Need help with Acer M1200 desktop. Won't start.

Sidecar Bob · 06 Dec 2019

OK, I removed and re-installed the ram, unplugged & re-plugged the power connection to the motherboard (plug & socket both look good), then removed the C2032 battery and tested it. It was dead so I installed a better one.

Still no lights but at least now the fans don't start and the optical drive indicator doesn't light until I push the power button. But I can't turn them off except by pulling the power cord.

I tried the Knoppix CD and I tried a known good hard drive and it wouldn't boot from either.

And still no beeps.

FreeBooter · 06 Dec 2019

Power supply unit (PSU), problems can also cause lockups, unexpected reboots, intermittent boot problems, Blue Screen of Death errors, hard drive errors, or just plain won’t boot. I’ll explain how to test the PC’s power supply unit using a multimeter on your power connections and motherboard.

To begin the diagnostic process, verify that the PC is unplugged from the wall and is receiving no power.

Disconnect the power supply cables from all of the components inside the case. Follow each cable from the power supply to the component to make sure that everything is properly unplugged.

Short out pins 15 and 16 on the motherboard power connector with a small piece of wire. You can also use a paper clip to help test your power supply and trick it into thinking that it has been switched on. To do this, straighten a paperclip and then bend it into a “U” shape. This paperclip will act as the pins that are inserted into the power supply that give it the “Power ON” signal.

Find the 20/24 Pin connector that normally attaches to your computer’s motherboard. It is typically the largest connector for the power supply.

Find the green pin and a black pin (pins 15 & 16). You will be inserting the ends of the paperclip into the green pin (there should be only one) and a neighboring black pin.

Once you have placed the paperclip into each of the pins, Plug the power supply back into the outlet, and flip the switch in the back.

Once the power supply is receiving power, you should be able to hear and/or see a fan moving. If the power supply does not turn on at all, double check your pins (after unplugging) and try again. If it still does not turn on, then it is most likely dead.

Just because the fan is running does not mean that your power supply is supplying power to your devices properly. You'll need to continue testing to confirm that.

Turn on your multimeter and turn the dial to the VDC (Volts DC) setting.

If the multimeter you're using does not have an auto-ranging feature, set the range to 20V.

I recommend testing every pin on the 24 pin connector that carries a voltage. This will confirm that each line is supplying the proper voltage and that each pin is properly terminated. Connect the negative probe on the multimeter (black) to any ground wired pin and connect the positive probe (red) to the first power line you want to test. The 24 pin main power connector has +3.3 VDC, +5 VDC, -5 VDC (optional), +12 VDC, and -12 VDC lines across multiple pins.

Are any voltages outside the approved tolerance? If yes, replace the power supply. If all voltages are within tolerance, your power supply is not defective.

Below is a table listing the tolerances for each power supply voltage rail according to Version 2.2 of the ATX Specification.

Voltage Rail	Tolerance	Minimum Voltage	Maximum Voltage
+3.3VDC	± 5%	+3.135 VDC	+3.465 VDC
+5VDC	± 5%	+4.750 VDC	+5.250 VDC
+5VSB	± 5%	+4.750 VDC	+5.250 VDC
-5VDC	± 10%	-4.500 VDC	-5.500 VDC
+12VDC	± 5%	+11.400 VDC	+12.600 VDC
-12VDC	± 10%	-10.800 VDC	- 13.200 vdc

If your power supply passes your tests, it's highly recommended you continue testing to confirm that the power supply can operate properly under a load.

Turn off the switch on the back of the power supply and unplug it from the wall.

Reconnect all of your internal devices to power supply unit. Also, don't forget to remove the short out you have created before plugging back in the 24 pin motherboard power connector.

Plug in your power supply, flip the switch on the back if you have one, and then turn on your computer as you normally do with the power switch on the front of the PC.

Test the voltages for other power connectors like the 4 pin peripheral power connector, the 15 pin SATA power connector, and the 4 pin floppy power connector.

Just as with the 24 pin motherboard power connector, if any voltages fall too far outside the listed Power Supply Voltage Tolerances you should replace the power supply unit.

pepanee · 07 Dec 2019

Try this:
1) Plug in only one RAM stick. See if the computer turns on. If it doesn't, remove that RAM stick and put in a different RAM stick. Do this one by one for all the RAM sticks, (to cancel out the possibility that any of the RAM sticks may be damaged).
2) This may be a little challenging: Look at videos that show how to remove the CPU from the motherboard. Try removing it and re-inserting it back in the motherboard.

This is also what I would do:

[Plug in everything, one by one.]

First: Plug the power supply to the wall (all by itself, not connected to the computer at all), and try to turn that on. (I don't know if it turns on my itself or not, but I'm sure it should, since it just has power cables that go to the motherboard)

Second: Plug the power cables to the motherboard (the motherboard is all by itself, no hard drives connected to it, no RAM, nothing), and try to turn on the power supply.

