Hi All,
I'm new in BadCaps, so I hope this is the right forum to make my question.
I come here because I have an IBM NetVista 6790 that doesn't boot.
I have always liked to tinker with PCs but only recently started trying to get into component repair, so I know how to check a PC but I'm at a loss without schematics on what to check when things are not obvious (i.e. a shorted mosfet). Also, I am sure there are a lot of symptoms that for someone experienced will point directly to the issue, but I don't know how to identify.
So this machine doesn't boot, and by that I mean:
- When using the power button, it starts the CPU fan
- It can be shut down with the button after 6 seconds
- the CPU doesn't get hot (which is quite an achievement for a P4...)
- RAM voltage looks OK (3.3 V)
There are no ICs getting hot, nor any kind of damage in traces or components. The capacitors *look* ok, none of them is obviously damaged.
I changed the battery in case that would be part of the problem. I also checked the power mosfets with my multimeter.
- for three out of four CPUS I have, I got a correct reading (1.8 V)
- for the other, a P4, I got 1.4 V
I actually kept checking and noticed the voltage in the mosfets was not stable: instead it took like a minute after the board was turned on to get to those values (slowly increasing from around 1V). Does that mean anything?
In summary, what I would like to ask is: what else can I check now?
I'm absolutely aware that this repair doesn't make sense from an economics point of view, but it's a learning experience and also I love the IBM-iness of this machine so I'd really enjoy having it running again.
Thanks in advance
I'm new in BadCaps, so I hope this is the right forum to make my question.
I come here because I have an IBM NetVista 6790 that doesn't boot.
I have always liked to tinker with PCs but only recently started trying to get into component repair, so I know how to check a PC but I'm at a loss without schematics on what to check when things are not obvious (i.e. a shorted mosfet). Also, I am sure there are a lot of symptoms that for someone experienced will point directly to the issue, but I don't know how to identify.
So this machine doesn't boot, and by that I mean:
- When using the power button, it starts the CPU fan
- It can be shut down with the button after 6 seconds
- the CPU doesn't get hot (which is quite an achievement for a P4...)
- RAM voltage looks OK (3.3 V)
There are no ICs getting hot, nor any kind of damage in traces or components. The capacitors *look* ok, none of them is obviously damaged.
I changed the battery in case that would be part of the problem. I also checked the power mosfets with my multimeter.
- for three out of four CPUS I have, I got a correct reading (1.8 V)
- for the other, a P4, I got 1.4 V
I actually kept checking and noticed the voltage in the mosfets was not stable: instead it took like a minute after the board was turned on to get to those values (slowly increasing from around 1V). Does that mean anything?
In summary, what I would like to ask is: what else can I check now?
I'm absolutely aware that this repair doesn't make sense from an economics point of view, but it's a learning experience and also I love the IBM-iness of this machine so I'd really enjoy having it running again.
Thanks in advance
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