Monitor and USB port problems

coops53

Hey guys looking for some advice...

We have this old Tiny computer, I think it is nearing the end of its life but we would like to keep it going for as long as possible.

Just recently it has started showing a problem where the monitor does not recognise the computer i.e. if the monitor is on (standby) and you boot the computer up, the power light on the monitor remains on amber. If you disconnect the monitor lead the power light turns green and the screen displays some 'can't find signal' message.

Additionally, none of the (2) USB ports will power up the devices off them, leading me to suspect a problem with power to the I/O ports.

The computer itself boots up ok (I think.... it is difficult to tell without the monitor) and the lights come on. I have also had the side off and both fans function correctly as do both CD drives (power available)

Having had a look inside the computer I can see no trailing leads or signs of short/open circuits (no broken components or blackening)

Would appreciate your advice as to what the problem may be, or any other checks to carry out. Also do you think it is terminal as would like to repair the computer as cheaply as possible.

Thanks in advance.

Toxteth_OGrady

Almost certainly a hardware problem and could be any of:

1. Graphics card.

2. PSU.

3. CPU.

4. RAM.

5. Motherboard.


Very difficult to diagnose without spares and the machine to hand. You could try removing and reseating all components, power connectors and data cables.

:cool:

TOG

Cricri

Unless you try this monitor on another PC, and/or another monitor on this PC, you can't be sure as TOG said.
If the monitor doesn't work on another PC and another monitor works on this PC, I think we can confidently conclude that your monitor has a fault

Alternatively, did you try pushing the graphic card fully in its slot and trying again? Make sure to do so with power off of course.

coops53

Thanks guys, I have removed all connections within the computer and checked them, all seems fine. I have visually inspected the graphics card and it appears in good order.

I do not suspect the monitor as the power light turns from amber to green as soon as the monitor lead from the computer is removed. Therefore (to me) it appears that the correct signals aren't reaching the monitor. (I know very little about computers... but the monitor (when connected to the computer) is behaving like it does when the computer is shut down (amber light on monitor) therefore I assume the correct signal from the computer to the monitor telling it to switch on from standby isn't happening. I haven't seen a pin out of a monitor lead but must assume there is a power line that informs the monitor when to switch on???)

Also I do not think it is a PSU problem, as when you switch the computer on, there is obviously power from the PSU, through the switching unit(?) and to the motherboard as both the fans for the PSU and processor come on and the lights on the front of the computer are lit.

I believe it is probably a power issue to the input/output ports as the USB ports did not provide any power either. I know this because we have a USB mouse that would glow red if connected to the computer when on and it does not. Also we have a 4-way USB hub that does not light up when connected. I could not check the other ports as it is difficult without the monitor.

I have tried disconnecting all peripherals bar the monitor and this does not change anything.

Any more thoughts would be greatly appreciated

crox

I'm afraid if you don't know any techy/geeky types who'll have spares then you might need to take it to a computer shop.
I've never managed to tell by looking at a component if it's dead, the parts are just to small.

coops53

crox wrote:

I'm afraid if you don't know any techy/geeky types who'll have spares then you might need to take it to a computer shop.
I've never managed to tell by looking at a component if it's dead, the parts are just to small.

But what would I change? As stated this isn't just a monitor problem as the USB ports are providing power to the peripherals, unless the monitor problem is dragging down the other ports, the only thing I can see in changing is the motherboard.

Sorry, if this seems dumb, my computer knowledge is limited at best.

espresso

coops53 wrote:

But what would I change? As stated this isn't just a monitor problem as the USB ports are providing power to the peripherals, unless the monitor problem is dragging down the other ports, the only thing I can see in changing is the motherboard.

Sorry, if this seems dumb, my computer knowledge is limited at best.

I think that you mean are NOT providing power, as per post #4.

It sounds like it could be a PSU problem (5V rail), which I believe has been a common problem on Tiny PC's. This could be checked with a multimeter.

coops53

Thanks espresso, I did mean ARE NOT, I will try and lay my hands on a multimeter.

Any idea where the best place to check the rail is? I do not have a pin-out for the computer but I would think it is fairly generic. The main power lead to the motherboard has approx 20 pin(cannot check at mo) all of which are d-shaped connectors. I would assume the rails would be one of the outside pins (1,10,11 or 20 if it is 20 pin), but would this not mean the processor and fan would not power also, or are they supplied seperately?

Thanks again

espresso

This webpage may help regarding pin-outs.

coops53

excellent, thanks for the help