Help Identify Capacitor

[Gladiatorx]

Re: Help Identify Capacitor

No i didn't have the main board connected. Figured if the fuse held longer than a split second I could power off then connect the main board. But the fuse just blew too fast.

at + & - of bridge i get.4 ohm

[Gladiatorx]

Re: Help Identify Capacitor

Also since it blew so fast there was no 13V

[R_J]

Re: Help Identify Capacitor

.4 Ω is basically a short so something is sorted after the bridge
Check diodes dp802,dp803,dp808c, fets, QP801CS, QP811CS, QM801CS,QM802CS
You can check the resistance across CP811s/812s, If it checks shorted, Unsolder the 2 jumper wires J829 & J830, then check the resistance across cp811s and then across CP812s, this will isolate where the short is.

[Gladiatorx]

Re: Help Identify Capacitor

dp802 - .552V and OL the other way

dp803 - .555V and OL the other way

QP801CS - between source and drain it beeps; between gate and source 324 ohms

QP811CS - between source and drain it beeps; between gate and source 133 ohms

QM801CS - neg lead on D & + lead on S = 494 ohms; + lead on D & pos lead on S = OL

QM802CS - neg lead on D & + lead on S = 493 ohms; + lead on D & pos lead on S = OL

CP811 - in circuit shows 128 mico farad that's with my meter set to read capacitance

With meter in resistance mode it starts at 143k ohms and then rises up

CP812 - in circuit shows 128 mico farad that's with my meter set to read capacitance

With meter in resistance mode it starts at 143k ohms and then rises up same as CP811

[R_J]

Re: Help Identify Capacitor

well if those are the readings, then it must be the bridge rectifier that is shorted

at + & - of bridge i get.4 ohm

[Gladiatorx]

Re: Help Identify Capacitor

Removed the Bridge rectified off the board, tested good

[R_J]

Re: Help Identify Capacitor

Then where are you getting the .4 ohm reading when checking across + & - ? If you are reading .4 ohms across + & - of the bridge, remove CP801S & CP802S If they are ok, and the short is still across +&-, check CP811, (another small blue cap)
Or DP808c (you did not report resistance) or the capacitor you installed is shorted??

[sam_sam_sam]

Re: Help Identify Capacitor

Removed the Bridge rectified off the board, tested good

Have you checked the two items that are near “J828” that are on a heat sink what are they part number

[budm]

Re: Help Identify Capacitor

QP801CS - between source and drain it beeps; between gate and source 324 ohms

QP811CS - between source and drain it beeps; between gate and source 133 ohms

So what are the resistance between Source and Drain for those two PFC MOSFET's? It sounds like the PFC MOSFET's are shorted out or the snubber caps for them are shorted out since they are connected in pareallel.

[R_J]

Re: Help Identify Capacitor

this is the problem when people say the meter beeps and not give an actual resistance reading. could be shorted fets.

[budm]

Re: Help Identify Capacitor

this is the problem when people say the meter beeps and not give an actual resistance reading. could be shorted fets.

+10, I do not know why people use beep mode to look for shorted device/circuit, most meter will beep with resistance as high as 50 Ohms.

[R_J]

Re: Help Identify Capacitor

I just checked one of my meters on a 120Ω resistor and it beeps.

[Gladiatorx]

Re: Help Identify Capacitor

R_J - Yes resistance on rectifier was in circuit and between + & - is was .4

CP801S with meter is resistance mode - i get 3 ohms

CP802S with meter is resistance mode - i get 3 ohms

CP801S with meter is capacitor mode - I get a split sec 0 micro farads then OL

CP802S with meter is capacitor mode - I get a split sec 0 micro farads then OL

DP808C - starts at 72k ohms and just climbs kept climbing past 100K ohms if I read it again it starts at say 140K & just climbs

CP813 (the one that was blown and I replaced - in capacitor mode in one direction +/- meter leads I get 426 micro farads, in the other direction +/- meter leads I get 128 micro farads

CP813 with meter in ohms - starts at 72k ohms and just climbs kept climbing past 100K ohms if I read it again it starts at say 140K & just climbs

sam_sam_sam - the components are QM801cs they say they are 1E03AU FDPF 8N50NZ on the board the seemed to test ok

BUDM - QP801CS & QP811CS maybe I tested these wrong the first time. But here is what I got this time with meter in resistance mode I left the bridge rectifier off the board

QP801CS - between S & D diode mode = beep; between G & S 334 ohms

QP801CS - between S & D resistance = .1 ohms; between G & S still 334 ohms

QP811CS - between S & D = diode mode = beep; between G & S 144 ohms

QP811CS - between S & D resistance = .1 ohms; between G & S still 144 ohms

[sam_sam_sam]

Re: Help Identify Capacitor

QP801CS - between S & D diode mode = beep; between G & S 334 ohms

QP801CS - between S & D resistance = .1 ohms; between G & S still 334 ohms

QP811CS - between S & D = diode mode = beep; between G & S 144 ohms

QP811CS - between S & D resistance = .1 ohms; between G & S still 144 ohms

If this is the results you got then you have a problem with this device between the S & D looks it is shorted ( does it matter which way you have the test leads in diode test mode do get the same results )

Take them out of your board and see if you still read the short that was on the bridge rectifier + and - if still does then still have more work to do to find what else is still shorted

This is the part number 8N50NZ

[Gladiatorx]

Re: Help Identify Capacitor

QP801CS & QP811CS are both part no. 13NM60N

QM801cs which seemed to test fine in circuit is part no. 8N50NZ

Also, what's that white stuff on the ternimals? Feels like white silicone, can do I have to replace that after?

[budm]

Re: Help Identify Capacitor

At this point, the Gate Drive output of the PFC IC may be damaged when the MOSFET's shorted out so when you put in new MOSFET's they may get damaged, I would suggest to replace IC at the same time or take the chance of blowing up new MOSFET's.

[Gladiatorx]

Re: Help Identify Capacitor

bubm - can you tell me the number on the board of that IC so i can locate it

The IC i read is ICP801 and it says S3051 but I can't find any data sheet on it.

Also can this be tested at all? That's a bit too small for me to remove and replace

[Gladiatorx]

Re: Help Identify Capacitor

pulled out QP811CS between drain and source meter beeps while in diode mode

[R_J]

Re: Help Identify Capacitor

LOOSE THE BEEP, that is useless and does'nt mean anything. use the ohm setting or diode test and post the resistance number.

QP801CS & QP811CS are shorted drain to source
White stuff is silicone heatsink compound and should be used on the replacement parts.

[Gladiatorx]

Re: Help Identify Capacitor

Oh I thought in diode mode when you get a beep it means it's open and only get 0 Vdc on the meter

Meter in Diode mode:
QP811CS -- D to S = 0.00 vdc; G to S = .14Vdc


Meter in Diode mode:
QP801CS -- D to S = OL vdc; G to S = OL Vdc

When I touched the gate on QP801CS then I got it to turn on and meter showed 0.00 vdc
------------------------------

Meter in resistance mode:
QP811CS -- D to S = 0.1 ohms; G to S = 149.8 ohms; G to D = 149.8 ohms
Meter Leads reversed -- D to S = 138.3 ohms; G to S = 149.8 ohms; G to D = 138.3 ohms

Meter in Resistance mode:
QP801CS -- D to S = .4M ohms; G to S = OL ohms; G to D = OL ohms
Meter Leads reversed -- D to S = .4 ohms; G to S = OL ohms; G to D = OL ohms