OK PC geeks

Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Hi peeps....Well I have customer with a funny problem in an HP Lenovo ThinkCenter M92

It has a start up problem, it will power cycle on and off on and off till the AC power plug is pulled, try and restart it and it will do the same.

I have tested the power supply, changed RAM, changed the hard drive (after cloning it) and even the DVD player, they test fine in another system so they are all OK.

The only way to start it up and get it to boot is to first remove one of the RAM sticks, (weird) then power it up, it then will boot fine...But...Till you power it down and restart it, it then goes back into the power up/down cycle problem.. Pull the power cord and re-install the RAM stick it will then boot just fine, until the next power down...Then the problem comes back.

I'm beating my head against the wall on this one kids.....
 
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Joined
Jan 1, 2000
Messages
35,613
Reaction score
8,581
Points
113
Age
59
Website
www.sat-elite.uk
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK
Is the bios up to date ?
 
Analoguesat

Analoguesat

Administrator
Staff member
Joined
Jul 26, 2003
Messages
50,798
Reaction score
11,253
Points
113
Location
Scottish Borders
My Satellite Setup
TM 5402HD
Sky+ UK.
My Location
Scottish Borders
Weak power supply or faulty mobo?
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
Had one recently with similar symptoms. Check power and reset switch connections to the motherboard. If you don’t have spare switches try swapping them in. If not just short the power and the reset switches to replicate the same function. Removing the memory bank may just be giving out enough power for the PC to boot.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Analoguesat said:
Weak power supply or faulty mobo?
Click to expand...
MB hummm, once I get it to boot up it works fine, I have no way to test this type of PS, it has a 14 pin connection to the MB.

Both the new and old ram do the same thing, power up then power down, will do that forever untill I pull the power cord. Pull a ram stick and power back up it boots fine.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Satspot said:
Had one recently with similar symptoms. Check power and reset switch connections to the motherboard. If you don’t have spare switches try swapping them in. If not just short the power and the reset switches to replicate the same function. Removing the memory bank may just be giving out enough power for the PC to boot.
Click to expand...
If I use 1, 2, 3 or 4 sticks it still does the power problem, I have to pop one out to get it to boot after the problem.
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
Terryl said:
If I use 1, 2, 3 or 4 sticks it still does the power problem, I have to pop one out to get it to boot after the problem.
Click to expand...
That’s why I suggested trying the power switch and the reset switch to see if they were faulty. Faulty switches can reproduce some real weird behaviour on a motherboard. The constant switching on/off of switches can cause bad contacts and intermittent faults across a whole range of components. If you have access to spare push on/off switches just swap them in. If you don’t just cross the relevant pins on the motherboard to replicate the switching action of the switches. Leave all the components connected while doing this. If your RAM was bad you should have picked this up on the POST. Audible beeps will alert you on power up. Try the switch solution. It’s the cheapest option by far.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
I will check the scrap pile for any PC switches
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Terryl said:
I will check the scrap pile for any PC switches
Click to expand...
Well no switches to be found, but....I did test the one on the PC with a continuity tester, and I did a resistance check, it tests out fine.

I have run a complete system test downloaded from the manufacture, it ran every test you can think of, ram, CPU, motherboard, hard disk, DVD player SATA connections, USB ports and anything else in that PC, all tested out fine....

The only thing it could not test is the power supply, and I cant test it as it has a 14 pin main motherboard connector, my power supply tester has the standard 24 pin, I have ordered an adapter cable (24 pin to 14) to try a standard PC power supply, (I have several good ones lying around) if that works then it's a google search for a replacement PS.


I hope this is the problem as I'm getting quite tired of working on this one, and I really cant give it back half working.
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
Terryl said:
Well no switches to be found, but....I did test the one on the PC with a continuity tester, and I did a resistance check, it tests out fine.

I have run a complete system test downloaded from the manufacture, it ran every test you can think of, ram, CPU, motherboard, hard disk, DVD player SATA connections, USB ports and anything else in that PC, all tested out fine....

