Viewsonic 20" VG2030wm

[Aruba]

Found this LCD monitor in the hallway at work with a post-it note that
says "Dead". Took it into the lab and attached AC power and only the blue
light came on on the on/off button and nothing else. Opened it up and found
no visible bulging caps but did find two popped FET ICs. These should be the
inverter driver FETs with part# STM8306 printed on them. There are a total
of four of these ICs and only two are visibly damaged. The other undamaged
two although measuring ok may have seen adverse effects that probably
needs to be replaced as well. These STM8306 dual FETs with one being a
N-channel FET and the second being a P-channel FET seems to come from a
company called SamHop based in Taiwan. I looked around and can't find any
US sources for these STM8306. Does anyone know where I can find these or
recommend an applicable substitution ? My research shows the Vishay
Si4599 part should work in this application.
Pictures of the popped FET packages and the spec for the STM8306 and Si4599DY are attached. Any help is appreciated.

Aruba

[jetadm123]

Re: Viewsonic 20" VG2030wm

Apparently, viewsonic used several different duo mosfets for Q901-904:

STM8306
AM4502C
AP4509GM
AP4511GM

Replace them in pairs.

[jetadm123]

Re: Viewsonic 20" VG2030wm

Oh, I forgot to add that since you got the monitor for free, it probably wouldn't hurt to replace all caps, except for the large 450V one. It might have been a failing cap that caused the mosfet failure.

[Scenic]

Re: Viewsonic 20" VG2030wm

all caps look like they're HERMEI (with a panasonic T-vent )
definitely replace them. known crapcap brand

[Aruba]

Re: Viewsonic 20" VG2030wm

Apparently, viewsonic used several different duo mosfets for Q901-904:

STM8306
AM4502C
AP4509GM
AP4511GM

Replace them in pairs.

Thank you for the different part numbers. I checked with my usual sources and
none of them carry these parts. Do you know of a source where I can order
these parts ? All the electrolytic caps on the power supply are indeed HERMEI.
I will make sure to replace all of them before I power this unit back on.

Wah

[retiredcaps]

Re: Viewsonic 20" VG2030wm

Do you know of a source where I can order
these parts ?

Send a PM to leperinc. He just bought 10 of AF4502C off ebay and lives in Ottawa. See this thread

https://www.badcaps.net/forum/showthread.php?t=12959

See the last thread about his fixed monitor and tell him he can "thank" me by sending a couple of those chips your way.

[jetadm123]

Re: Viewsonic 20" VG2030wm

In addiition to retiredcaps suggestion, the AP4511GM is readily available on ebay.

[Aruba]

Re: Viewsonic 20" VG2030wm

In addiition to retiredcaps suggestion, the AP4511GM is readily available on ebay.

Thanks for the suggestion. I will check it out. I have already ordered
similar Vishay parts. Hopefully they will be arriving next week and I will give
an update when I have these FETs and the new caps installed.

Aruba