Sanyo DP32642 No Power

[killian6pk]

Re: Sanyo DP32642 No Power

Thanks tom will get the other fet checked out and also the smd components.

[tom66]

Re: Sanyo DP32642 No Power

Power board schematic may be available in one of these
http://www.tgohome.com/ServiceManual...&Search=Submit

[killian6pk]

Re: Sanyo DP32642 No Power

Thanks for the service manual link. I will read through it and see if anything jumps out at me.

You were correct about the second of the two fets being bad. I have replaced both of them. On the back side of the board there are 3 resistors and one diode per fet. Check these reading for me to see if these components need to be replaced.

Fet q15 – R132 R130 R129 D14
47.2ohms 22.1 46.9 69.1ohm

Diode Setting .058v
.058v probes rev.

Fet q16- R138 R134 R137 D15
47.2 ohms 46.7 22.1 68.7ohms

Diode Setting .058v
.057v
Is there some way to format data so that it will stay formated after you type it in? Tried typeing into word proc. and formating goes away when I copy it over to Bad Caps.
Thanks

[tom66]

Re: Sanyo DP32642 No Power

Do any of those files have the correct schematic for your board? Use that for values to check against.

[killian6pk]

Re: Sanyo DP32642 No Power

Ok I am having a really big problem. The Service Manual DP32642-00 seems to be the correct manual. The problem is that I can't read the writing on the Page that has the Power board pictured. If I increase the size on the monitor the writing blurs out. I tried printing the page and tried to look at it under magnification and it looks like it was printed on a dot matrix printer and there is no way to read it either. The diodes do not have any writing on them. The resistors have lettering that I think I have figured out. Is there any other way of determining the values of the diodes?

There is a list of components but none of the locations match what are on my board. My board says R132 and on the list there is no R132. In fact I can't find a list of components for the power board at all. The board was made by Darfon do you think I might find a component list through them?

[tom66]

Re: Sanyo DP32642 No Power

Check if the -04 has a similar enough diagram -- from the looks of it the general architecture is the same.


I don't see a power board schematic for -00, but the layout for both of them is similar.

Chassis number is on the back of the set.

[killian6pk]

Re: Sanyo DP32642 No Power

Yes this helped. It had the same fets in the same arrangement on the board. I was able to read the location for the Diodes and resistors. On the component sheet I was able to find each of the location numbers and get a size etc. for each of them. I then found a data sheet for the diodes. So order is in and I should get them early next week. Will let you know the outcome. Of course I will go blind trying to hold onto and solder them in.

Thanks for the help

[killian6pk]

Re: Sanyo DP32642 No Power

Well got all my parts in and am back at it. I replaced the two bad fets and as Tom suggested the smd resisters and diodes under the fets on the back side of the board. Plug it in and still blew the fuse immediately. I tried to wire an AC 75W light bulb (in a holder) with one wire on either side of fuse location. Could not get it to light the bulb. Not sure if I did this correctly. Soldered one wire to underside of board on one end of fuse and the other wire to the other end of the fuse location. I am getting 117v on one side of fuse when plugged in to AC and some MV reading on the other side of the fuse location. When I could not get the bulb to light I then went on to the next step of testing Diodes.

Pulled one leg of each of the large Diodes and checked them. They all had a reading with negative probe on Cathode side and red probe on anode side. Reversed they all showed OF.

Then I pulled all the small diodes on the front of the board and checked them the same way. Same result reading on one way, OF on the other.

Replaced Thermistor still no power.

While ordering parts I ordered a Bridge Rectifier. Should I replace that also?

Not sure where to go from here.

[tom66]

Re: Sanyo DP32642 No Power

If you're seeing no light from the bulb despite blowing the fuse, I would look for other fuses / broken traces etc.

[coffeeman200]

Re: Sanyo DP32642 No Power

Thanks for the post, I have the exact issue with my other Sanyo TV. Although, i just went the route and replaced the board Looks like i have a weekend project to fix and refurbish.

[killian6pk]

Re: Sanyo DP32642 No Power

Tom
I don't believe I have any broken traces because I traced back along the lines from the Bridge Rectifier (with the beeper) on both sides at least for the first part of the hot side. I will check for another fuse. Did it sound like I had the bulb connected correctly?

[killian6pk]

Re: Sanyo DP32642 No Power

Thanks for the post, I have the exact issue with my other Sanyo TV. Although, i just went the route and replaced the board Looks like i have a weekend project to fix and refurbish.

Let me know if you find anything on yours that might apply to mine.
Thanks

[tom66]

Re: Sanyo DP32642 No Power

Tom
I don't believe I have any broken traces because I traced back along the lines from the Bridge Rectifier (with the beeper) on both sides at least for the first part of the hot side. I will check for another fuse. Did it sound like I had the bulb connected correctly?

You were using the bulb correctly. Strange that it does not light.

[killian6pk]

Re: Sanyo DP32642 No Power

You were using the bulb correctly. Strange that it does not light.

Well the bulb lights now. Not sure what caused it to start up. I changed the Bridge Rectifier (because I had one) and it did not change anything still no AC or DC readings past some odd MV readings like 0.879mv. I do not get any power past the fuse (bulb). There is one other fuse on the board (top side). It is a redish rectangular through the board fuse of 3.15A 250V. When I ohm it out it reads 0.03 at first and drops to 0.01 within a couple of seconds so it appears to be good.

What could stop the AC from not getting past the fuse? Remember I also changed the Thermistor. When I traced the two AC pins on the BRectifier they traced clean back to the plug for the AC with no breaks. So I don't get why the BRec. is not getting power.

[tom66]

Re: Sanyo DP32642 No Power

If the bulb lights up it will drop the full 120VAC so you still have a short somewhere.

[killian6pk]

Re: Sanyo DP32642 No Power

Thanks, do you think it is a shorted component or a trace?

[tom66]

Re: Sanyo DP32642 No Power

Very rare for traces to short.