The only thing it could not test is the power supply, and I cant test it as it has a 14 pin main motherboard connector, my power supply tester has the standard 24 pin, I have ordered an adapter cable (24 pin to 14) to try a standard PC power supply, (I have several good ones lying around) if that works then it's a google search for a replacement PS.


I hope this is the problem as I'm getting quite tired of working on this one, and I really cant give it back half working.
Click to expand...
Don’t think those power supplies are cheap to replace. Proprietary as far as I remember. It still sounds like a short somewhere. Was there any PCI/PCIe cards added at any stage or any other items that may be drawing too much power on boot. Try reseating any cards in the expansion slots. Was a graphics card added at any stage.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Satspot said:
Don’t think those power supplies are cheap to replace. Proprietary as far as I remember. It still sounds like a short somewhere. Was there any PCI/PCIe cards added at any stage or any other items that may be drawing too much power on boot. Try reseating any cards in the expansion slots. Was a graphics card added at any stage.
Click to expand...
No other cards in the system, it's all stock...

And I did find a power supply for it on Ebay, (cheap also) it should be here on the 1st, tested and guaranteed or my money back. ( I just hope thats the problem)
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
While you’re waiting just make sure all the connections to the motherboard are firmly seated particularly the I/O headers. Are all those excess unused cables from the power supply well secured and in good condition. No chance that any are touching ground.
 
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Joined
Jan 1, 2000
Messages
35,613
Reaction score
8,581
Points
113
Age
59
Website
www.sat-elite.uk
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK
Just checking you haven't left a DVD/CD/SDcardfloppy in one of the external ports.

Is the boot up set to look at hard drive first ?
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
No nothing in the DVD drive, and I even pulled it out of the system as a test, and nothing in any of the USB ports, yes it is set to boot from the hard drive, boots fine after messing with a ram stick, all ram tests out fine, all 4 of the slots test out fine, this was tested with the software downloaded from the manufactures customer service rep.

Nice test too bad I cant use it on other PC's, it was only meant for this one.
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
Terryl said:
No nothing in the DVD drive, and I even pulled it out of the system as a test, and nothing in any of the USB ports, yes it is set to boot from the hard drive, boots fine after messing with a ram stick, all ram tests out fine, all 4 of the slots test out fine, this was tested with the software downloaded from the manufactures customer service rep.

Nice test too bad I cant use it on other PC's, it was only meant for this one.
Click to expand...
It’s an HP. You get what you pay for. Still providing bios updates for machines in excess of 10 years old. Not too many manufacturers doing that these days.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
OK kid's I fixed this one with a motherboard replacment, all is well and the PC is 1000% faster with the new SSD drive then with the old hard drive.
 
S

Satspot

Member
Joined
Sep 3, 2021
Messages
587
Reaction score
199
Points
43
Age
61
My Satellite Setup
Technomate TM5402 M4
1.2m Triax dish
Technomate H to H motor
My Location
Ireland
What happened with the power supply replacement. Did it not work out. Was the new MB expensive. Could you isolate the problem on the old MB.
 
Terryl

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,300
Reaction score
1,944
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
Satspot said:
What happened with the power supply replacement. Did it not work out. Was the new MB expensive. Could you isolate the problem on the old MB.
Click to expand...
Replacing the power supply had the same problem, after several talks with the CS tech we found that the voltage comparator circuit for the +12 voltage to the CPU was not working correctly, this circuit looks at the power to the CPU, if too low it will not let the PC post.

It's supposed to look at the on board regulated DC output for +12 and other voltages to the CPU if too low (it was +9.1 volts) it stops the CPU BIOS from posting.

DC power input from the power supply was as follows, +12.8 volts, +5.3 V and -5 V, after the onboard DC regulators it was +12V, +5V, +3, 1.2V (for the RAM) and -5, measured at the CPU input the +12 was only +9.1 volts, removing or replacing a RAM stick caused the comparator circuit to re-evaluate the voltages, think it's OK and let the system boot, that is until you powered it down, then that circuit said that the +12 voltage was too low and stopped the booting processes.

Normal motherboards do not use this type of setup as the standard PC power supply has the DC voltages needed to run the computer, this PC power supply only supplys +12 +5 and -5, the rest are done on the motherboard.
 
Last edited:
Top