Third: Plug in the RAM, plug in one RAM stick only for now.

Fourth: Plug in the hard drive to the motherboard, and see if the computer loads up.

ram1220 · 07 Dec 2019

If you returned to a black screen and now you don't get any beeps at all you have a bad CPU. It probably fried possibly due to heat when you were away from the computer. I just went through the exact same issue with my nephew's desktop. In his case he overclocked the CPU and the heat killed it. When he pushed the power button he would get some lights, fans would spin, and no beeps. I replaced the CPU and the desktop boots right back up. No issues.

joeandmarg0 · 08 Dec 2019

When the cmos battery fails,then the only feasible way of restoring the bios to the default stage,is to reinstall the bios by using the Acer cd,which if misplaced,should be downloadable from the Acer site.

Sidecar Bob · 08 Dec 2019

Freebooter: You had me worried for a while. I plugged a jumper wire between 15 and 16 like you said and the P/S didn't turn on. I had a funny feeling so I looked it up and the jumper needs to go between the PS-ON (green) wire and any black (ground). When I did that it turned on (P/S fan runs) and the voltages are all good both no load and with everything plugged in.

pepanee: None of your suggestions mad any difference either.

ram1220: I'm beginning to think you may be right. Unfortunately, I don't have a spare processor to test with.

joeandmargo: How would I do that? Just download the install CD from Acer on another computer, burn it and try booting from it?

pepanee · 08 Dec 2019

Yes, I believe that ram1220 could be correct.

You said that you were installing many Windows Updates on the computer. This computer has been offline for a long time I'm assuming? When was the last time that computer was in use?

See if you can go to your local computer hardware store (like Fry's Electronics, or whatnot, where you can return items for a full refund, just in case), purchase a new CPU (make sure it is compatible with your motherboard, with the amount of pins it has!!), and plug that into the motherboard, then turn the computer on. Assuming (and hopefully) the computer turns on, then the first thing you want to do is to go straight into the BIOS settings, and look for the option to restore all factory BIOS settings (to reset all the manual changes done to the settings, like overclock settings).

But before doing that, some motherboards may start up without a CPU. Try removing the CPU from the motherboard, and see if you can turn on the computer.
1) If the computer turns on (but doesn't have to load anything else), then it very likely would be a CPU issue.
2) If the computer doesn't turn on, then it is still inconclusive since this motherboard would probably require a CPU to turn on.

FreeBooter · 08 Dec 2019

Sidecar Bob said:

Freebooter: You had me worried for a while. I plugged a jumper wire between 15 and 16 like you said and the P/S didn't turn on. I had a funny feeling so I looked it up and the jumper needs to go between the PS-ON (green) wire and any black (ground). When I did that it turned on (P/S fan runs) and the voltages are all good both no load and with everything plugged in.

pepanee: None of your suggestions mad any difference either.

ram1220: I'm beginning to think you may be right. Unfortunately, I don't have a spare processor to test with.

joeandmargo: How would I do that? Just download the install CD from Acer on another computer, burn it and try booting from it?

I did say Find the green pin and a black pin (pins 15 & 16). You will be inserting the ends of the paperclip into the green pin (there should be only one) and a neighboring black pin.

Sidecar Bob · 08 Dec 2019

Yes you did and now that I'm looking specifically for that I see it. But you also said "Short out pins 15 and 16 on the motherboard power connector with a small piece of wire." a couple of paragraphs earlier and that's what I read when I was trying it..

I knew the P/S should turn on, though, because when I push the power button on the front of the case the fans start running, and that's what worried me. Anyway, no harm done.

BTW: I understand that you suggested a paper clip because a non-technical person is more likely to have one but I'm glad I used an insulated wire jumper (similar to shown in your pic) because when I let go of it to plug in the power cord the connector moved and the middle of the jumper rested against part of the case. I don't think that would have done any harm since the object was to short the green wire to ground anyway but but I am still more comfortable using something insulated (years of house wiring and working on motorcycles I guess).

And with the processor removed it does exactly the same thing: The P/S and processor fans start but nothing else happens.

The AMD Athlon LE1640 that is a pretty old chip and has been out of production for years so I don't think there's a computer place near here that is likely to have one, let alone let me buy and return.It.

I'm starting to think this machine has reached its end of life. Too bad; Aside from its operational limitations, it is a nice one with lots of front panel USB ports and other nice features plus it was the last one my son set up before he died.

joeandmarg0 · 08 Dec 2019

Re your post 16,yes use any other computer to download and burn the install cd.Make sure you have all the necessary info to obtain the correct installation.Good luck.

- - - Updated - - -

Forgot to mention,if you have an Acer bios,then it can be restored after pressing the power switch,by pressing and holding the F10 key and if you hear TWO [2] beeps the settings have been restored.No guarantees.
The other keys for Acer computers,not acer bios's,are F2 and DELETE