Hitachi 40HXC06U problems

[budm]

Re: Hitachi 40HXC06U problems

So he replaced the IC and the resistor but not the MOSFET, more likely then that his new IC is now damaged too due to the shorted out original MOSFET.

[ReeceyBurger123]

Re: Hitachi 40HXC06U problems

Probably.

[StephenU]

Re: Hitachi 40HXC06U problems

BTW, MOSFET Q204 is fine not shorted between Source and Drain?
C205 is the one that blew?

So he replaced the IC and the resistor but not the MOSFET, more likely then that his new IC is now damaged too due to the shorted out original MOSFET.

Probably.

Here goes :

Replaced damaged IC201 (Original part) and R272 (0.47 wirewound sourced from ebay 3W but 1W as stated in the schematics) ~ ~ BudM will this 3W / 1W difference be ok ?? ~ ~

Power on BOOOM F100 toast.

Went straight to the mosfet Q204 thats was toast and gone, complete short.(Yeh yeh I know school boy error. my bad..AArrrggg )

also took out D104-D107 all shorted

***********

So now ordered:

F100 fuses - (in hand)
Q204 Mosfet (On order)
D104-D107 (On order)

IC201 looks visually fine but will try a reverse diode to ground check on all pins. or might just order a new one to be on the safe side.


Anything else I should check guys.

Let me know what you think, and thanks for the help.


Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

I would also replace the SG6742HR ic201 just too be on the safe side.

[StephenU]

Re: Hitachi 40HXC06U problems

I'm trying to source an alternative to the one Mosfet Q204 fitted, the markings on the one that came out the board are MDF4N60 (Datasheet > http://www.datasheet-pdf.com/PDF/MDF...gnaChip-898610)

original on schematic says FQPFN50C (http://uk.rs-online.com/web/c/semico...50464E35304326) But this is discontinued.


Thanks

Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

sorry ignore the link i found is disscountinued too

[vinceroger69]

Re: Hitachi 40HXC06U problems

This is the nearest i can find too the original specs
http://uk.rs-online.com/web/p/mosfet...33393438383526

[StephenU]

Re: Hitachi 40HXC06U problems

This is the nearest i can find too the original specs
http://uk.rs-online.com/web/p/mosfet...33393438383526

went for it, thanks.


Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

I have a rs account so went on live chat and thats what they recomended as a replacement so if wrong we will can blame them.

[budm]

Re: Hitachi 40HXC06U problems

BTW, that IC201, if the internal drive output is shorted to GND then the POWER MOSFET will not be damaged, the circuit just will not be working, but if the internal drive is shorted to the VCC (when the shorted MOSFET dumped the 300 something Volt into the Gate drive pin of the IC) which will make the output to be HIGH with steady Voltage at the output instead of high speed switching then the POWER MOSFET will blow, so I would change the IC and check all the Gate drive R/D network for damages.

[ReeceyBurger123]

Re: Hitachi 40HXC06U problems

BTW, that IC201, if the internal drive output is shorted to GND then the POWER MOSFET will not be damaged, the circuit just will not be working, but if the internal drive is shorted to the VCC (when the shorted MOSFET dumped the 300 something Volt into the Gate drive pin of the IC) which will make the output to be HIGH with steady Voltage at the output instead of high speed switching then the POWER MOSFET will blow, so I would change the IC and check all the Gate drive R/D network for damages.

+1 check the 1uf 50v MLCC next to the controller this causes this which blows shit up ! Also if the fet fails it blows the bridge diodes too.

[StephenU]

Re: Hitachi 40HXC06U problems

UPDATE:

All new parts fitted >

F100 fuses
Q204 Mosfet
D104-D107
IC201

All seems good with the psu now but still no standby light activity, I suspect the mainboard is the issue as I had an old one (different version) and tried that and and have standby light activity, it tries to come on but, nothing, i'm sure this part is out of an old set that had corrupt flash, thats whats giving me the indication of mainbaord, i have a few of these mainboards that are faulty are they anyway of fixing them like reflashing etc or just good for parts.

Thanks in advance to all.


Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

whats the original mainboard part number?

[StephenU]

Re: Hitachi 40HXC06U problems

whats the original mainboard part number?

17MB82 - 1a

23110916

Thanks.

[vinceroger69]

Re: Hitachi 40HXC06U problems

yes i thought it might be as just been reading a few threads which reece has posted in time too look for a replacement main board i guess now.

not sure if your board has failed complety as no led light on the tv reece has a video on a update for them but thats with a flashing led yours does not have this.
https://www.youtube.com/watch?v=kPCisa9BYkk

[ReeceyBurger123]

Re: Hitachi 40HXC06U problems

Update ?

[dick_barton]

Re: Hitachi 40HXC06U problems

I have a rs account so went on live chat and thats what they recomended as a replacement so if wrong we will can blame them.

Hi vincerogers69
cpc.co.uk
http://uk.farnell.com

are also good UK suppliers who are happy to take your money if you don't already use them.