps that are United-Chemi 1200uF 16V. When machine appears to be under load (booting/downloading updates from web for example) a high pitched ringing or oscillation emanates from the board in or around the backplane behind the I/O header. While booting, if the blue dotted line in the XP splash is scrolling it will stop quick every time this sporadic noise is heard then continue. The machine will boot up to a desktop and be fine for about 5 min. or so and then it will just freeze requiring a reset. It will freeze just idling with anitvirus and software firewall running in systray and thats it. If I download something from the web it may or may not freeze part way through. Just wanted to know your thoughts on this one. Should I bother to recap this one? It has a lot of headers for USB/1394/SATA. I'm using the onboard video and have swapped the PSU with a known good Antec. The PSU mad no difference.

Thanks in advance


P.S. Is there anyway to search a particular board or machine model or brand in this forum once you reach the desired section? It would make it easier to see if someone else has a similar issue with the same component/brand/model.

[kc8adu]

Re: Presario 6000CL board has ringing or oscillating noise and freezes

always post a pic.
many oem boards are something common that someone has seen before and knows the pattern failures.

[Scenic]

Re: Presario 6000CL board has ringing or oscillating noise and freezes

had something similar on a compaq machine a while ago.
board was a MSI K7T Pro 2 (MS-6330).
same symptoms..
after replacing all VRM Teapos with pannys and a few bulging chhsis it worked fine again.
worked fine before in my little brothers pc. at least until he upgraded his graphics card from an ATI Rage 128 to a Radeon 9600..

looks like this upgrade (power hungry gfx card (radeon 9600 compared to the rage128)) finally killed those crapcaps..

[chipper]

Re: Presario 6000CL board has ringing or oscillating noise and freezes

I've been repairing some boards here and there. Mostly scrapping anything under 1.0 GHz now. Good money in e-scrap. Been working on those Dell SX also. What a piece! Still doing Optiplex/IBM SFF PSUs

Anyways this Compaq is not much different from the crap Dell makes. Presario 6000CL w/XP Home SP2. MB is a A7V8X-LA w/o the latest Compaq BIOS upgrade installed. The XP2800 proc is gone for an Athlon 1400. Memory is 768MB DDR266 tested with Memtest. WD 180GB PATA tests Good with Spinrite and DFT. Fairly new PSU is questionable- Austin 300W ATX showing rated for 280W/180W 12V/5V 3.3V. This is how I got it handed to me.

The board is populated with TEAPO instead of the usual OST/Elite/United -Chemi. There's only three caps that are United-Chemi 1200uF 16V. When machine appears to be under load (booting/downloading updates from web for example) a high pitched ringing or oscillation emanates from the board in or around the backplane behind the I/O header. While booting, if the blue dotted line in the XP splash is scrolling it will stop quick every time this sporadic noise is heard then continue. The machine will boot up to a desktop and be fine for about 5 min. or so and then it will just freeze requiring a reset. It will freeze just idling with anitvirus and software firewall running in systray and thats it. If I download something from the web it may or may not freeze part way through. Just wanted to know your thoughts on this one. Should I bother to recap this one? It has a lot of headers for USB/1394/SATA. I'm using the onboard video and have swapped the PSU with a known good Antec. The PSU mad no difference.

Thanks in advance


P.S. Is there anyway to search a particular board or machine model or brand in this forum once you reach the desired section? It would make it easier to see if someone else has a similar issue with the same component/brand/model.

I never did like 266mhz memory , seemed to be a problem waiting to happen if you could run 333mhz , especially if you are trying to run the board or anything at peak. My 266mhz memory on my Presario leaked and was always running low , to the point where I installed a RAM MAX of some sort , but it just interfered with the ram more by resetting it , so I installed the Crucial 256mb x 2 ram chips for stability. Been good ever since. Sounds like the fan may be due for a change from when the ram is needed , the fan can change speeds. You can unload the taskbar , I used to do that all the time to save ram and see if the fan doesn't squawk. Learned that from the ram monitor showing me the exact ram usage , and tweaked it with it to run anything. Sometimes the 266mhz@256mb ram left me with 20mb of ram running to spare.

[PCBONEZ]

Re: Presario 6000CL board has ringing or oscillating noise and freezes

I think your VRM MOSFETs are ringing due to bad caps.

[axlmastr]

Re: Presario 6000CL board has ringing or oscillating noise and freezes

I'm going to go ahead and recap it with some pannys and see what happens. Hate to scrap it since it has firewire on it.

To chipper: The box originally came to me with 333MHz memory and had the same problem. I even substituted my own 333MHz to see if it were a difference. No change. I would agree that the VRMs are singing but the three largest sized and valued caps were united-chemicon located between the proc and the backplane. The rest were teapos.

BTW- If anyone is having problems with Dell Optiplex GX50 or 150 check the PSU caps and fan. I replace them all of the time. The PSU fan can be replaced with a standard three wire fan after the header shroud is removed from the PCB. An error message on POST about the fan will appear afterwards, so F1 to continue and all is well.

Thanks

I will post results after recap.