| Electronics > Repair |
| Mainboard with No Picture |
| (1/8) > >> |
| 2X:
Hi, I have the motherboard W26361-W84-X-02 where it starts the CPU fan but don't show nothing at all. The problem as I saw is that the CPU don’t take a proper voltage. I measured with oscilloscope the voltages on three CPU inductors and the voltage was mVolt and the processor was a bit warm (not hot like a CPU is). I measured the pulses from the 15,18,19 pins of ISL6565BCRZ (Multi-Phase PWM Controller) and looks OK. Also, these pulses arrive at the pin 3 of each ISL6612ECB-T (Advanced Synchronous Rectified Buck MOSFET Driver) respectively. The problem in my opinion is at the output pin 1 that drives the high side mosfet. And in three chips ISL6612ECB-T the pulses are weak and seems like a noise. I checked for shorts but I didn't find anything and I replace the electrolytic caps. Also, I tried the below: I replaced the RAM with a same and functional one (from a same second motherboard that I have). I replaced the CPU with a same and functional one (from a same second motherboard that I have). I check the CPU socket for bend pins and all are ok. I have replace the BIOS chip with a same and functional one (from a same second motherboard that I have). I have replaced all the caps in the yellow circles with brand new capacitors. I place a buzzer on the motherboard and no beep even when I remove the RAM. I tried some PCI tester cards and gave me the below codes: The one of them show nothing "--". The second show "0000". The third show "FF". As I saw in a "PC Analyzer Users Guide" pdf that I found on the internet: The "00" means "Code copyng to specific areas is done. Passing control to INT 19h boot loader next. The "FF" means "Flash ROM programming was succesful. Next restarting the system BIOS." Do you know what these codes means in practical level? Datasheets: https://www.renesas.com/us/en/document/dst/isl6612-isl6613-datasheet (ISL6612, ISL6613) https://www.mouser.com/datasheet/2/698/intersil_fn9135-1277737.pdf (ISL6565A, ISL6565B) https://dimm.me/wp-content/uploads/PC_Analyser_Instructions_PCI_ESA_Card_FINAL_OCR-libre.pdf P.S. I can’t through the motherboard in the bin because it is from an old machine and unfortunately works only with this motherboard with any other similar |
| indeterminate:
Connect a speaker to the board if there is any life in the board you should be able to hear sum beep codes if no beep codes then look up the voltage requirements for the cpu and use a meter to find out witch supply is faulty. |
| coromonadalix:
ok you have posted elsewhwere too i think and this board is a Fujitsu Siemens FSC D1837-A21 W26361-W84-X-02 ATX Mainboard Sockel/Socket LGA775 Intel 915 chipset, you should be able to substitue it, unless you have very specialized software and or markers who will block from working you may have gone too far changing all the capacitors.. normally you do the ones in the cpu power section, theses fails often what caps have you put in there, low esr ones ? standard ones, high temps ... and the correct orientation ? have you tried the psu and forced the psu to start, you have many infos on how to and atx pinouts ... voltage on the 4 pins cpu power plug, and voltages on the main plug ? https://theretroweb.com/motherboards/s/fujitsu-siemens-d1837 |
| 2X:
--- Quote from: coromonadalix on July 14, 2024, 10:42:41 am ---ok you have posted elsewhwere too i think and this board is a Fujitsu Siemens FSC D1837-A21 W26361-W84-X-02 ATX Mainboard Sockel/Socket LGA775 Intel 915 chipset, you should be able to substitue it, unless you have very specialized software and or markers who will block from working you may have gone too far changing all the capacitors.. normally you do the ones in the cpu power section, theses fails often what caps have you put in there, low esr ones ? standard ones, high temps ... and the correct orientation ? have you tried the psu and forced the psu to start, you have many infos on how to and atx pinouts ... voltage on the 4 pins cpu power plug, and voltages on the main plug ? https://theretroweb.com/motherboards/s/fujitsu-siemens-d1837 --- End quote --- --- Quote ---you should be able to substitue it, unless you have very specialized software and or markers who will block from working --- End quote --- unfortunately I can't replace it because have very specialized software. --- Quote ---what caps have you put in there, low esr ones ? standard ones, high temps ... and the correct orientation ? --- End quote --- I placed new nichicon and panasonic Low ESR capacitors and I placed them with the right orientation/polarity. --- Quote ---have you tried the psu and forced the psu to start, you have many infos on how to and atx pinouts ? --- End quote --- Sorry but I don't now what do you mean with the "tried the psu and forced the psu to start" This that I did is to jumper the pins "Power ON-OFF" instantaneously and the PSU start ok (I also tried another PSU) and the voltage on the 4 pins cpu power plug is 12V and on ATX connector there is the voltages 3.3V, 5V & 12V and the pins that they should be (I will check a them again and I will post them). Thanks for your time and your detailed reply. |
| coromonadalix:
atx psu's can be forced to start you need to tie a wire to ground, check on the web atx pinouts, normally it's the green wire if i recall. and to help regulations sometimes, i put a defective hdd just to create some current draw clear the motherbaord cmos, sometimes it can help, as other wrote, if you dont get beeps post codes, the trouble may be harder than you think, the cpu section could be dead ... and sadly the motherboard is toasted the post codes are not fully universal, you need the ones for you bios brand phoenix, award etc .... as for specialized software what it is ? pick and place .. security ... usb dongle keys, hardware id's, you can at least say something .. unless from the start something is fishy ... you should try to find intel 915G based chipsets motherboards .... some are very cheap and you talk about a second motherboard does it suffer the same problems ? |
| Navigation |
| Message Index |
| Next page |