Hi there.
First of all thanks for having me. I’ve posted in the introduce yourself section a little bit about myself.
I have recently purchased two faulty motherboards for a fruit machine that i have, these PC’s are getting very hard to find now with them getting older, so seeing as ive had a bit of experience with repairing Nintendo DS’s i thought id try my hand at PC repair too.
The first motherboard(ive not looked at the second one in any detail yet) has an issue which it will start up, the CPU fans spin but it does not post to BIOS, I get a slight crackle sound from the on board speaker but nothing happens, it will just sit in a undefined state until turned off again.
Things i have done
Tested the power supply.
Reflashed the BIOS with a CH341A by taking the bios out of my working fruit machine and copying the data off the chip.
checked for voltages on the board, all seem ok from what i can tell.
inserted a PCI analyser into the motherboard, now this is where i found an issue, the reset light stays on all the time, so I’m guessing the CPU is stuck in a permanent reset state.
now my question is what could cause this issue and where would i look to find it, ive watched various videos on YouTube trying to find the issue, and some videos do actually capture the problem, my problem is i have no schematics for the board and I don’t really know where to look for the circuits.
another issue i have found appears to be the BIOS chip (STS25VF0808) has voltage on most of the pins as follows
PIN 1 CE# 3.3V
PIN2 SO 3.3 V
PIN3 WPH 3.3V
PIN 4 VSS Ground
PIN 5 SI 0V
PIN 6 SCK 0V
PIN7 HOLD# 3.2V
PIN 8 VDD 3.2V
Ihave attached a photo of the Board.
Any help would be greatly appreciated.
Glenn
First of all thanks for having me. I’ve posted in the introduce yourself section a little bit about myself.
I have recently purchased two faulty motherboards for a fruit machine that i have, these PC’s are getting very hard to find now with them getting older, so seeing as ive had a bit of experience with repairing Nintendo DS’s i thought id try my hand at PC repair too.
The first motherboard(ive not looked at the second one in any detail yet) has an issue which it will start up, the CPU fans spin but it does not post to BIOS, I get a slight crackle sound from the on board speaker but nothing happens, it will just sit in a undefined state until turned off again.
Things i have done
Tested the power supply.
Reflashed the BIOS with a CH341A by taking the bios out of my working fruit machine and copying the data off the chip.
checked for voltages on the board, all seem ok from what i can tell.
inserted a PCI analyser into the motherboard, now this is where i found an issue, the reset light stays on all the time, so I’m guessing the CPU is stuck in a permanent reset state.
now my question is what could cause this issue and where would i look to find it, ive watched various videos on YouTube trying to find the issue, and some videos do actually capture the problem, my problem is i have no schematics for the board and I don’t really know where to look for the circuits.
another issue i have found appears to be the BIOS chip (STS25VF0808) has voltage on most of the pins as follows
PIN 1 CE# 3.3V
PIN2 SO 3.3 V
PIN3 WPH 3.3V
PIN 4 VSS Ground
PIN 5 SI 0V
PIN 6 SCK 0V
PIN7 HOLD# 3.2V
PIN 8 VDD 3.2V
Ihave attached a photo of the Board.
Any help would be greatly appreciated.
Glenn
