Apologies if I am off topic
This mobo is completely dead - rec'd this way.
As mobo soft-start does not even does not initiate, I suspect
+12v line dead. PSU known good, RAM known good, CPU known
good.
This mobo uses an Intersil ISL6556CBC PWM IC and is appears to
be based on the Intel VRM/VRD 10.x specification. Further uses dual (HIP6602CBC) and single (HIP6601CBC) MOSFET drivers. VR on board must be a three-phase design (9 MOSFETs) as well as there being three drivers available.
As the PWM IC is underneath the s428 HSF package, I cannot
get a multi meter reading with CPU and HSF in situ but can access
the MOSFET driver ICs on mobo surface.
A physical inspection of the board finds 2 of RS-232 serial TX/RX
ICs having, in part, a shiny surface - is this ok? These work
with +12V.
I find there are no open grounds on the ATX power connector with
PSU disconnected.
I find both the MOSFET drivers ICs are not getting any drive or supply voltage and hence consider as soft-start does not operate, that is, the
PWRON jumper on the front panel jumper block does not work,
the Intersil ISL6556CBC PWM IC is faulty - to be replaced.
Any advice, insight and opinions appreciated.
Trigem TG-865PE (MSI 865PEM2 [MS-6743 v1.1)] - Advent 3117
Was formerly used with a Bestec ATX-250-12E Rev F1, these have
no overvoltage protection. Have tried to start with known good PSU which does not have an on/off switch
Symptom - PS-ON will not go low.
The mobo front panel header for Power on will not start mobo.
Took reading with mmeter across the two pins, only drops to 4.88V
Shorted pins 13,14 on ATX (2 x10) connector - can get the PSU,
in turn, mobo to start but the southbridge is getting very hot. Albeit I shut
the system down from the wall outlet before the s/bridge gets
totally fried, the mobo did appear to POST.
Next, using freezer spray, cooled down the s/bridge for sufficient
time to observe mobo behaviour. Only had diskette drive attached
with Memtest86 v3.3 utility - this all goes smoothly and will load
the utility from diskette into memory and starts testing memory.
I have tested the mobo to the extent, tested ATX (2x10) connector
for ground fault on pins 3,5,7,13,15,16 and 17 all ok
The Intel part FW82801EB SL73Z - is it known to have a thermal problem?
Is the board exhibiting problem consistent with over voltage problem per
Bestec failires?
Any insight, help, advice and guidance appreaciated
no overvoltage protection. Have tried to start with known good PSU which does not have an on/off switch
Symptom - PS-ON will not go low.
The mobo front panel header for Power on will not start mobo.
Took reading with mmeter across the two pins, only drops to 4.88V
Shorted pins 13,14 on ATX (2 x10) connector - can get the PSU,
in turn, mobo to start but the southbridge is getting very hot. Albeit I shut
the system down from the wall outlet before the s/bridge gets
totally fried, the mobo did appear to POST.
Next, using freezer spray, cooled down the s/bridge for sufficient
time to observe mobo behaviour. Only had diskette drive attached
with Memtest86 v3.3 utility - this all goes smoothly and will load
the utility from diskette into memory and starts testing memory.
I have tested the mobo to the extent, tested ATX (2x10) connector
for ground fault on pins 3,5,7,13,15,16 and 17 all ok
The Intel part FW82801EB SL73Z - is it known to have a thermal problem?
Is the board exhibiting problem consistent with over voltage problem per
Bestec failires?
Any insight, help, advice and guidance appreaciated