Toshiba regza 52" sound no picture

[budm]

Re: Toshiba regza 52" sound no picture

BTW, I need good close up pictures (shields removed) of those two inverter boards, and closed up pictures around the connectors of those inverter boards.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

Ok, I removed the inverter board shields and took pics of connectors. There will be pics of the main connector and then one that is in the middle of the board. I will post them first from right side (from rear of tv) and then from left. I also found something interesting that may indicate a problem. I will post those pics after the connectors. these pic are of the whole board and then the connectors rt from rear

[Dan Surra]

Re: Toshiba regza 52" sound no picture





these are same views of left (from rear) inverter board

[Dan Surra]

Re: Toshiba regza 52" sound no picture

OK, when I removed the shields from the left (from rear) inverter board I noticed some imperfections on two yellow cylindrical parts. They could be condensors, I don't know. Each board has 4 of them. Two at top and two at bottom of the board. The top two on left side have a brown substance that has oozed out of the back side. Also, the soldered area on the board itself looks like it may have gotten hot. I have also attached a picture of a set that looks like all the others. Could these two pieces have blown out?

[Dan Surra]

Re: Toshiba regza 52" sound no picture

And I checked the screen with the garage pretty dark. There is no flash of light on the screen that I can see. I also looked from the back of the set with cover removed as I have it, no flash of lights.

[budm]

Re: Toshiba regza 52" sound no picture

OK, when I removed the shields from the left (from rear) inverter board I noticed some imperfections on two yellow cylindrical parts. They could be condensors, I don't know. Each board has 4 of them. Two at top and two at bottom of the board. The top two on left side have a brown substance that has oozed out of the back side. Also, the soldered area on the board itself looks like it may have gotten hot. I have also attached a picture of a set that looks like all the others. Could these two pieces have blown out?

Bad caps!. When those caps are bad, you need to check all the fuses on the inverter board too at this point.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

OK, I am not sure which pieces are the fuses as I do not have diagrams for the inverter boards. However, after looking at them, I checked piece F201, F200, F400, and f401 as they look as if they could be some type of fuseable link. F200,400, and 401 have continuity. F201 is open and I would assume a blown fuse. Also, the yellow parts (capacitors??) with the brown stuff oozing out of them are shorted when I check with an ohm meter. The other 6 yellow pieces are not shorted as I get some kind of reading on ohms setting although I have no clue what I am doing there, sorry. Does this help?

[vinceroger69]

Re: Toshiba regza 52" sound no picture

depending if you want to replace the board or repair it ? yes they are capacitors so they will need changing and i would replace all of them on both boards as two have failed already the rest wont be far away from failing either i guess also you will need to replace that blown fuse im not sure if any other parts maybe damaged as the fuse has blown maybe budm has some more tests you can do? so it all depends on if you can remove and replace the parts yourself.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

thanks vince. I think I can replace the capacitors and fuse. Can you purchase the boards and how much would it cost? I will wait to hear from budm as how to proceed. You guys have been great.
It is interesting to note that I have another set that has same issue (sound but no pic). Both sets quit when my Dish picture was freezing and it was in freeze mode till pic when dark. Can't prove it was related but sure seems suspicious.

[vinceroger69]

Re: Toshiba regza 52" sound no picture

hopefully its just the capacitors that have blown the fuse if so it should be a easy fix are they all 680uf 35 volts? also if you need help with finding the correct fuse replacement upload a picture of the blown one and we will see if we can help you locate the correct one with the capacitors im not sure if you can use panasonic low esr ones in that position on the board budm etc will advise shortly no doubt.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

OK, still waiting to hear from budm. would just replacing that board be an option an affordable option? I will ck on the capacitors but I am pretty sure they are all 680uf 35v.

[vinceroger69]

Re: Toshiba regza 52" sound no picture

maybe have a look on shopjimmy or even ebay as long as the numbers match from your board you should be fine just make sure the buyer has a good returns policy if a faulty item is received as some used items are not always tested.
what is the board number from the faulty invertor board?

[budm]

Re: Toshiba regza 52" sound no picture

You need to get the P/N of those SMD Power MOSFETs with big Tab with 4 legs +1 trimmed leg so you can test the resistance between S pin and the D pin, more likely you will find some shorted out one.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

OH MAN!! Laughing here Budm. What does that say in English (laymens) terms.

[vinceroger69]

Re: Toshiba regza 52" sound no picture

post 44 top picture under the capacitors theres some mosfets (5pins centre leg cut off) whats the part number on them then we can find a data sheet and check the source and drain pins for short circuit faults

im still learing as well so dont worry about asking questions someone will allways advise you oif needed.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

Ok, the 5 pin mosfets (little black square things) with 5 tabs and center one cut #s are (as best I can read them with these old eyes) STU405DH and under that is a small triangle with 7C405. The bottom of the board under these is discolored and brownish. It looks as if I can buy this board relatively cheap. Do you think it is worth a shot or is there a high probability of other issues?

[vinceroger69]

Re: Toshiba regza 52" sound no picture

what sort of price is a replacement board?
STU405DH
Dual E nhancement Mode Field E ffect Transistor ( N and P Channel)

[Dan Surra]

Re: Toshiba regza 52" sound no picture

Around $15. The fuses on the other inverter boards are OK.

[vinceroger69]

Re: Toshiba regza 52" sound no picture

Thats a good price i would buy it at that price you can always repair the old board then as a spare if needed.

[Dan Surra]

Re: Toshiba regza 52" sound no picture

I'll see if it's still available. I will let you know how I make out. thanks vince and budm for all your advice and assistance.