HannsG HW173D dead. Recap = new fault.

[jetadm123]

Re: HannsG HW173D dead. Recap = new fault.

Whai is the part number of device circled in yellow?

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

My guess would be the single heatsinked device U101. It's probably a combined pwm/fet. What's the part number of U101?

Do you mean U301?
MPS 0633
MPI008ES
649455 19

[Rtech]

Re: HannsG HW173D dead. Recap = new fault.

Hmm, U302 wasn't what I thought it would be (a PWM). This makes sense given the location of U302 (in the inverter section).

Usually on these types of boards, there is a 8 pin IC which is a pulse width modulator. I can't see one anywhere in the power section of the board?

The PWM may well,be incorporated in the IC that is immediately below the Main Tfmr on the single heatsink, I cannot tell from the bottom actually how many pins it has ?? and the part number off that may supply the answer.

[jetadm123]

Re: HannsG HW173D dead. Recap = new fault.

Hmm, U302 wasn't what I thought it would be (a PWM). This makes sense given the location of U302 (in the inverter section).

Usually on these types of boards, there is a 8 pin IC which is a pulse width modulator. I can't see one anywhere in the power section of the board?

My guess would be the single heatsinked device U101. It's probably a combined pwm/fet. What's the part number of U101?

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

U302 is SP8K3 635.

Hmm, U302 wasn't what I thought it would be (a PWM). This makes sense given the location of U302 (in the inverter section).

Usually on these types of boards, there is a 8 pin IC which is a pulse width modulator. I can't see one anywhere in the power section of the board?

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

If replacing the little cap doesn't solve the problem, the next step is to check U302. While you are replacing caps, you might as well replace the rest of the original power board caps with something like Panasonic FR, FM or FC caps.

What is the part number of U302 (the 8 pin chip) on the back of the power board?

U302 is SP8K3 635.

All the caps had been replaced except C123. It had been replaced with a used one because I did not have a new one at the time. The new cap is doing the same as the old one.

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

5v - 11v

If replacing the little cap doesn't solve the problem, the next step is to check U302. While you are replacing caps, you might as well replace the rest of the original power board caps with something like Panasonic FR, FM or FC caps.

What is the part number of U302 (the 8 pin chip) on the back of the power board?

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

okay, c114 is good for now.

C123 plays an important part of the startup smps process. These little caps can often fail but without visible bloating.

This is why forum members here recommend replacing all capacitors when you find bad ones on the power board. So replace the little cap and retest.

Ps. What is the fluctating voltage on c123?

5v - 11v

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

1) C114 is 160V

2) C123 is fluctuating

Okay, C114 is good for now.

C123 plays an important part of the startup SMPS process. These little caps can often fail but without visible bloating.

This is why forum members here recommend replacing ALL capacitors when you find bad ones on the power board. So replace the little cap and retest.

PS. What is the fluctating voltage on C123?

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

1) Carefully measure the DC voltage across the largest capacitor (C114). It should be mains x 1.414. If you have 120V AC, then you should get 120 x 1.414 = roughly 165V DC.

Careful, this is high voltage. Put your multimeter on 200V DC. Put your black probe on the negative leg of the capacitor and red probe on the positive leg.

2) Now put your multimeter on 20V DC and measure voltage across the capacitor C123. Note if the voltage is steady of fluctuating.

1) C114 is 160V

2) C123 is fluctuating

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

1) Carefully measure the DC voltage across the largest capacitor (C114). It should be mains x 1.414. If you have 120V AC, then you should get 120 x 1.414 = roughly 165V DC.

Careful, this is high voltage. Put your multimeter on 200V DC. Put your black probe on the negative leg of the capacitor and red probe on the positive leg.

2) Now put your multimeter on 20V DC and measure voltage across the capacitor C123. Note if the voltage is steady of fluctuating.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I went back and reread your first post. You never did explain what is wrong with your monitor other than just replacing the Capxon caps.

No power light.

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

Thank you so much for working with me.

I went back and reread your first post. You never did explain what is wrong with your monitor other than just replacing the Capxon caps.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

Do not use the continuity or "beep" feature of your multimeter for measurements. Some multimeters "beep good" for resistance readings less than 1.5k ohms.

Always post the actual results of your measurements when asking for help.

A good fuse should measure less than 1.0 ohms.

Both fuses I checked, meter set at 2k, reads .000. It was check while installed in the board. So these fuses are good.

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

I did check the continuity on both fuses and they check out.

Do not use the continuity or "beep" feature of your multimeter for measurements. Some multimeters "beep good" for resistance readings less than 1.5k ohms.

Always post the actual results of your measurements when asking for help.

A good fuse should measure less than 1.0 ohms.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

On the solder side of the Board, put the -ve lead 0f your meter, to the -ve side of ANY of the 4 capacitors beside the heatsink(the -ve side is the one with the stripe running down the cap),and then the +ve lead of your meter to the centre pins of the two diode on the Heatsink,meter on DC Volts, range 20 or 100 volts,and what do you get ??

0.0 on both. Thank you so much for working with me. I know it must be frustrating dealing with people new to this field. I have alway been interested in electronics, but never had the time....thx again.

[Rtech]

Re: HannsG HW173D dead. Recap = new fault.

On the solder side of the Board, put the -ve lead 0f your meter, to the -ve side of ANY of the 4 capacitors beside the heatsink(the -ve side is the one with the stripe running down the cap),and then the +ve lead of your meter to the centre pins of the two diode on the Heatsink,meter on DC Volts, range 20 or 100 volts,and what do you get ??

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I can't see the silkscreen on your photos for D240 and D260. On your third photo, they are the only two devices mounted on the same heatsink above the yellow transformer. You mentioned you read 5V on the connector on one of your previous posts. Well, that 5V should coming from one of those two diodes. Is your meter set to DC volts? Try the 20V setting. Place your ground probe on a mounting screw and place your red probe on the middle leg to measure output voltage.

I have the boards out of the monitor and using the ground from the power cord on the solder side. Doing this I get nothing. If I find another ground on the board, the reading on the one diode goes up and down. The other one is zero.

[jetadm123]

Re: HannsG HW173D dead. Recap = new fault.

Are the diode's D240 & D260 and are we talking about 5DCV and 12 DCV? If so then I am getting a reading of 0V. Am I corrected by using the ground from the power cord?

I just tried to use a different ground and got one diode to bounce between .4V and .6V and 0 on the 12V diode. When the voltage changes from AC to DC, does the ground change?

I can't see the silkscreen on your photos for D240 and D260. On your third photo, they are the only two devices mounted on the same heatsink above the yellow transformer. You mentioned you read 5V on the connector on one of your previous posts. Well, that 5V should coming from one of those two diodes. Is your meter set to DC volts? Try the 20V setting. Place your ground probe on a mounting screw and place your red probe on the middle leg to measure output voltage.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

You have two diode packs mounted on the same heatsink. One diode should output 5V and the other 12V. Measure the middle leg of each diode for these voltages. Like alexanna suggested, we need some good focused photos of YOUR boards. Referencing someone else's board photos hinders the troubleshooting process.

Are the diode's D240 & D260 and are we talking about 5DCV and 12 DCV? If so then I am getting a reading of 0V. Am I corrected by using the ground from the power cord?

I just tried to use a different ground and got one diode to bounce between .4V and .6V and 0 on the 12V diode. When the voltage changes from AC to DC, does the ground change?